| low growth ability of recent influenza clinical isolates in mdck cells is due to their low receptor binding affinities. | madin darby canine kidney (mdck) cells have generally been used to isolate influenza viruses from patients. however, in recent years, most fresh isolates of the h3n2 subtype have shown poor growth in mdck cell cultures. such low-growth viruses were often converted to high-growth viruses after several passages through mdck cell cultures. in the present study, viruses were found to lose a potential glycosylation site near the receptor-binding pocket of hemagglutinin (ha), at the same time as they ... | 2006 | 16300986 |
| detailed analysis of the genetic evolution of influenza virus during the course of an epidemic. | the genetic variability of influenza virus is usually studied with sequences selected over numerous years and countries, and rarely within a single season. here we examined the viral evolution and the correlation between genetic and clinical features during an epidemic. from a french prospective household-based study in 1999-2000, 99 infected patients were randomly selected. the ha1 genomic domain was sequenced. phylogenetic analysis showed the existence of two groups of a/h3n2 viruses. we found ... | 2006 | 16316493 |
| safety and efficacy of influenza vaccination in systemic lupus erythematosus patients with quiescent disease. | to assess the safety and efficacy of influenza vaccination in patients with systemic lupus erythematosus (sle), and to evaluate the influence of immunosuppressive drugs on the immune response. | 2006 | 16322083 |
| are swine workers in the united states at increased risk of infection with zoonotic influenza virus? | pandemic influenza strains originate in nonhuman species. pigs have an important role in interspecies transmission of the virus. we examined multiple swine-exposed human populations in the nation's number 1 swine-producing state for evidence of previous swine influenza virus infection. | 2006 | 16323086 |
| anti-influenza virus activity of peramivir in mice with single intramuscular injection. | in the event of an influenza outbreak, antivirals including the neuraminidase (na) inhibitors, peramivir, oseltamivir, and zanamivir may provide valuable benefit when vaccine production is delayed, limited, or cannot be used. here we demonstrate the efficacy of a single intramuscular injection of peramivir in the mouse influenza model. peramivir potently inhibits the neuraminidase enzyme n9 from h1n9 virus in vitro with a 50% inhibitory concentration (ic(50)) of 1.3+/-0.4 nm. on-site dissociatio ... | 2006 | 16325932 |
| molecular evolution of human influenza a/h3n2 virus in asia and europe from 2001 to 2003. | hemagglutinin sequences of 146 human influenza a/h3n2 strains identified in respiratory specimens from asia and europe during the 2001-2003 influenza seasons were analyzed by dna sequencing. our results suggest that four amino acid substitutions, l25i, h75q, h155t, and q156h, led to the antigenic conversion of the previously predominant a/panama/2007/99-like strains to the more recent a/fujian/411/2002-like strains. | 2005 | 16333111 |
| evaluation of a recombinant human adenovirus-5 vaccine administered via needle-free device and intramuscular injection for vaccination of pigs against swine influenza virus. | to evaluate the safety and efficacy of a human adenovirus-5 vaccine for protecting weaned pigs against swine influenza virus subtype h3n2 infection when administered via 2 injection methods. | 2005 | 16334954 |
| [evaluation on the safety and immunogenicity of canada split influenza virus vaccine]. | to evaluate the safety and immunogenicity of canada split influenza virus vaccine. | 2005 | 16335001 |
| influenza and respiratory syncytial virus morbidity among 0-19 aged group in yunus emre health center. | the objective of the study was to determine the morbidity of influenza and respiratory syncytial virus (rsv) infection in the 0-19 years of age group with influenza-like illness among the outpatient cases. from 20 january to 31 march 2003 a total of 123 subjects with upper respiratory tract infection attended yunus emre health center. ninety-one subjects fit the case definition of influenza-like illness, which consisted of acute fever of more than 38 degrees c, cough, and sore throat. after obta ... | 2005 | 16363339 |
| preparing for the next influenza pandemic: lessons from multinational data. | in the past decade, avian influenza has made several incursions of increasing scope and virulence into humans. the likelihood of another pandemic is increasing with time. in work recently published, influenza was found to be the principal cause of the increase in mortality in the united states during the winter months. in a companion report, the u.s. national vaccination program was shown to have increased coverage of high risk groups 5-fold from 1980 to 1999, but excess mortality did not declin ... | 2005 | 16378051 |
| variation in the ability of human influenza a viruses to induce and inhibit the ifn-beta pathway. | we investigated the ability of a selection of human influenza a viruses, including recent clinical isolates, to induce ifn-beta production in cultured cell lines. in contrast to the well-characterized laboratory strain a/pr/8/34, several, but not all, recent isolates of h3n2 viruses resulted in moderate ifn-beta stimulation. through the generation of recombinant viruses, we were able to show that this is not due to a loss of the ability of the ns1 genes to suppress ifn-beta induction; indeed, th ... | 2006 | 16378631 |
| an epidemiologically significant epitope of a 1998 human influenza virus neuraminidase forms a highly hydrated interface in the na-antibody complex. | the crystal structure of the complex between neuraminidase (na) of influenza virus a/memphis/31/98 (h3n2) and fab of monoclonal antibody mem5 has been determined at 2.1a resolution and shows a novel pattern of interactions compared to other na-fab structures. the interface buries a large area of 2400 a2 and the surfaces have high complementarity. however, the interface is also highly hydrated. there are 33 water molecules in the interface>or=95% buried from bulk solvent, but only 13 of these are ... | 2006 | 16384583 |
| surveillance of respiratory virus infections in adult hospital admissions using rapid methods. | both influenza and respiratory syncytial virus (rsv) cause epidemics of respiratory illness of variable severity during the winter season. influenza in particular has been blamed for hospital winter bed pressures, although it is thought that rsv may also play a role. human metapneumovirus (hmpv) is a new respiratory virus reported to be important in children; only a limited number of studies are available for adult populations. we aimed to determine initially the burden of virologically confirme ... | 2006 | 16388686 |
| patterns of influenza-associated mortality among us elderly by geographic region and virus subtype, 1968-1998. | the regular seasonality of influenza in temperate countries is recognized, but regional differences in patterns of influenza-related mortality are poorly understood. identifying patterns could improve epidemic prediction and prevention. the authors analyzed the monthly percentage of deaths attributable to pneumonia and influenza among people aged 65 or more years in the contiguous united states, 1968-1998. the local moran's i test for spatial autocorrelation and correlograms assessing space-time ... | 2006 | 16394205 |
| differences in antibody responses of mice to intranasal or intraperitoneal immunization with influenza a virus and vaccination with subunit influenza vaccine. | two antigenically related but different influenza a virus strains of h3n2 subtype, a/dunedin/ 4/73 (h3n2) (dunedin) and a/mississippi/1/85 (h3n2) (mississippi), were used for intranasal (i.n.) and intraperitoneal (i.p.) immunization of mice and respective antibody responses were compared. in elisa, using purified influenza a virus as antigen, the highest titer of antiviral antibodies was observed after a repeated i.n. infection, in which the dunedin strain was followed by the mississippi strain ... | 2005 | 16402681 |
| genetic and phenotypic stability of cold-adapted influenza viruses in a trivalent vaccine administered to children in a day care setting. | the genetic and phenotypic stability of viruses isolated from young children following intranasal administration of the trivalent live-attenuated influenza virus vaccine (laiv, marketed in the united states as flumist) was evaluated by determination of genomic sequence and assessment of the cold-adapted (ca), temperature-sensitive (ts) and attenuated (att) phenotypes. the complete genomic sequence was determined for 56 independent isolates obtained from children following vaccination (21 type a/ ... | 2006 | 16413592 |
| [antigenic and genetic study of hemagglutinin gene of influenza virus (h3n2) circulated in china in 2004]. | to study the antigenic and genetic characteristics of influenza (h3n2) virus circulated in china in 2004. | 2005 | 16415996 |
| viral pneumonia in older adults. | viruses account for a substantial portion of respiratory illnesses, including pneumonia, in the elderly population. presently, influenza virus a h3n2 and respiratory syncytial virus are the most commonly identified viral pathogens in older adults with viral pneumonia. as diagnostic tests such as reverse-transcription polymerase chain reaction become more widely used, the relative importance of additional viruses (such as parainfluenza, rhinoviruses, coronaviruses, and human metapneumovirus) will ... | 2006 | 16421796 |
| heterocyclic rimantadine analogues with antiviral activity. | 2-(1-adamantyl)-2-methyl-pyrrolidines 3 and 4, 2-(1-adamantyl)-2-methyl-azetidines 5 and 6, and 2-(1-adamantyl)-2-methyl-aziridines 7 and 8 were synthesized and tested for their antiviral activity against influenza a. parent molecules 3, 5, and 7 contain the alpha-methyl-1-adamantan-methanamine 2 pharmacophoric moiety (rimantadine). the ring size effect on anti-influenza a activity was investigated. pyrrolidine 3 was the most potent anti-influenza virus a compound, 9-fold more potent than rimant ... | 2006 | 16439137 |
| influenza pandemics: past, present and future. | influenza a virus is well known for its capability for genetic changes either through antigen drift or antigen shift. antigen shift is derived from reassortment of gene segments between viruses, and may result in an antigenically novel virus that is capable of causing a worldwide pandemic. as we trace backwards through the history of influenza pandemics, a repeating pattern can be observed, namely, a limited wave in the first year followed by global spread in the following year. in the 20th cent ... | 2006 | 16440064 |
| avian influenza viruses and human health. | influenza a viruses cause natural infections of humans, some other mammals and birds. few of the 16 haemagglutinin and nine neuraminidase subtype combinations have been isolated from mammals, but all subtypes have been isolated from birds. in the 20th century, there were four pandemics of influenza as a result of the emergence of antigenically different strains in humans: 1918 (h1n1), 1957 (h2n2), 1968 (h3n2) and 1977 (h1n1). influenza a viruses contain eight distinct rna genes and reassortment ... | 2006 | 16447497 |
| restricted infectivity of a human-lineage h3n2 influenza a virus in pigs is hemagglutinin and neuraminidase gene dependent. | influenza a viruses cause pandemics at sporadic intervals. pandemic viruses can potentially be introduced into the human population through in toto transfer of an avian influenza virus or through reassortment between avian and human strains. pigs are believed to play a central role in the creation of pandemic viruses through reassortment because of their susceptibility to infection with both avian and human influenza viruses. however, we recently found that a human-lineage h3n2 influenza virus w ... | 2006 | 16455873 |
| adamantane resistance among influenza a viruses isolated early during the 2005-2006 influenza season in the united states. | the adamantanes, amantadine and rimantadine, have been used as first-choice antiviral drugs against community outbreaks of influenza a viruses for many years. rates of viruses resistant to these drugs have been increasing globally. rapid surveillance for the emergence and spread of resistant viruses has become critical for appropriate treatment of patients. | 2006 | 16456087 |
| an mf59-adjuvanted inactivated influenza vaccine containing a/panama/1999 (h3n2) induced broader serological protection against heterovariant influenza virus strain a/fujian/2002 than a subunit and a split influenza vaccine. | to test whether inactivated influenza vaccines distributed during the 2003-2004 influenza season in the northern hemisphere were able to confer protection against the mismatched variant a/fujian/411/2002 virus strain, we measured haemagglutination inhibiting (hi) antibodies in elderly subjects vaccinated with three inactivated vaccines against the homologous a/h3n2 vaccine strain (a/panama) and against the mismatched a/fujian strain. the results showed that, while 76 to 80% of elder people vacci ... | 2006 | 16464520 |
| an unexpected antibody response to an engineered influenza virus modifies cd8+ t cell responses. | the ovalbumin(323-339) peptide that binds h2i-a(b) was engineered into the globular heads of hemagglutinin (h) molecules from serologically non-cross-reactive h1n1 and h3n2 influenza a viruses, the aim being to analyze recall cd4+ t cell responses in a virus-induced respiratory disease. prime/challenge experiments with these h1ova and h3ova viruses in h2(b) mice gave the predicted, ovalbumin-specific cd4+ t cell response but showed an unexpectedly enhanced, early expansion of viral epitope-speci ... | 2006 | 16473934 |
| an rna aptamer that distinguishes between closely related human influenza viruses and inhibits haemagglutinin-mediated membrane fusion. | aptamers selected against various kinds of targets have shown remarkable specificity and affinity, similar to those displayed by antibodies to their antigens. to employ aptamers as genotyping reagents for the identification of pathogens and their strains, in vitro selections were carried out to find aptamers that specifically bind and distinguish the closely related human influenza a virus subtype h3n2. the selected aptamer, p30-10-16, binds specifically to the haemagglutinin (ha) region of the ... | 2006 | 16476969 |
| serum antibodies against circulating influenza strains among vaccinated and unvaccinated general practitioners during two consecutive years (2002-2003). | efficacy studies have not answered the question whether influenza vaccination among general practitioners (gps) has a substantial additive effect on their immunity. to evaluate this effect the influenza antibody titres in vaccinated and unvaccinated gps were compared in a controlled trial during two consecutive winter periods (2002-2003 and 2003-2004). the seroprotection rates against the circulating a/h3n2 influenza virus amount to 80% and 42% in the unvaccinated group in 2002 and 2003, respect ... | 2006 | 16490288 |
| influenza pandemics of the 20th century. | three worldwide (pandemic) outbreaks of influenza occurred in the 20th century: in 1918, 1957, and 1968. the latter 2 were in the era of modern virology and most thoroughly characterized. all 3 have been informally identified by their presumed sites of origin as spanish, asian, and hong kong influenza, respectively. they are now known to represent 3 different antigenic subtypes of influenza a virus: h1n1, h2n2, and h3n2, respectively. not classified as true pandemics are 3 notable epidemics: a p ... | 2006 | 16494710 |
| swine influenza a outbreak, fort dix, new jersey, 1976. | in early 1976, the novel a/new jersey/76 (hsw1n1) influenza virus caused severe respiratory illness in 13 soldiers with 1 death at fort dix, new jersey. since a/new jersey was similar to the 1918-1919 pandemic virus, rapid outbreak assessment and enhanced surveillance were initiated. a/new jersey virus was detected only from january 19 to february 9 and did not spread beyond fort dix. a/victoria/75 (h3n2) spread simultaneously, also caused illness, and persisted until march. up to 230 soldiers w ... | 2006 | 16494712 |
| influenza-associated deaths in tropical singapore. | we used a regression model to examine the impact of influenza on death rates in tropical singapore for the period 1996-2003. influenza a (h3n2) was the predominant circulating influenza virus subtype, with consistently significant and robust effect on mortality rates. influenza was associated with an annual death rate from all causes, from underlying pneumonia and influenza, and from underlying circulatory and respiratory conditions of 14.8 (95% confidence interval 9.8-19.8), 2.9 (1.0-5.0), and ... | 2006 | 16494727 |
| [characterization of epidemic influenza virus a(h3n2) strains circulating in russia in the 2003-2004 epidemic season]. | studies indicated that the epidemic rise in the incidence of influenza was caused by its virus a (h3n2) circulation in russia in the 2003-2004 season. the center of influenza ecology and epidemiology investigated 101 epidemic strains isolated the mdck culture. antigenic analysis showed that all viruses a(h3n2) were similar to the reference virus a/fujian/411/02(h3n2) and only 5 strains slightly differed from the latter. twelve (14%) strains resistant to rimantadine at a concentration of 0.5 mg/m ... | 2006 | 16515037 |
| influenza-associated hospitalization in a subtropical city. | the impact of influenza on morbidity and hospitalization in the tropics and subtropics is poorly quantified. uniquely, the hong kong special administrative region has computerized hospital discharge diagnoses on 95% of total bed days, allowing disease burden for a well-defined population to be accurately assessed. | 2006 | 16515368 |
| combination chemotherapy, a potential strategy for reducing the emergence of drug-resistant influenza a variants. | rapid development of resistant influenza variants after amantadine treatment is one of the main drawbacks of m2 blockers. on the other hand, the emergence of variants with low susceptibility to the neuraminidase (na) inhibitors is limited. in the present study we examined whether combination therapy with two classes of anti-influenza drugs can affect the emergence of resistant variants in vitro. we observed that virus yields of human a/nanchang/1/99 (h1n1), a/panama/2007/99 (h3n2), and a/hong ko ... | 2006 | 16516984 |
| [influenza pandemic--current crisis]. | in most cases, influenza is not fatal, even without treatment. moreover, vaccination and antivirals have reduced influenza-related mortality in recent years. however, the direct transmission of avian influenza viruses to humans with lethal outcomes in hong kong in 1997 was a potent reminder of the devastating potential of the disease. currently, h5n1 avian influenza viruses are circulating in many asian countries, and the human death toll continues to rise as the virus spreads to european countr ... | 2006 | 16519118 |
| activation of the intrinsic mitochondrial apoptotic pathway in swine influenza virus-mediated cell death. | the mitochondrial pathway of swine influenza virus (siv)-induced apoptosis was investigated using porcine kidney (pk-15) cells, swine testicle (st) cells, and hela cervical carcinoma cells which are known not to support viral replication. as judged by cell morphology, annexin v staining, and dna fragmentation, pk-15 and st cells infected with three different subtypes of siv (h1n1, h3n2, and h1n2) were obviously killed by apoptosis, not necrosis. siv infection in pk-15 and hela cells was shown to ... | 2006 | 16520548 |
| molecular changes associated with adaptation of human influenza a virus in embryonated chicken eggs. | failure to isolate a/fujian/411/2002 (h3n2) in embryonated chicken eggs resulted in its absence from the 2003/2004 vaccine. we analyzed the adaptation of this virus in eggs during serial passages in the amniotic then allantoic cavities. amniotic passage allowed the virus to grow in the allantoic cavity. during adaptation, 6 amino acid substitutions occurred: 4 in ha (g186v, s219f, v226i, v309i) and 2 in na (e119q, q136k). these substitutions allowed binding to saalpha2,3gal- and saalpha2,6gal-co ... | 2006 | 16545416 |
| comparison between denaturing gradient gel electrophoresis and phylogenetic analysis for characterization of a/h3n2 influenza samples detected during the 1999-2004 epidemics in brazil. | in a preliminary study, a denaturing gradient gel electrophoresis method (dgge) was described for influenza virus variants screening [motta, f.c., rosado, a.s., couceiro, j.n.s.s., 2002. standardization of denaturing gradient gel electrophoresis for mutant screening of influenza a (h3n2) virus samples. j. virol. meth. 105, 105-115]. such a protocol has confirmed its usefulness, discriminating closely related samples by the evaluation of the ha1 portion of haemagglutinin coding rna segment. in th ... | 2006 | 16581139 |
| a recombinant pseudorabies virus encoding the ha gene from h3n2 subtype swine influenza virus protects mice from virulent challenge. | the hemagglutinin (ha) gene of a/swine/inner mogolian/547/2001 (h3n2) swine influenza virus (siv) was recombined into the genome of pseudorabies virus (prv) bartha-k61 vaccine strain, generating a recombinant prv expressing the ha gene, designated as rprv-ha. one group of 15 mice was inoculated intranasally (i.n.) with 10(5.0) pfu of rprv-ha, and another two control groups of mice (15 mice per group) were mock-inoculated or inoculated with bartha-k61. mice inoculated with rprv-ha developed hemag ... | 2006 | 16621018 |
| interfering vaccine (defective interfering influenza a virus) protects ferrets from influenza, and allows them to develop solid immunity to reinfection. | defective interfering (di) virus rnas result from major deletions in full-length viral rnas that occur spontaneously during de novo rna synthesis. these rnas are packaged into virions that are by definition non-infectious, and are delivered to cells normally targeted by the virion. di rnas can only replicate with the aid of a coinfecting infectious helper virus, but the small size of di rna allows more copies of it to be made than of its full-length counterpart, so the cell produces defective vi ... | 2006 | 16621180 |
| bacterial sinusitis and otitis media following influenza virus infection in ferrets. | streptococcus pneumoniae is the leading cause of otitis media, sinusitis, and pneumonia. many of these infections result from antecedent influenza virus infections. in this study we sought to determine whether the frequency and character of secondary pneumococcal infections differed depending on the strain of influenza virus that preceded bacterial challenge. in young ferrets infected with influenza virus and then challenged with pneumococcus, influenza viruses of any subtype increased bacterial ... | 2006 | 16622191 |
| influenza surveillance in victoria, 2005. | influenza activity remained within normal seasonal activity with a well-defined peak at week 29 (beginning 18 july) during the victorian influenza season from may to september 2005. surveillance was based on sentinel general practice influenza-like illness (ili) notifications with laboratory confirmation, medical locum service ili notifications and laboratory notification of influenza detections. one thousand and eighty-seven consultations for ili were reported from 38 general practices, while m ... | 2006 | 16637243 |
| phase i evaluation of intranasal trivalent inactivated influenza vaccine with nontoxigenic escherichia coli enterotoxin and novel biovector as mucosal adjuvants, using adult volunteers. | trivalent influenza virus a/duck/singapore (h5n3), a/panama (h3n2), and b/guandong vaccine preparations were used in a randomized, controlled, dose-ranging phase i study. the vaccines were prepared from highly purified hemagglutinin and neuraminidase from influenza viruses propagated in embryonated chicken eggs and inactivated with formaldehyde. we assigned 100 participants to six vaccine groups, as follows. three intranasally vaccinated groups received 7.5-microg doses of hemagglutinin from eac ... | 2006 | 16641287 |
| isolation and genetic characterization of new reassortant h3n1 swine influenza virus from pigs in the midwestern united states. | since the introduction of h3n2 swine influenza viruses (sivs) into u.s. swine in 1998, h1n2 and h1n1 reassortant viruses have emerged from reassortment between classical h1n1 and h3n2 viruses. in 2004, a new reassortant h3n1 virus (a/swine/minnesota/00395/2004) was identified from coughing pigs. phylogenetic analyses revealed a hemagglutinin segment similar to those of contemporary cluster iii h3n2 sivs and a neuraminidase sequence of contemporary h1n1 origin. the internal genes were of swine, h ... | 2006 | 16641303 |
| t cell responses are better correlates of vaccine protection in the elderly. | it is commonly held that increased risk of influenza in the elderly is due to a decline in the ab response to influenza vaccination. this study prospectively evaluated the relationship between the development of influenza illness, and serum ab titers and ex vivo cellular immune responses to influenza vaccination in community dwelling older adults including those with congestive heart failure (chf). adults age 60 years and older (90 subjects), and 10 healthy young adult controls received the 2003 ... | 2006 | 16670345 |
| [a study on the influenza surveillance program in tianjin, 2004]. | to explore the trend of influenza epidemics, predominate strains of the virus in tianjin city and to analyze the economic impact of vaccine-based interventions for the prevention and control of influenza. | 2005 | 16676603 |
| amplification of the entire genome of influenza a virus h1n1 and h3n2 subtypes by reverse-transcription polymerase chain reaction. | this study describes the development of a simple rt-pcr method to amplify the whole genome of the influenza a virus based on the amplification of full-length gene segments. primers were designed based on the conserved regions of both the 5'-end and the 3'-end of each gene segment. after optimizing the duration and temperature of denaturing, annealing, and extension, these primers could amplify all of the full-length gene segments. to test the accuracy of the method, all amplicons were subjected ... | 2006 | 16687177 |
| novel swine influenza virus subtype h3n1, united states. | influenza a virus infects various animal species and transmits among different hosts, especially between humans and swine. swine may serve as a mixing vessel to create new reassortants that could infect humans. thus, monitoring and characterizing influenza viruses in swine are important in preventing interspecies transmission. we report the emergence and characterization of a novel h3n1 subtype of swine influenza virus (siv) in the united states. phylogenetic analysis showed that the h3n1 sivs m ... | 2006 | 16704839 |
| protection against influenza virus infection by intranasal vaccine with surf clam microparticles (smp) as an adjuvant. | a safe and effective adjuvant is necessary to enhance mucosal immune responses for the development of an inactivated intranasal influenza vaccine. the present study demonstrated the effectiveness of surf clam microparticles (smp) derived from natural surf clams as an adjuvant for an intranasal influenza vaccine. the adjuvant effect of smp was examined when co-administered intranasally with inactivated a/pr8 (h1n1) influenza virus hemagglutinin vaccine in balb/c mice. administration of the vaccin ... | 2006 | 16721854 |
| in vitro inhibition of human influenza a virus replication by chloroquine. | chloroquine is a 9-aminoquinolone with well-known anti-malarial effects. it has biochemical properties that could be applied to inhibit viral replication. we report here that chloroquine is able to inhibit influenza a virus replication, in vitro, and the ic50s of chloroquine against influenza a viruses h1n1 and h3n2 are lower than the plasma concentrations reached during treatment of acute malaria. the potential of chloroquine to be added to the limited range of anti-influenza drugs should be ex ... | 2006 | 16729896 |
| systemic capillary leak syndrome presenting as recurrent shock. | to report a case of systemic capillary leak syndrome (scls) in a child. | 2006 | 16738498 |
| genetic characterization of novel reassortant h1n2 influenza a viruses isolated from pigs in southeastern china. | in december 2004, three influenza h1n2 viruses were isolated from lung samples of pigs that had died from respiratory disease on a farm in southeastern china. to determine the genetic characterization and probable origin, one of the three isolates, a/swine/zhejiang/1/2004 (sw/zj/1/2004), was genetically analyzed. sw/zj/1/2004 was a reassortant with an na gene most closely related to the corresponding gene from a human-like h3n2 virus circulating in 1995. the remaining seven genes were most close ... | 2006 | 16755371 |
| [internal epidemic influenza virus proteins: isolation and investigation]. | the internal influenza virus proteins m1 and rnp free from surface protein impurities were isolated from subviral particles (virions free from ha and na ectomenes). the spikeless particles had no propensity to aggregate in the solution at ph 5.0 as compared with native viruses. the subviral particles of b/hong kong/330/01 influenza virus, which belonged to b/victoria/2/87-lineage, were obtained by proteolytic treatment with the enzyme bromelain under the same conditions as in cases of influenza ... | 2006 | 16756174 |
| epidemiological and virological assessment of influenza activity in europe, during the 2004-2005 winter. | the 2004-2005 influenza season in europe started in late december 2004 and the first influenza activity occurred in the west and southwest (spain, united kingdom and ireland). influenza activity then moved gradually east across europe during january and early february 2005, and from late february until late march, most movement was south to north. the intensity of clinical influenza activity in ten out of 23 countries was higher than during the 2003-2004 season, and lower or equal to the 2003-20 ... | 2006 | 16757850 |
| cross-reactivity of influenza a (h3n2) hemagglutination-inhibition antibodies induced by an inactivated influenza vaccine. | the antigenic drift of influenza a (h3n2) virus in 2003-2004 necessitated a change in the vaccine from the a/panama to the a/wyoming strain for the 2004-2005 season. using hemagglutination inhibition, we therefore tested antibodies in sera of 39 individuals (mean age 64.6 years) at the end of the 2003-2004 season for cross-reactivity to vaccine strains and h3n2 antigens subject to antigenic drift. antibodies against both a (h3n2) panama and wyoming developed in 5/13 (38.5%) unvaccinated individu ... | 2006 | 16777274 |
| [influenza diagnostics in patient with leukemia suspicion]. | influenza is a seasonal viral disease, with the peak of morbidity occurring in poland between january and march. it is estimated that up to 70% of respiratory infections during the season is caused by this virus. influenza virus infection poses an ultimate threat to the elderly > or = 65 years old and chronically ill, in whom postinfluenzal complications--including viral pneumonia and secondary bacterial pneumonia--cause from 0.1% to 0.4% deaths annually. influenza also triggers off from 5% to 7 ... | 2006 | 16780271 |
| the guinea pig as a transmission model for human influenza viruses. | the severity of epidemic and pandemic influenza outbreaks is dictated in part by the efficiency with which the causative strain transmits between human hosts. the mechanisms underlying influenza virus spread are poorly understood, in part because of the lack of a convenient animal model to study this phenomenon. indeed, despite extremely efficient transmission among humans and virulence in the mouse model, we have shown that even the 1918 pandemic influenza virus does not transmit between mice. ... | 2006 | 16785447 |
| [diagnostics of viral respiratory infections in hospitalized patients and ambulatory patients from sentinel program during 2004/05 season in poland]. | the aim of the study was to evaluate an impact of respiratory infections on the study population, type/subtype of influenza viruses circulating during 2004/05 season within the groups of hospitalised (n=35) and ambulatory patients (n=420) and to determine antigenic affinity of isolated viral strains. laboratory diagnostics of influenza a and b type, rsv, adenovirus and parainfluenzavirus (type 1, 2 and 3) was performed using direct immunofluorescence test (difa), virus isolation on mdck cell lin ... | 2005 | 16789521 |
| [sequence analysis of the ha1 regions of hemagglutinin genes of influenza viruses (h3n2) isolated from children in beijing from 1998 - 2004]. | to characterize the ha1 regions of hemagglutinin gene of influenza viruses (h3n2) isolated from children in beijing from 1998 - 2004. | 2006 | 16792896 |
| amantadine resistance among porcine h1n1, h1n2, and h3n2 influenza a viruses isolated in germany between 1981 and 2001. | this study was designed to gain insight into amantadine susceptibility of porcine influenza a viruses isolated in germany between 1981 and 2001. the 12 studied h1n1, h1n2, and h3n2 porcine influenza virus strains were isolated in chicken eggs and passaged once in mdck cells. plaque reduction assays were applied to examine virus susceptibility to amantadine. genotyping was used to confirm drug resistance. in the results of these antiviral studies, only 3 of the 12 isolates were shown to be amanta ... | 2006 | 16809934 |
| single amino acid substitutions in the hemagglutinin of influenza a/singapore/21/04 (h3n2) increase virus growth in embryonated chicken eggs. | most of the recently circulating h3n2 influenza a strains do not replicate well in embryonated chicken eggs and had to be isolated by cell culture, which presents a great challenge for influenza vaccine production using embryonated chicken eggs. we previously reported that a human h3n2 virus, a/fujian/411/02, which replicates poorly in eggs, could be improved by changing a minimum of two ha residues (g186v/v226i or h183l/v226a). here, we extended our work to the a/singapore/21/04 strain that was ... | 2006 | 16814431 |
| [adamantane resistance among influenza a (h3n2) viruses isolated from the mainland of china]. | to study the incidence of adamantane resistance among influenza a (h3n2) viruses isolated from the mainland of china since 1989 through our influenza surveillance system, and to provide more information for the clinical usage of adamantane drugs. | 2006 | 16816855 |
| natural selection on the influenza virus genome. | influenza viruses are the etiological agents of influenza. although vaccines and drugs are available for the prophylaxis and treatment of influenza virus infections, the generation of escape mutants has been reported. to develop vaccines and drugs that are less susceptible to the generation of escape mutants, it is important to understand the evolutionary mechanisms of the viruses. here natural selection operating on all the proteins encoded by the h3n2 human influenza a virus genome was inferre ... | 2006 | 16818477 |
| identification of genetic diversity by cultivating influenza a(h3n2) virus in vitro in the presence of post-infection sera from small children. | antigenic variants probably arise in the field by escaping herd immunity. we have earlier found that sera from small children are more strain-specific than sera from adults and could therefore, provide favourable conditions for selecting antigenic escape mutants. we had access to small volumes of anonymous sera collected in norway after the epidemic season 1999/00, which was dominated by the a/panama/2007/99 (h3n2) variant. the ha gene of the representative strain of that season was genetically ... | 2006 | 16844271 |
| genomic analysis of influenza a viruses, including avian flu (h5n1) strains. | this study was designed to conduct genomic analysis in two steps, such as the overall relative synonymous codon usage (rscu) analysis of the five virus species in the orthomyxoviridae family, and more intensive pattern analysis of the four subtypes of influenza a virus (h1n1, h2n2, h3n2, and h5n1) which were isolated from human population. all the subtypes were categorized by their isolated regions, including asia, europe, and africa, and most of the synonymous codon usage patterns were analyzed ... | 2006 | 16858618 |
| evidence of a cross-protective immune response to influenza a in the cotton rat model. | epidemiologic evidence suggests that cross-protective immune responses to influenza a viruses that have different hemagglutinin and neuraminidase subtypes occur in humans. this study characterized this heterosubtypic immunity in cotton rats (sigmodon hispidus). animals were infected with influenza a/pr/8/34 (h1n1) or a/wuhan/359/95 (h3n2), and then challenged with a/wuhan/359/95(h3n2) virus 4 weeks later. viral titers, respiratory rates, and pathology of the respiratory tract following primary a ... | 2006 | 16860444 |
| infection of human airway epithelium by human and avian strains of influenza a virus. | we describe the characterization of influenza a virus infection of an established in vitro model of human pseudostratified mucociliary airway epithelium (hae). sialic acid receptors for both human and avian viruses, alpha-2,6- and alpha-2,3-linked sialic acids, respectively, were detected on the hae cell surface, and their distribution accurately reflected that in human tracheobronchial tissue. nonciliated cells present a higher proportion of alpha-2,6-linked sialic acid, while ciliated cells po ... | 2006 | 16873262 |
| prevention and control of influenza: recommendations of the advisory committee on immunization practices (acip). | this report updates the 2005 recommendations by the advisory committee on immunization practices (acip) regarding the use of influenza vaccine and antiviral agents (cdc. prevention and control of influenza: recommendations of the advisory committee on immunization practices [acip]. mmwr 2005;54[no. rr-8]:1--44). the 2006 recommendations include new and updated information. principal changes include 1) recommending vaccination of children aged 24-59 months and their household contacts and out-of- ... | 2006 | 16874296 |
| influenza-related mortality in the italian elderly: no decline associated with increasing vaccination coverage. | we investigated trends in influenza-related mortality among the elderly population in italy associated with increased vaccination coverage. using italian vital statistics data, we studied monthly death rates for pneumonia and influenza and all-cause for persons >/=65 years of age by 5-year age groups for 1970-2001. using a classic seasonal regression modelling approach, we estimated the age-specific seasonal excess mortality rates among italian elderly as a measure of influenza-related deaths. w ... | 2006 | 16876293 |
| lack of transmission of h5n1 avian-human reassortant influenza viruses in a ferret model. | avian influenza a h5n1 viruses continue to spread globally among birds, resulting in occasional transmission of virus from infected poultry to humans. probable human-to-human transmission has been documented rarely, but h5n1 viruses have not yet acquired the ability to transmit efficiently among humans, an essential property of a pandemic virus. the pandemics of 1957 and 1968 were caused by avian-human reassortant influenza viruses that had acquired human virus-like receptor binding properties. ... | 2006 | 16880383 |
| experimental evaluation of the fluchip diagnostic microarray for influenza virus surveillance. | global surveillance of influenza is critical for improvements in disease management and is especially important for early detection, rapid intervention, and a possible reduction of the impact of an influenza pandemic. enhanced surveillance requires rapid, robust, and inexpensive analytical techniques capable of providing a detailed analysis of influenza virus strains. low-density oligonucleotide microarrays with highly multiplexed "signatures" for influenza viruses offer many of the desired char ... | 2006 | 16891504 |
| mutations conferring zanamivir resistance in human influenza virus n2 neuraminidases compromise virus fitness and are not stably maintained in vitro. | viruses resistant to zanamivir have been generated in vitro, but no resistant virus has yet been isolated from a zanamivir-treated immunocompetent patient. in contrast most resistant viruses isolated from oseltamivir-treated patients correspond to those selected in vitro. however, despite mutations being in conserved residues in the neuraminidase (na) they do not confer resistance in all na subtypes. | 2006 | 16891631 |
| impaired long-chain fatty acid metabolism in mitochondria causes brain vascular invasion by a non-neurotropic epidemic influenza a virus in the newborn/suckling period: implications for influenza-associated encephalopathy. | the neuropathogenesis of influenza-associated encephalopathy in children and reye's syndrome remains unclear. a surveillance effort conducted during 2000-2003 in south-west japan reveals that almost all fatal and handicapped influenza-associated encephalopathy patients exhibit a disorder of mitochondrial beta-oxidation with elevated serum acylcarnitine ratios (c(16:0)+c(18:1))/c(2). here we show invasion by a non-neurotropic epidemic influenza a h3n2 virus in cerebral capillaries with progressiv ... | 2007 | 16896540 |
| outbreak of influenza amongst residential school students in malaysia. | in the months of july and august 2003, an outbreak of acute respiratory illness caused by influenza a virus occurred among students in seven residential schools situated in the northern part (perak) of peninsular malaysia. out of 4989 students, aged 13 to 18 years (mean = 15.9), 1419 (28%) were effected by influenza-like illness. all patients were treated as outpatients except for 36 students who required admission for high fever, severe coughing and shortness of breath. abnormal chest x-ray fin ... | 2006 | 16898307 |
| a cell-based luminescence assay is effective for high-throughput screening of potential influenza antivirals. | the spread of highly pathogenic avian influenza across geographical and species barriers underscores the increasing need for novel antivirals to compliment vaccination and existing antiviral therapies. identification of new antiviral lead compounds depends on robust primary assays for high-throughput screening (hts) of large compound libraries. we have developed a cell-based screen for potential influenza antivirals that measures the cytopathic effect (cpe) induced by influenza virus (a/udorn/72 ... | 2007 | 16904762 |
| importance of neuraminidase active-site residues to the neuraminidase inhibitor resistance of influenza viruses. | neuraminidase inhibitors (nais) are antivirals designed to target conserved residues at the neuraminidase (na) enzyme active site in influenza a and b viruses. the conserved residues that interact with nais are under selective pressure, but only a few have been linked to resistance. in the a/wuhan/359/95 (h3n2) recombinant virus background, we characterized seven charged, conserved na residues (r118, r371, e227, r152, r224, e276, and d151) that directly interact with the nais but have not been r ... | 2006 | 16912325 |
| addition of a prominent epitope affects influenza a virus-specific cd8+ t cell immunodominance hierarchies when antigen is limiting. | a reverse genetics strategy was used to insert the ova peptide (amino acid sequence siinfekl; ova(257-264)) into the neuraminidase stalk of both the a/pr8 (h1n1) and a/hkx31 (h3n2) influenza a viruses. initial characterization determined that k(b)ova257 is presented on targets infected with pr8-ova and hk-ova without significantly altering d(b) nucleoprotein (np)366 presentation. there were similar levels of k(b)ova257- and d(b)np366-specific ctl expansion following both primary and secondary in ... | 2006 | 16920927 |
| influenza a outbreak in a community hospital. | in january 2005, the department of public health, hse eastern region, received notification of an outbreak of influenza-like illness (ili) in a community hospital for elderly patients. influenza a (h3n2 subtype) was isolated in 12 of 18 (66%) throat swabs sent to the national virus reference laboratory (nvrl). an outbreak control team was convened. infection control measures were put in place. immunisation clinics were organised for non-immunised staff. the epidemic curve confirmed peak onset of ... | 2006 | 16921823 |
| virus-epitope vaccine design: informatic matching the hla-i polymorphism to the virus genome. | attempts to develop peptide vaccines, based on a limited number of peptides face two problems: hla polymorphism and the high mutation rate of viral epitopes. we have developed a new genomic method that ensures maximal coverage and thus maximal applicability of the peptide vaccine. the same method also promises a large number of epitopes per hla to prevent escape via mutations. our design can be applied swiftly in order to face rapidly emerging viral diseases. we use a genomic scan of all candida ... | 2007 | 16930710 |
| overcoming maternal antibody interference by vaccination with human adenovirus 5 recombinant viruses expressing the hemagglutinin and the nucleoprotein of swine influenza virus. | sows and gilts lack immunity to human adenovirus 5 (ad-5) vectored vaccines so immunogens of swine pathogens can be expressed with these vaccines in order to immunize suckling piglets that have interfering, maternally derived antibodies. in this study 7-day-old piglets, that had suckled h3n2 infected gilts, were sham-inoculated with a non-expressing ad-5 vector or given a primary vaccination with replication-defective ad-5 viruses expressed the h3 hemagglutinin and the nucleoprotein of swine inf ... | 2006 | 16939702 |
| vaccination of pigs against swine influenza viruses by using an ns1-truncated modified live-virus vaccine. | swine influenza viruses (siv) naturally infect pigs and can be transmitted to humans. in the pig, genetic reassortment to create novel influenza subtypes by mixing avian, human, and swine influenza viruses is possible. an siv vaccine inducing cross-protective immunity between different subtypes and strains circulating in pigs is highly desirable. previously, we have shown that an h3n2 siv (a/swine/texas/4199-2/98 [tx98]) containing a deleted ns1 gene expressing a truncated ns1 protein of 126 ami ... | 2006 | 16943300 |
| a fused gene of nucleoprotein (np) and herpes simplex virus genes (vp22) induces highly protective immunity against different subtypes of influenza virus. | we evaluated the immunogenicity and protective activity of plasmid dna vaccines encoding the influenza virus np gene (pnp) alone or in combination with the herpes simplex virus type 1 protein 22 gene (pvp22). optimal immune responses were observed in balb/c mice immunized with the combination of pvp22 plus pnp, as assessed by enzyme-linked immunosorbent assay (elisa), enzyme-linked immunospot (elispot) and intracellular cytokine staining (iccs). these mice also showed maximal resistance followin ... | 2006 | 16945400 |
| immunization with trivalent inactivated influenza vaccine in partially immunized toddlers. | children > or = 6 months of age who have previously received 1 dose of trivalent inactivated influenza vaccine are recommended to be given an additional single trivalent inactivated influenza vaccine dose the following fall. limited data exist documenting the immunogenicity of 2 doses of influenza vaccine given in separate years to young children, and it is not known if the antigen content of each of the 2 doses of vaccine must be identical or similar to optimally immunize children in this age g ... | 2006 | 16950949 |
| evaluation of hemagglutinin subtype 1 swine influenza viruses from the united states. | swine influenza viruses (siv) of the hemagglutinin subtype 1 (h1) isolated from the united states (u.s.) have not been well-characterized in the natural host. an increase in the rate of mutation and reassortment has occurred in siv isolates from the u.s. since 1998, including viruses belonging to the h1 subtype. two independent animal studies were done to evaluate and compare the pathogenesis of 10 siv isolates dating from 1930 to currently circulating isolates. in addition, the hemagglutinin an ... | 2006 | 16962262 |
| inhibition of multiple subtypes of influenza a virus in cell cultures with morpholino oligomers. | peptide-conjugated phosphorodiamidate morpholino oligomers (p-pmo) are single-stranded nucleic acid-like antisense agents that can reduce gene expression by sterically blocking complementary rna sequence. p-pmo are water soluble and nuclease resistant, and they readily achieve uptake into cells in culture under standard conditions. eight p-pmo, each 20 to 22 bases in length, were evaluated for their ability to inhibit influenza a virus (fluav) a/pr/8/34 (h1n1) replication in cell culture. the p- ... | 2006 | 16966399 |
| serological profiles after consecutive experimental infections of pigs with european h1n1, h3n2, and h1n2 swine influenza viruses. | swine influenza viruses (sivs) of h1n1, h3n2, and h1n2 subtypes, with antigenically different hemagglutinins, are currently cocirculating in pigs in europe. this study aimed to determine whether the hemagglutination inhibition (hi) test, which is the primary serological test for siv, is sufficiently specific to discriminate between infections with the three subtypes. in experiment 1, pigs were consecutively inoculated with european h1n1, h3n2, and h1n2 sivs by the intranasal route, or with the r ... | 2006 | 16987057 |
| primary influenza a virus infection induces cross-protective immunity against a lethal infection with a heterosubtypic virus strain in mice. | in order to assess the level of protection against a lethal influenza virus infection provided by a primary infection with a virus strain of another subtype, c57bl/6 mice were infected with the sublethal influenza virus x-31 (h3n2) and subsequently challenged with the lethal strain a/pr/8/34 (h1n1). the outcome of the challenge infection was compared with that in mice that did not experience an infection with influenza virus x-31 prior to the challenge infection. the x-31 experienced mice cleare ... | 2007 | 17005299 |
| superior relative efficacy of live attenuated influenza vaccine compared with inactivated influenza vaccine in young children with recurrent respiratory tract infections. | young children have a high incidence of influenza and influenza-related complications. this study compared the efficacy and safety of cold-adapted influenza vaccine, trivalent (caiv-t) with trivalent inactivated influenza vaccine (tiv) in young children with a history of recurrent respiratory tract infections (rtis). | 2006 | 17006279 |
| antibody responses after dose-sparing intradermal influenza vaccination. | reduced-dose intradermal (id) influenza vaccination is an attractive approach to increase availability of vaccine supply in an event of vaccine shortage. we conducted a randomized open-label study, in which 500 subjects were randomly assigned to receive an id injection of 0.1 ml dose of inactivated split-virion influenza vaccine or an im injection of 0.5 ml dose. the subjects who had hemagglutination inhibition (hi) antibody titer of at least 1:40 at day 28 post-vaccination in id and im groups w ... | 2007 | 17011678 |
| longitudinal analysis of genotype distribution of influenza a virus from 2003 to 2005. | influenza a viruses cause yearly epidemics, in part, due to their ability to overcome immunity from previous infections through acquisition of mutations. amino acid sequences encoded by genes 4 (ha), 6 (na), 7 (m), and 8 (ns) from 77 h3n2 influenza a isolates, collected between november 2003 and march 2005, were analyzed to determine the extent to which the viruses mutated within epidemic periods and between the epidemics. nucleotide and amino acid sequences were stable throughout the epidemics ... | 2006 | 17021086 |
| reassortment between human a(h3n2) viruses is an important evolutionary mechanism. | phylogenetic relationships of whole genomes of h3n2 viruses circulating in germany during a 6-year period from 1998 to 2005 revealed the co-circulation of different lineages of viruses. multiple reassortment events occurred during this time between viruses belonging to different lineages or different subgroups. strains isolated during 1998-1999 were characterised by a surprisingly high heterogeneity and multiple reassortment events. seventy percent of the examined 1998-1999 viruses had completel ... | 2006 | 17030498 |
| [expression of host genes in influenza virus infected cells]. | when nci-h292 human bronchial epithelial cells were infected with influenza a/udorn/72(h3n2) virus, 152 host genes were identified as virus-stimulated genes (vsgs). the expression of these genes was increased more than 4-fold by the virus infection and reached to the level of more than one copy per cell. seventy-three vsgs were also stimulated by interferon-beta (ifn-beta) treatment and they contained the genes known to possess antiviral activity. as a likely consequence, the production of proge ... | 2006 | 17037354 |
| a non-living nasal influenza vaccine can induce major humoral and cellular immune responses in humans without the need for adjuvants. | twenty-eight healthy adult volunteers were immunized intranasally with an inactivated whole-virus influenza vaccine based on the strain a/new caledonia/20/99 (h1n1), either in saline or mixed with formaldehyde-inactivated bordetella pertussis as a mucosal adjuvant, or in a thixotropic vehicle with mucoadhesive properties. after four doses, all groups of vaccinees developed significant igg- and iga-antibody responses, measured by elisa, in respectively serum and nasal secretions. none of the volu ... | 2005 | 17038826 |
| phase i, randomized, controlled trial to study the reactogenicity and immunogenicity of a nasal, inactivated trivalent influenza virus vaccine in healthy adults. | we performed a randomized, placebo-controlled, dose-escalating clinical trial to evaluate the safety and immunogenicity of an inactivated, split virion, trivalent, nasal influenza vaccine using lipid/polysaccharide molecules as carriers. a total of 64 adults (mean age 29; range 19-69 years) were randomly allocated to receive a mixture of lipid/polysaccharide carrier molecules and 7.5, 15, or 30 microg hemagglutinin antigen of each of the three influenza strains (a/johannesburg/82/96 [h1n1], a/na ... | 2005 | 17038827 |
| [surveillance for influenza a virus infections in infants and young children in beijing, china, 2001-2005]. | to characterize the prevalence and antigenic drift of influenza a viruses isolated during the period from 2001 to 2005 in infants and young children in beijing. | 2006 | 17044978 |
| dose-related safety and immunogenicity of baculovirus-expressed trivalent influenza vaccine: a double-blind, controlled trial in adult patients with non-hodgkin b cell lymphoma. | in 27 patients randomized to receive commercial trivalent influenza vaccine (tiv) containing 15 microg of the hemagglutinin (ha) of influenza a (h3n2 and h1n1) and b virus or a recombinant vaccine (rhao) containing 15, 45, or 135 microg of each ha, reactogenicity was minor. among patients with similar prevaccination titers, 40% given 45 microg and 60% given 135 microg of rhao developed an increase in influenza a/h3 neutralizing antibody levels; there were no increases in 4 given tiv. for each va ... | 2006 | 17054068 |
| rapid sequencing of the non-coding regions of influenza a virus. | the non-coding regions (ncrs) of influenza a virus gene segments play a crucial role in the viral replication cycle. although the ncrs are considered to be conserved, some variation does exist, that affects viral replication. therefore, a rapid method to sequence the 5' and 3' ncrs was designed. this method is based on ligation of viral rna, rt reactions and subsequent pcr with primersets consisting of a gene segment specific primer and a primer designed across the junction of the 5' and 3' ends ... | 2007 | 17059848 |
| [an adult case of acute cerebellitis after influenza a infection with a cerebellar corical lesion on mri]. | we report an adult case of acute cerebellitis associated with influenza a. a 25-year-old woman with fever and headache was diagnosed as having influenza a infection, because nasal swab extract was found positive in the influenza assay. she was treated with oseltamivir. after the treatment, she gradually developed gait and speech disturbance. neurological examination revealed dysarthria with scanning slurred speech, and limb and truncal ataxia. cerebrospinal fluid showed pleocytosis and a four-fo ... | 2006 | 17061703 |
| long intervals of stasis punctuated by bursts of positive selection in the seasonal evolution of influenza a virus. | the interpandemic evolution of the influenza a virus hemagglutinin (ha) protein is commonly considered a paragon of rapid evolutionary change under positive selection in which amino acid replacements are fixed by virtue of their effect on antigenicity, enabling the virus to evade immune surveillance. | 2006 | 17067369 |
| [avian influenza viruses--new causative agents of human infections]. | introduction: influenza a viruses can infect humans, some mammals and especially birds. subtypes of human influenza a viruses: a(h1n1), a(h2n2) and a(h3n2) have caused pandemics. avian influenza viruses vary owing to their 15 hemagglutinins (h) and 9 neuraminidases (n). human cases of avian influenza a: in the netherlands in 2003, there were 83 human cases of influenza a (h7n7). in 1997, 18 cases of h5n1 influenza a, of whom 6 died, were found among residents of hong kong. in 2004, 34 human case ... | 2006 | 17068888 |
| response to influenza vaccine in people with non-protective hi antibody titers. | the purpose of the study was to determine which factors correlate directly with response to vaccination in such a group of subjects with non-protective hi antibody titers before vaccination. two vaccines were used, a subunit virus vaccine adjuvanted with mf59 and a split virus vaccine. the analysis indicated that immunization with vaccine adjuvanted with mf59 was an independent variable for immune response against a/h3n2 (or: 3.51; 95% ci: 1.81-6.79) and b (or: 2.31; 95% ci: 1.37-3.89). the resu ... | 2006 | 17082899 |