The evolution of human influenza A viruses from 1999 to 2006: A complete genome study

Bragstad, Karoline; Nielsen, Lars Peter; Fomsgaard, Anders

doi:10.1186/1743-422x-5-40

Cited by 92 publications

(92 citation statements)

References 77 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Cross‐protection and cross‐reactivity by DNA vaccines against viruses differing by 11–13% in the HA1 region have been demonstrated by others 41 , 42 , 43 . Altogether, the overall difference between the glycoproteins may play a minor role compared to the location of the discrepancies 22 . We speculate that the pandemic antigens may possess the ability to induce broad cross‐reacting recall antibody responses as these have not yet accumulated glycosylations camouflaging epitopes, and therefore, more conserved epitopes may be available for immune induction 44 , 45 .…”

Section: Discussionmentioning

confidence: 76%

“…These sequons, located in the stalk region of HA1, have become conserved in preceeding strains. There has been an accumulation of sequons, mainly in the globular head of HA, in strains proceeding the first occurring pandemic viruses 22 , 23 , 24 …”

Section: Resultsmentioning

confidence: 99%

“…We have shown that the pandemic HA genes in our DNA vaccines possess the least amount of glycosylations. These sequons have become conserved since then, while preceeding strains have gained additional sequons, mainly in the globular head 22 , 23 , 24 . Therefore, the cross‐reactivity of the pandemic DNA vaccine genes with more recent strains could be related to the limited number of glycosylation sites.…”

Section: Discussionmentioning

confidence: 99%

“…Post‐1999 virus‐challenged ferrets vaccinated with both 1999 DNA and conventional protein vaccines developed cross‐reaction against the 1918‐like H1N1 swine influenza virus from 1931. The reason why the antibodies induced by the conventional trivalent protein vaccine are able to recognise the swine 1931 H1N1 virus and not the H3N2 from 1968 may be that the H1 protein has changed less over time than the H3 protein 22 . This could also explain the better virus clearance observed in the H1N1 experiments.…”

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Pandemic influenza 1918 H1N1 and 1968 H3N2 DNA vaccines induce cross-reactive immunity in ferrets against infection with viruses drifted for decades

Bragstad

Martel

Thomsen

et al. 2010

Influenza and Other Respiratory Viruses

Self Cite

View full text Add to dashboard Cite

Please cite this paper as: Bragstad et al. (2010) Pandemic influenza 1918 H1N1 and 1968 H3N2 DNA vaccines induce cross‐reactive immunity in ferrets against infection with viruses drifted for decades. Influenza and Other Respiratory Viruses 5(1), 13–23. Background Alternative influenza vaccines and vaccine production forms are needed as the conventional protein vaccines do not induce broad cross‐reactivity against drifted strains. Furthermore, fast vaccine production is especially important in a pandemic situation, and broader vaccine reactivity would diminish the need for frequent change in the vaccine formulations. Objective In this study, we compared the ability of pandemic influenza DNA vaccines to induce immunity against distantly related strains within a subtype with the immunity induced by conventional trivalent protein vaccines against homologous virus challenge. Methods Ferrets were immunised by particle‐mediated epidermal delivery (gene gun) with DNA vaccines based on the haemagglutinin (HA) and neuraminidase (NA) and/or the matrix (M) and nucleoprotein genes of the 1918 H1N1 Spanish influenza pandemic virus or the 1968 H3N2 Hong Kong influenza pandemic virus. The animals were challenged with contemporary H1N1 or H3N2 viruses. Results We demonstrated that DNA vaccines encoding proteins of the original 1918 H1N1 pandemic virus induced protective cross‐reactive immune responses in ferrets against infection with a 1947 H1N1 virus and a recent 1999 H1N1 virus. Similarly, a DNA vaccine, based on the HA and NA of the 1968 H3N2 pandemic virus, induced cross‐reactive immune responses against a recent 2005 H3N2 virus challenge. Conclusions DNA vaccines based on pandemic or recent seasonal influenza genes induced cross‐reactive immunity against contemporary virus challenge as good as or superior to contemporary conventional trivalent protein vaccines. This suggests a unique ability of influenza DNA to induce cross‐protective immunity against both contemporary and long‐time drifted viruses.

show abstract

Section: Discussionmentioning

confidence: 76%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Pandemic influenza 1918 H1N1 and 1968 H3N2 DNA vaccines induce cross-reactive immunity in ferrets against infection with viruses drifted for decades

Bragstad

Martel

Thomsen

et al. 2010

Influenza and Other Respiratory Viruses

Self Cite

View full text Add to dashboard Cite

show abstract

“…By studying 413 complete genomes of human H3N2 influenza A viruses collected during 1997-2005 in the United States, Nelson et al (2006) identified stochastic processes as the key determinant of influenza A virus evolution. Bragstad et al (2008) further discovered that the evolution of influenza A virus was stochastically influenced by small "jumps" in genetic distance rather than constant drift, after studying 234 complete genomes of influenza A viruses during 1999-2006 among the Danish.…”

Section: Introductionmentioning

confidence: 99%

Genetic variation analysis of hemagglutinin and neuraminidase of human influenza A/H3N2 virus in Hong Kong (1997-2006)

Shubo¹,

Chen²,

Rao³

et al. 2014

Afr. J. Microbiol. Res.

View full text Add to dashboard Cite

Influenza A virus in Taiwan, 1980–2006: Phylogenetic and antigenic characteristics of the hemagglutinin gene

Wang¹,

Lee

Chan

et al. 2009

Journal of Medical Virology

View full text Add to dashboard Cite

Limited amount of information is available in Taiwan on the genetic or antigenic characteristics of influenza A virus prior to the establishment of a Taiwan surveillance network in 2000. Isolates of H1N1 and H3N2 viruses in Taiwan between 1980 and 2006 were studied, and part of the hemagglutinin gene was analyzed due to its importance in terms of viral infection and antibody neutralization. Results from a phylogenetic analysis indicate continuous evolutionary topology in H3N2 isolates, and two distinct H1N1 lineages. Many genetic relationships between vaccine strains and epidemic isolates appearing in Taiwan before other global locations were also observed and recorded in addition to a gradual increase in the number of N-linked glycosylation sites on partial HA1 proteins since 1980. The results from pairwise comparisons of HA1 nucleotide and deduced amino acid sequences indicate shared identities within groups organized according to their bootstrap and P-values of approximately 95.5-100% and 95.7-100% in H1N1 and 94.5-100% and 93.2-100% in H3N2 viruses, respectively. Comparisons of amino acid substitutions in the five antigenic regions reveal highly non-synonymous changes occurring in the Sb region of H1N1 and in the B region of H3N2. The results of an antigenic analysis using a hemagglutinin inhibition (HI) test indicate the presence of some epidemic strains 1-2 years earlier in Taiwan than in other parts of the world, as well as higher vaccine mismatch rates. This information supports the need for continuous surveillance of emerging influenza viruses in Taiwan, which will be useful for making global vaccine decisions.

show abstract

The evolution of human influenza A viruses from 1999 to 2006: A complete genome study

Cited by 92 publications

References 77 publications

Pandemic influenza 1918 H1N1 and 1968 H3N2 DNA vaccines induce cross-reactive immunity in ferrets against infection with viruses drifted for decades

Pandemic influenza 1918 H1N1 and 1968 H3N2 DNA vaccines induce cross-reactive immunity in ferrets against infection with viruses drifted for decades

Genetic variation analysis of hemagglutinin and neuraminidase of human influenza A/H3N2 virus in Hong Kong (1997-2006)

Influenza A virus in Taiwan, 1980–2006: Phylogenetic and antigenic characteristics of the hemagglutinin gene

Contact Info

Product

Resources

About