tetano
Editor, Senior Moderator
Clin Vaccine Immunol. 2013 Dec 26. [Epub ahead of print]
Genetic and antigenic typing of seasonal influenza breakthrough cases from a 2008-2009 vaccine efficacy trial.
Durviaux S, Treanor J, Beran J, Duval X, Esen M, Feldman G, Frey SE, Launay O, Leroux-Roels G, McElhaney JE, Nowakowski A, Ruiz-Palacios GM, van Essen GA, Oostvogels L, Devaster JM, Walravens K.
Author information
Abstract
The estimation of the effectiveness of vaccination against seasonal influenza is guided by the comparison of antigenicities between influenza virus isolates from clinical breakthrough cases with strains included in the vaccine. This study examined whether the prediction of antigenicity using sequence analysis of the hemagglutinin (HA) gene-encoded HA1-domain could be a simpler alternative to using the conventional hemagglutination inhibition (HI) assay, which requires influenza virus culturing. Specimens were taken from breakthrough cases that occurred in a trivalent influenza vaccine efficacy trial involving over 43000 participants during the 2008-2009 season. A total of 498 influenza viruses were successfully subtyped as A(H3N2) (380), A(H1N1) (29), B(Yamagata) (23) and B(Victoria) (66), from 603 PCR- or culture-confirmed specimens. Unlike the B-strain, most A(H3N2) (377) and all A(H1N1) viruses were designated as homologous to the respective vaccine strains based on the HA1-domain nucleic acid sequence. HI titers relative to the respective vaccine strains and PCR subtyping were determined for 48% (182/380) of A(H3N2) and 86% (25/29) of A(H1N1) viruses. Eighty-four percent of the A(H3N2) and A(H1N1) viruses designated as homologous by sequence were matched to the respective vaccine strains by HI testing. However, these homologous A(H3N2) and A(H1N1) viruses displayed a wide range of relative HI titers. Therefore, although PCR was a sensitive diagnostic method to confirm influenza cases, HA1 sequence analysis appeared to be of limited value in accurately predicting antigenicity and hence may be inappropriate to classify clinical specimens as homologous or heterologous to the vaccine-strain for estimating vaccine efficacy in a prospective clinical trial.
PMID:
24371255
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24371255
Genetic and antigenic typing of seasonal influenza breakthrough cases from a 2008-2009 vaccine efficacy trial.
Durviaux S, Treanor J, Beran J, Duval X, Esen M, Feldman G, Frey SE, Launay O, Leroux-Roels G, McElhaney JE, Nowakowski A, Ruiz-Palacios GM, van Essen GA, Oostvogels L, Devaster JM, Walravens K.
Author information
Abstract
The estimation of the effectiveness of vaccination against seasonal influenza is guided by the comparison of antigenicities between influenza virus isolates from clinical breakthrough cases with strains included in the vaccine. This study examined whether the prediction of antigenicity using sequence analysis of the hemagglutinin (HA) gene-encoded HA1-domain could be a simpler alternative to using the conventional hemagglutination inhibition (HI) assay, which requires influenza virus culturing. Specimens were taken from breakthrough cases that occurred in a trivalent influenza vaccine efficacy trial involving over 43000 participants during the 2008-2009 season. A total of 498 influenza viruses were successfully subtyped as A(H3N2) (380), A(H1N1) (29), B(Yamagata) (23) and B(Victoria) (66), from 603 PCR- or culture-confirmed specimens. Unlike the B-strain, most A(H3N2) (377) and all A(H1N1) viruses were designated as homologous to the respective vaccine strains based on the HA1-domain nucleic acid sequence. HI titers relative to the respective vaccine strains and PCR subtyping were determined for 48% (182/380) of A(H3N2) and 86% (25/29) of A(H1N1) viruses. Eighty-four percent of the A(H3N2) and A(H1N1) viruses designated as homologous by sequence were matched to the respective vaccine strains by HI testing. However, these homologous A(H3N2) and A(H1N1) viruses displayed a wide range of relative HI titers. Therefore, although PCR was a sensitive diagnostic method to confirm influenza cases, HA1 sequence analysis appeared to be of limited value in accurately predicting antigenicity and hence may be inappropriate to classify clinical specimens as homologous or heterologous to the vaccine-strain for estimating vaccine efficacy in a prospective clinical trial.
PMID:
24371255
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24371255