tetano
Editor, Senior Moderator
J Infect Dis. 2014 Jan 19. [Epub ahead of print]
Influenza A/subtype and B/lineage effectiveness estimates for the 2011-12 trivalent vaccine: cross-season and cross-lineage protection with unchanged vaccine.
Skowronski DM, Janjua NZ, Sabaiduc S, De Serres G, Winter AL, Gubbay JB, Dickinson JA, Fonseca K, Charest H, Bastien N, Li Y, Kwindt TL, Mahmud SM, Van Caeseele P, Krajden M, Petric M.
Author information
Abstract
Background. We estimate vaccine effectiveness (VE) against both influenza A/subtypes and B/lineages in Canada for the 2011-12 trivalent inactivated influenza vaccine (TIV) with components entirely unchanged from 2010-11 and in the context of phenotypic and genotypic characterization of circulating viruses.Methods. In a test-negative case-control study VE was estimated as [1-adjustedOddsRatio]X100 for RT-PCR-confirmed influenza in vaccinated versus non-vaccinated participants. Viruses were characterized by hemagglutination-inhibition (HI) and sequencing of antigenic sites of the hemagglutinin (HA) gene.Results. There were 1507 participants. VE against A(H1N1)pdm09 was 80%(95%CI:52-92%): circulating viruses were HI-characterized as vaccine-matched and bore just 2 amino-acid (AA) differences from vaccine. VE against A/H3N2 was 51%(95%CI:10-73%): circulating viruses were HI-characterized as vaccine-related but bore ≥11AA differences from vaccine. VE against influenza/B was 51%(95%CI:26-67%): 71%(95%CI:40-86%) for lineage-matched B/Victoria and 27%(95%CI-21-56%) for lineage-mismatched B/Yamagata. For both influenza A and B types, VE was similar among recipients of either 2010-11 or 2011-12 TIV alone, higher when vaccinated both seasons.Conclusions. Phenotypic and genotypic characterization of circulating and vaccine viruses enhances understanding of TIV performance, shown in 2011-12 to be substantial against well-conserved A(H1N1)pdm09 and lineage-matched influenza/B, suboptimal against genetic-variants of A/H3N2 and further reduced against lineage-mismatched influenza/B. With unchanged vaccine components, protection may extend beyond a single season.
PMID:
24446529
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24446529
Influenza A/subtype and B/lineage effectiveness estimates for the 2011-12 trivalent vaccine: cross-season and cross-lineage protection with unchanged vaccine.
Skowronski DM, Janjua NZ, Sabaiduc S, De Serres G, Winter AL, Gubbay JB, Dickinson JA, Fonseca K, Charest H, Bastien N, Li Y, Kwindt TL, Mahmud SM, Van Caeseele P, Krajden M, Petric M.
Author information
Abstract
Background. We estimate vaccine effectiveness (VE) against both influenza A/subtypes and B/lineages in Canada for the 2011-12 trivalent inactivated influenza vaccine (TIV) with components entirely unchanged from 2010-11 and in the context of phenotypic and genotypic characterization of circulating viruses.Methods. In a test-negative case-control study VE was estimated as [1-adjustedOddsRatio]X100 for RT-PCR-confirmed influenza in vaccinated versus non-vaccinated participants. Viruses were characterized by hemagglutination-inhibition (HI) and sequencing of antigenic sites of the hemagglutinin (HA) gene.Results. There were 1507 participants. VE against A(H1N1)pdm09 was 80%(95%CI:52-92%): circulating viruses were HI-characterized as vaccine-matched and bore just 2 amino-acid (AA) differences from vaccine. VE against A/H3N2 was 51%(95%CI:10-73%): circulating viruses were HI-characterized as vaccine-related but bore ≥11AA differences from vaccine. VE against influenza/B was 51%(95%CI:26-67%): 71%(95%CI:40-86%) for lineage-matched B/Victoria and 27%(95%CI-21-56%) for lineage-mismatched B/Yamagata. For both influenza A and B types, VE was similar among recipients of either 2010-11 or 2011-12 TIV alone, higher when vaccinated both seasons.Conclusions. Phenotypic and genotypic characterization of circulating and vaccine viruses enhances understanding of TIV performance, shown in 2011-12 to be substantial against well-conserved A(H1N1)pdm09 and lineage-matched influenza/B, suboptimal against genetic-variants of A/H3N2 and further reduced against lineage-mismatched influenza/B. With unchanged vaccine components, protection may extend beyond a single season.
PMID:
24446529
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24446529