tetano
Editor, Senior Moderator
Clin Infect Dis. 2013 Nov 13. [Epub ahead of print]
Influenza vaccine effectiveness in the 2011-2012 season: protection against each circulating virus and the effect of prior vaccination on estimates.
Ohmit SE, Thompson MG, Petrie JG, Thaker SN, Jackson ML, Belongia EA, Zimmerman RK, Gaglani M, Lamerato L, Spencer SM, Jackson L, Meece JK, Nowalk MP, Song J, Zervos M, Cheng PY, Rinaldo CR, Clipper L, Shay DK, Piedra P, Monto AS.
Source
University of Michigan School of Public Health, Department of Epidemiology, Ann Arbor Michigan, USA.
Abstract
Background. Each year, the US Flu VE Network examines the effectiveness of influenza vaccines in preventing medically-attended acute respiratory illnesses caused by influenza. Methods. Patients with acute respiratory illnesses of <7 days duration were enrolled at ambulatory care facilities in five communities. Specimens were collected and tested for influenza by real-time reverse transcriptase polymerase chain reaction. Receipt of influenza vaccine was defined based on documented evidence of vaccination in medical records or immunization registries. Vaccine effectiveness was estimated in adjusted logistic regression models by comparing the vaccination coverage in those who tested positive for influenza with those who tested negative. Results. The 2011-2012 season was mild and peaked late, with circulation of both type A viruses and both lineages of type B. Overall adjusted vaccine effectiveness was 47% (95% confidence interval [CI], 36 to 56) in preventing medically-attended influenza; vaccine effectiveness was 65% (95% CI, 44 to 79) against type A (H1N1) pdm09, but only 39% (95% CI, 23 to 52) against type A (H3N2). Estimates of vaccine effectiveness against both type B lineages were similar (overall 58%, 95% CI, 35 to 73). An apparent negative effect of prior year vaccination on current year effectiveness estimates was noted, particularly for A (H3N2) outcomes. Conclusions. Vaccine effectiveness in the 2011-2012 season was modest overall, with lower effectiveness against the predominant A (H3N2) virus. This may be related to modest antigenic drift, but past history of vaccination might also play a role.
PMID:
24235265
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24235265
Influenza vaccine effectiveness in the 2011-2012 season: protection against each circulating virus and the effect of prior vaccination on estimates.
Ohmit SE, Thompson MG, Petrie JG, Thaker SN, Jackson ML, Belongia EA, Zimmerman RK, Gaglani M, Lamerato L, Spencer SM, Jackson L, Meece JK, Nowalk MP, Song J, Zervos M, Cheng PY, Rinaldo CR, Clipper L, Shay DK, Piedra P, Monto AS.
Source
University of Michigan School of Public Health, Department of Epidemiology, Ann Arbor Michigan, USA.
Abstract
Background. Each year, the US Flu VE Network examines the effectiveness of influenza vaccines in preventing medically-attended acute respiratory illnesses caused by influenza. Methods. Patients with acute respiratory illnesses of <7 days duration were enrolled at ambulatory care facilities in five communities. Specimens were collected and tested for influenza by real-time reverse transcriptase polymerase chain reaction. Receipt of influenza vaccine was defined based on documented evidence of vaccination in medical records or immunization registries. Vaccine effectiveness was estimated in adjusted logistic regression models by comparing the vaccination coverage in those who tested positive for influenza with those who tested negative. Results. The 2011-2012 season was mild and peaked late, with circulation of both type A viruses and both lineages of type B. Overall adjusted vaccine effectiveness was 47% (95% confidence interval [CI], 36 to 56) in preventing medically-attended influenza; vaccine effectiveness was 65% (95% CI, 44 to 79) against type A (H1N1) pdm09, but only 39% (95% CI, 23 to 52) against type A (H3N2). Estimates of vaccine effectiveness against both type B lineages were similar (overall 58%, 95% CI, 35 to 73). An apparent negative effect of prior year vaccination on current year effectiveness estimates was noted, particularly for A (H3N2) outcomes. Conclusions. Vaccine effectiveness in the 2011-2012 season was modest overall, with lower effectiveness against the predominant A (H3N2) virus. This may be related to modest antigenic drift, but past history of vaccination might also play a role.
PMID:
24235265
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24235265