Influenza Vaccine Effectiveness in the United States During 2012–2013: Variable Protection by Age and Virus Type. (18th November 2014)

• Record Type: Journal Article
• Authors: McLean, Huong Q.; Thompson, Mark G.; Sundaram, Maria E.; Kieke, Burney A.; Gaglani, Manjusha; Murthy, Kempapura; Piedra, Pedro A.; Zimmerman, Richard K.; Nowalk, Mary Patricia; Raviotta, Jonathan M.; Jackson, Michael L.; Jackson, Lisa; Ohmit, Suzanne E.; Petrie, Joshua G.; Monto, Arnold S.; Meece, Jennifer K.; Thaker, Swathi N.; Clippard, Jessie R.; Spencer, Sarah M.; Fry, Alicia M.; Belongia, Edward A.
• Is Part Of: Journal of infectious diseases. Volume 211:Number 10(2015:May 15)
• Page Start: 1529
• Page End: 1540
• Publication Date: 2014-11-18
• Subjects: influenza -- vaccine effectiveness -- medically attended influenza; Communicable diseases -- Periodicals; Diseases -- Causes and theories of causation -- Periodicals; Medicine -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.9
• DOI: 10.1093/infdis/jiu647
• Languages: English
• ISSNs: 0022-1899

Abstract

Abstract: Background. During the 2012–2013 influenza season, there was cocirculation of influenza A(H3N2) and 2 influenza B lineage viruses in the United States. Methods. Patients with acute cough illness for ≤7 days were prospectively enrolled and had swab samples obtained at outpatient clinics in 5 states. Influenza vaccination dates were confirmed by medical records. The vaccine effectiveness (VE) was estimated as [100% × (1 − adjusted odds ratio)] for vaccination in cases versus test-negative controls. Results. Influenza was detected in 2307 of 6452 patients (36%); 1292 (56%) had influenza A(H3N2), 582 (25%) had influenza B/Yamagata, and 303 (13%) had influenza B/Victoria. VE was 49% (95% confidence interval [CI], 43%–55%) overall, 39% (95% CI, 29%–47%) against influenza A(H3N2), 66% (95% CI, 58%–73%) against influenza B/Yamagata (vaccine lineage), and 51% (95% CI, 36%–63%) against influenza B/Victoria. VE against influenza A(H3N2) was highest among persons aged 50–64 years (52%; 95% CI, 33%–65%) and persons aged 6 months–8 years (51%; 95% CI, 32%–64%) and lowest among persons aged ≥65 years (11%; 95% CI, −41% to 43%). In younger age groups, there was evidence of residual protection from receipt of the 2011–2012 vaccine 1 year earlier. Conclusions. The 2012–2013 vaccines were moderately effective in most age groups. Cross-lineage protection and residual effects from prior vaccination were observed and warrant further investigation.