Efficacy of trivalent, cold-adapted, influenza virus vaccine against influenza A (Fujian), a drift variant, during 2003-2004.
In the 2003-2004 influenza season, the predominant circulating influenza A (H3N2) virus in the United States was similar antigenically to A/Fujian/411/2002 (H3N2), a drift variant of A/Panama/2007/99 (H3N2), the vaccine strain. That year, a field study of trivalent live-attenuated influenza vaccine (LAIV-T) was conducted in Temple-Belton, Texas, as part of a larger community-based, non-randomized, open-label study in three communities that began in August 1998 [Gaglani MJ, Piedra PA, Herschler GB, Griffith ME, Kozinetz CA, Riggs MW, et al. Direct effectiveness of the trivalent, cold-adapted, influenza virus vaccine (CAIV-T) against the 2000-2001 influenza A (H1N1) and B epidemic in healthy children. Arch Pediatr Adolesc Med 2004;158:65-73; Piedra PA, Gaglani MJ, Kozinetz CA, Herschler G, Riggs M, Griffith M, et al. Herd immunity in adults against influenza-related illnesses with use of the trivalent-live attenuated influenza vaccine (CAIV-T) in children. Vaccine 2005;23:1540-8; Piedra PA, Gaglani MJ, Riggs M, Herschler G, Fewlass C, Watts M, et al. Live attenuated influenza vaccine, trivalent, is safe in healthy children 18 months to 4 years, 5 to 9 years, and 10 to 18 years of age in a community-based, nonrandomized, open-label trial. Pediatrics 2005;116:397-407]. Participants were healthy children aged 5-18 years. The analysis here concerns 6403 children in the Scott & White Health Plan (SWHP) database living within zip codes of the Temple-Belton area, of whom 1706 received LAIV-T and 548 received trivalent inactivated vaccine (TIV) in 2003, 983 had been previously vaccinated in 1998-2001, but not in 2002-2003 or 2003, and 3166 had never been vaccinated. The main outcome measure was medically-attended acute respiratory illness (MAARI). Surveillance culture results were incorporated into the analysis to estimate efficacy against culture-confirmed influenza illness. Vaccine effectiveness of LAIV-T against MAARI was 26% (95% confidence interval (CI) 11, 39). Vaccine efficacy of LAIV-T against culture-confirmed influenza illness including surveillance cultures of children in the SWHP database in the validation calculation was 56% (95% CI 24, 84). LAIV-T was cross-protective with a drift variant strain in 2003-2004, evidence that such vaccines could be important for preparing for a pandemic and for annual influenza.
Halloran
M Elizabeth
ME
Program in Biostatistics and Biomathematics, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA. halloran@fhcrc.org
Piedra
Pedro A
PA
Longini
Ira M
IM
Gaglani
Manjusha J
MJ
Schmotzer
Brian
B
Fewlass
Charles
C
Herschler
Gayla B
GB
Glezen
W Paul
WP
D000281:Administration, Intranasal; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D032521:Immunity, Herd; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000627:therapeutic use*; D007251:Influenza, Human / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D008297:Male; D013781:Texas / Q000453:epidemiology
D007252:Influenza Vaccines