Evaluation of Southern Hemisphere influenza vaccine recommendations.
In 1999, the World Health Organization switched from annual to semi-annual recommendations for influenza vaccine composition. We compared the antigenic match between recommendations and circulating viruses before and after 1999, in the Northern and Southern Hemispheres. Vaccine match proportion for A/H3N2 viruses increased from 31% to 59% in the Southern Hemisphere (P<0.05), and is now comparable to that in the Northern Hemisphere. Vaccine match for influenza B decreased from approximately 100% to 33-54% in both hemispheres (P<0.05), following the unexpected resurgence of influenza B/Victoria in 1997. No estimate was available for influenza A/H1N1. We conclude that semi-annual vaccine recommendations are useful overall and discuss potential ways forward, including a recommendation for the improvement of vaccination policy and influenza surveillance in tropical areas.
Richard
Stephanie A
SA
Fogarty International Center, National Institutes of Health, 16 Center Drive,MSC 6705, Building 16, Bethesda, MD 20892, United States. richardst@mail.nih.gov
Viboud
Cécile
C
Miller
Mark A
MA
D006287:Health Planning Guidelines; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification / Q000276:immunology / Q000302:isolation & purification; D053122:Influenza A Virus, H3N2 Subtype / Q000145:classification / Q000276:immunology / Q000302:isolation & purification; D009981:Influenza B virus / Q000145:classification / Q000276:immunology / Q000302:isolation & purification; D007252:Influenza Vaccines / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control* / Q000821:virology
D007252:Influenza Vaccines