title: Cross-immunity and age patterns of influenza A(H5N1) infection.
abstract: The age distribution of influenza A(H5N1) cases reported during 2006-2013 varied substantially between countries. As well as underlying demographic profiles, it is possible that cross-immunity contributed to the age distribution of reported cases: seasonal influenza A(H1N1) and avian influenza A(H5N1) share the same neuraminidase subtype, N1. Using a mechanistic model, we measured the extent to which population age distribution and heterosubtypic cross-immunity could explain the observed age patterns in Cambodia, China, Egypt, Indonesia and Vietnam. Our results support experimental evidence that prior infection with H1N1 confers partial cross-immunity to H5N1, and suggest that more than 50% of spillover events did not lead to reported cases of infection as a result. We also identified age groups that have additional risk factors for influenza A(H5N1) not captured by demography or infection history.
authors.affiliation: Department of Infectious Disease Epidemiology,London School of Hygiene & Tropical Medicine,London,UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Kucharski
authors.affiliation: Department of Infectious Disease Epidemiology,London School of Hygiene & Tropical Medicine,London,UK.
authors.forename: W J
authors.initials: WJ
authors.lastname: Edmunds
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003429:Cross Reactions / Q000276:immunology*; D014943:Global Health; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology / Q000276:immunology* / Q000821:virology; D008875:Middle Aged; D012307:Risk Factors; D055815:Young Adult
keywords: mathematical modelling