title: Current status of HBV vaccine escape variants--a mathematical model of their epidemiology.
abstract: We present a deterministic model of the possible emergence of a vaccine escape variant of hepatitis B virus (HBV). The model identifies the key unknowns determining this process: the protection afforded by the current vaccines against particular HBV variants; the infectiousness of these variants; and the current prevalence of individuals infectious with the variants (each factor relative to wild-type). By making pessimistic assumptions about these unknowns we show that even a highly infectious variant, under a vaccine programme that affords no protection against the variant, would still take decades to emerge. Thus the current low prevalence of variants is not evidence for the cross-reactivity of the current vaccines or for a lack of infectiousness in the variants. As any vaccine failure will be inapparent for decades it may be sensible to recommend vaccine modifications now rather than later.
authors.affiliation: Wellcome Trust Centre for the Epidemiology of Infectious Disease, University of Oxford, UK.
authors.forename: J N
authors.initials: JN
authors.lastname: Wilson
authors.forename: D J
authors.initials: DJ
authors.lastname: Nokes
authors.forename: W F
authors.initials: WF
authors.lastname: Carman
mesh_terms: D017325:Hepatitis B Vaccines / Q000276:immunology*; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology*; D019694:Hepatitis B, Chronic / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D008962:Models, Theoretical; D017720:Molecular Epidemiology; D009154:Mutation; D014611:Vaccination
chemical_list: D017325:Hepatitis B Vaccines