In Egypt, efforts to control highly pathogenic H5N1 avian influenza
virus in poultry and in humans have failed despite increased
bio security, quarantine, and vaccination at poultry farms. The ongoing
circulation of HP H5N1 avian influenza in Egypt has caused >100
human infections and remains an unresolved threat to veterinary and
public health.Here,we describe that the failure of commercially available H5
poultry vaccines in Egypt may be caused in part by the passive
transfer of maternal H5N1 antibodies to chicks, inhibiting their immune response to vaccination.We propose that the induction of a protective
immune response to H5N1 is suppressed for an extended
period in young chickens. This issue, among others,must be resolved
and additional steps must be taken before the outbreaks in Egypt can
be controlled.
