Uptake and spread of infectious laryngotracheitis vaccine virus within meat chicken flocks following drinking water vaccination.

•Uptake of ILT vaccine from drinking water administration is highly variable.•Field vaccination success therefore relies on bird to bird spread of vaccine.•Uptake of vaccine from water by <17% of birds may leave many susceptible birds by time of challenge.•Effects of administration practices need to be further studied in relation to vaccine uptake.