Assessing the impact of a novel strategy for delivering animal health interventions to smallholder farmers.

•A strategy for sensitising farmers and delivering Newcastle disease vaccines to smallholders in India, Nepal and Tanzania.•16–24 months after implementation of the programme the levels of adoption of vaccines were greater than 75% in all areas.•There was a two-fold increase in flock sizes.•There was an increase in the frequency of consumption of chicken meat and an increase in sales of chickens.