Assessing the efficacy of vaccination strategies in curbing epidemics of Foot-and-Mouth Disease in The Netherlands.

The 2001 epidemic of Foot- and Mouth Disease (FMD) in the Netherlands has been brought to a halt by a combination of pre-emptive culling, emergency vaccination and depopulation measures in a large area comprising about 1800 farms. After the large Dutch HPAI epidemic in poultry in 2003, public acceptance of intervention strategies based on massive culling has further eroded. Policy makers in the Netherlands are therefore interested in assessing the use of emergency vaccination as a basis for intervention in the future. Here we use spatial transmission models to analyse the transmission potential of FMD between farms in the Netherlands, and to assess the expected efficacy of a set of alternative emergency vaccination strategies in curbing FMD spread. Our results, presented in the form of risk-maps for FMD spread, suggest that ring-culling or ring-vaccination strategies are insufficiently effective to achieve epidemic control in certain important areas in the Netherlands (with high densities of farms). In these areas only area-wide culling and/or vaccination strategies would stand a chance of being effective. On the positive side, our results suggest that in much of the Netherlands outside the high-density areas, standard intervention measures as required by the EU (a movement standstill, bio-security measures and culling of infected farms and dangerous-contact farms) would be sufficient to curb local propagation of the epidemic