Evaluating vaccination strategies to control foot-and-mouth disease: a country comparison study

Abstract

Vaccination is increasingly being recognised as a potential tool to supplement 'stamping out' for controlling foot-and-mouth disease (FMD) outbreaks in non-endemic countries. Infectious disease simulation models provide the opportunity to determine how vaccination might be used in the face of an FMD outbreak. Previously, consistent relative benefits of specific vaccination strategies across different FMD simulation modelling platforms have been demonstrated, using a UK FMD outbreak scenario. We extended this work to assess the relative effectiveness of selected vaccination strategies in five countries: Australia, New Zealand, the USA, the UK and Canada. A comparable, but not identical, FMD outbreak scenario was developed for each country with initial seeding of Pan Asia type O FMD virus into an area with a relatively high density of livestock farms. A series of vaccination strategies (in addition to stamping out (SO)) were selected to evaluate key areas of interest from a disease response perspective, including timing of vaccination, species considerations (e.g. vaccination of only those farms with cattle), risk area vaccination and resources available for vaccination. The study found that vaccination used with SO was effective in reducing epidemic size and duration in a severe outbreak situation. Early vaccination and unconstrained resources for vaccination consistently outperformed other strategies. Vaccination of only those farms with cattle produced comparable results, with some countries demonstrating that this could be as effective as all species vaccination. Restriction of vaccination to higher risk areas was less effective than other strategies. This study demonstrates consistency in the relative effectiveness of selected vaccination strategies under different outbreak start up conditions conditional on the assumption that each of the simulation models provide a realistic estimation of FMD virus spread. Preferred outbreak management approaches must however balance the principles identified in this study, working to clearly defined outbreak management objectives, while having a good understanding of logistic requirements and the socio-economic implications of different control measures.

The Carrier Conundrum; A Review of Recent Advances and Persistent Gaps Regarding the Carrier State of Foot-and-Mouth Disease Virus

“…Specifically, as seen within the past decade in South Korea, a strict approach of stamping out to maintain freedom from FMD without vaccination may not be feasible when the disease pressure is overwhelming [6,[154][155][156][157][158]. Additionally, when indirect costs associated with FMD outbreaks, such as job losses within the livestock sector, and losses associated with reduced tourism are accounted for, the estimated financial benefits of vaccination often increase [159][160][161].…”

Post-outbreak surveillance strategies to support proof of freedom from foot-and-mouth disease

“…Vaccination may help suppress the spread of infection (Pluimers et al, 2002) and reduce the need for large-scale culling of at-risk animals (Paton et al, 2006). Epidemiological models can help inform when/where/how suppressive vaccination might best be deployed (Bates et al, 2003; Tildesley et al, 2006; Backer et al, 2012a; Tildesley et al, 2012; Boklund et al, 2013; Porphyre et al, 2013; Hayama et al, 2013; Durr et al, 2014; Rawdon et al, 2018; Marschik et al, 2020), and how constraints on vaccine supply and/or response personnel might impact the effectiveness of control (Abdalla et al, 2005; Roche et al, 2014).…”

Informing adaptive management strategies: Evaluating a mechanism to predict the likely qualitative size of foot‐and‐mouth disease outbreaks in New Zealand using data available in the early response phase of simulated outbreaks

“…This may include whether vaccination should be adopted as an additional response measure. Various studies have indicated that emergency vaccination, if implemented early for large FMD outbreaks, benefits earlier control (Rawdon et al, 2018;Roche et al, 2015;Sanson et al, 2014Sanson et al, , 2017. Vaccination, however, showed minimal effect during small outbreaks (Dürr et al, 2014) and could result in unnecessary competition for resources which are already strained.…”