Patchy geographical coverage of dog vaccinations is a key barrier for rabies elimination
Published: 14 May 2025
Dog vaccination programmes are a highly effective way to control and, ultimately, eliminate rabies, however new research has shown just how detrimental geographical gaps in vaccine coverage can be for virus control
Dog vaccination programmes are a highly effective way to control and, ultimately, eliminate rabies, however new research has shown just how detrimental geographical gaps in vaccine coverage can be for virus control.
The new research, led by the University of Glasgow in collaboration with the Ifakara Health Institute, Tanzania, and Global Animal Health Tanzania, examined two decades of dog vaccination data from the Serengeti district, from 2002 to 2022. The study is published in PLOS Biology.
Through analysis of detailed local data researchers were able to show where vaccination programmes had been effective, and, importantly, why some dog-mediated rabies outbreaks had occurred.
Researchers found that when district-wide dog vaccination was both routine, and comprehensive in its geographical coverage, rabies outbreaks in humans were few or none. However, rabies cases in humans did begin to occur when some areas, such as clusters of villages, remained unvaccinated for more than two years.
The study findings show that sustained control of rabies in Tanzania will require scaled-up dog vaccination efforts, focused on uniform coverage across a wide area, as frequent dog movements mean that neighbouring unvaccinated areas are a persistent source of rabies cases in vaccinated areas.
Dr Elaine Ferguson, corresponding author of the study, from the University of Glasgow’s School of Biodiversity, One Health & Veterinary Medicine, said: “Unfortunately rabies circulates so widely that even if you protect some villages for a period, it's likely that disease will return, spreading from domestic dogs in nearby villages that are unvaccinated. That means dog vaccination needs to be a concerted and coordinated effort.”
Despite effective post-exposure human vaccines being available, dog-mediated rabies is still responsible for tens of thousands of human deaths every year. These are predominantly in Africa and Asia where rural communities are most at-risk of both bites from infected dogs and being unable to secure post-bite vaccination on time. Of those who die of the disease, the WHO estimate four in ten are children.
In 2015 the Zero by 2030 goal was announced, with the aim of eradicating dog-mediated rabies deaths by 2030. Scaling up mass dog vaccination is a key component of the Zero by 30 goal. Indeed, dog vaccination was integral to the elimination of rabies from Japan in 1957 and is still maintained there as a safeguard against reintroductions. Mass dog vaccination was also central to reducing dog-mediated rabies by more than 95% between 1980 and 2010 in Latin America and the Caribbean, with Mexico now free from dog-mediated human rabies.
Despite huge strides in the Americas, mass dog vaccination has not yet successfully been implemented at scale across Africa and Asia, with rural areas in the Serengeti district of Tanzania still at risk of outbreaks of the fatal disease.
Dr Ahmed Lugelo, co-author of the study, from the Ifakara Health Institute, said: “The challenge in Africa is that dog vaccination has not been prioritized. We hope that our work is helping to change that, by showing just how effective dog vaccination can be and the importance of scaling up efforts across communities.”
The study, ‘Improved effectiveness of vaccination campaigns against rabies by reducing spatial heterogeneity in coverage’ is published in PLOS Biology.
Enquiries: ali.howard@glasgow.ac.uk or elizabeth.mcmeekin@glasgow.ac.uk
First published: 14 May 2025