Dog vaccination more cost-effective than routine child PrEP for rabies in Kerala: study

Intensifying dog vaccination and ensuring that people bitten by dogs receive timely, complete rabies post-exposure prophylaxis (PEP) would save far more lives in Kerala than routinely vaccinating children against rabies before exposure, a new modelling study on the cost-effectiveness of rabies interventions has found.

Published in The Lancet Regional Health – Southeast Asia, the study estimates that routine childhood pre-exposure prophylaxis (PrEP) would prevent only about 10 additional deaths over a decade, while adding an estimated $10.5 million to $36.5 million in healthcare costs.

By contrast, comprehensive dog vaccination combined with better post-bite treatment and efforts to close gaps in PEP could reduce rabies deaths by 83% relative to the current strategy. Scaling up vaccination of both owned and free-roaming dogs to 70% coverage could bring human rabies deaths in Kerala to zero within three years, according to the model.

The research was led by the University of Glasgow along with researchers from the Directorate of Medical Education, Kerala University of Health Sciences, the School of Public Health, the Directorates of Health and Animal Husbandry in Kerala, and the London School of Economics and Political Science.

A state with strong PEP access

Rabies prevention is already among Kerala's most intensive public health efforts. More than 9,00,000 people receive free treatment each year after animal bites, and the State's PEP completion rate exceeds 90%. Yet human rabies deaths continue, with 33 reported in 2025, including among children.

The findings add a new dimension to the debate over whether Kerala should introduce routine PrEP for children. Paediatricians and several public health experts have advocated childhood PrEP, arguing that children are especially vulnerable to severe bites, including injuries to the face and hands, which can prove fatal despite post-exposure treatment.

The study does not rule out PrEP. It argues instead that PrEP may be better suited to specific high-risk groups who struggle to reach healthcare facilities quickly after exposure, including some geographically dispersed tribal communities. Given Kerala's relatively strong access to PEP, universal childhood PrEP may yield little additional mortality reduction for the resources required, whereas improved dog vaccination and better wound management and timely PEP may deliver greater population-level gains.

Cost-effectiveness and the canine reservoir

"The study is a comparison of the cost effectiveness of PrEP against other interventions as a population-level strategy to reduce rabies. It points out that, as a public health strategy, investing in dog vaccination is more cost effective because it stops virus transmission in the community, and takes us closer to rabies elimination," said Zinia T. Nujum of the School of Public Health, KUHS, who led the research in Kerala.

Martha Luka, a researcher at the University of Glasgow's School of Biodiversity, One Health & Veterinary Medicine and lead author, said PrEP for children is unlikely to be the best use of public health resources in Kerala, where access to post-bite vaccination and completion of the regimen are already high.

Canines are the reservoir of the rabies virus and account for 70% of cases. Vaccinating the dog population interrupts transmission before people are exposed, whereas PrEP mainly protects vaccinated individuals while the wider risk remains.

The researchers modelled 12 different combinations of dog vaccination, post-bite treatment and PrEP over a 10-year period from 2026 to 2035. Their sensitivity analysis underlines the importance of improving access to PEP: raising the proportion of bite victims who seek medical care from 70% to 95% could prevent more than 1,100 additional deaths — over 20 times the mortality reduction achievable even with maximum PrEP coverage in the model.

Domestic dogs and data gaps

The researchers also found that increasing vaccination coverage among domestic dogs alone could produce substantial health gains. "About 70-80% of dog-bite cases in the State are due to domestic dogs. Mandatory licensing and vaccination of domestic dogs can help improve coverage. We could focus on completing domestic dog vaccination and then move on to vaccinating strays," Dr. Nujum said.

She noted, however, that Kerala's free-roaming dog population could be at least five times the official estimate, highlighting the need for better data to plan vaccination programmes. The researchers argue that the State's priority should be a sustained One Health-based dog vaccination programme targeting at least 70% coverage, involving local bodies, the Animal Husbandry and Health departments, veterinary teams, NGOs and communities.