Rabies kills an estimated 59,000 people each year, mainly in Africa and Asia, with children at greatest risk. Although effective vaccines exist, they typically require two or more clinic visits, making them difficult to deliver in many low-resource settings.
The new vaccine, ChAdOx2 RabG, is designed to be given in a single visit. In the trial, conducted in Tanzania, researchers tested its safety and the immune response it created. 63 adults and 111 children aged 2-6 years received either the new vaccine or a currently licensed rabies vaccine for comparison.
The researchers found that the new vaccine triggered much stronger immune responses than the currently available rabies vaccines. Antibody levels in adults were around five times higher than those seen with a single dose of the current rabies vaccines after a year, and in children they were more than eight times higher.
In children, the new, single-dose vaccine also outperformed a standard two-dose regimen of current vaccine recommended by the World Health Organisation. Nearly all children who received the new vaccine maintained antibody levels above the threshold considered protective against rabies one year after vaccination.
"Rabies is entirely preventable, yet it still causes tens of thousands of deaths each year, mostly among children," said Professor Sandy Douglas of the Jenner Institute, Nuffield Department of Medicine at the University of Oxford, the developer of the vaccine and the study’s senior author. "What makes this especially tragic is that existing vaccines work well, but they are difficult to deliver in the places where they are most needed.
"Our findings suggest that a single-dose vaccine could offer a practical and affordable way to protect vulnerable populations, particularly in rural and low-resource settings."
Read the full story on the Nuffield Department of Medicine website.