Artist's impression of the rabies virus Source: University of Oxford |
Researchers from the University of Oxford have today reported new findings from a Phase 1 clinical trial studying the immune response and safety of their newly-developed single shot rabies vaccine, ChAdOx2 RabG - with promising results identified.
The RAB001 trial was conducted at the University and is the first time the novel rabies vaccine has been used in human volunteers. The aim of the study was to look at safety and measure immune responses from the vaccine by analyzing levels of rabies neutralizing antibodies – a powerful marker of successful rabies vaccination.
In their findings (published in The Lancet Microbe), the researchers reported that 12 volunteers were recruited into the study in total, with three receiving a low dose, three receiving a medium dose and six receiving a high dose of ChAdOx2 RabG. Strong immune responses against rabies were generated by the vaccine, with all volunteers who received a medium or high dose developing levels of rabies neutralizing antibodies above the World Health Organization protective threshold (0.5 International Units / ml) within two months.
No serious adverse events or safety concerns were reported during the trial. Expected levels of common short-lived vaccine side effects such as soreness at the injection area or feverishness were observed in volunteers, mainly in the medium- and higher-dose groups.
Additionally, the researchers assessed longer term immune responses. Six of the seven middle- and high-dose recipients who returned for an additional follow-up one year after vaccination maintained neutralizing antibody levels above the protective threshold, demonstrating that the immune response from the vaccine persists over time.