A promising new weapon has emerged in the global fight against yellow fever. This virus, which spreads to humans through the bites of infected mosquitoes, causes symptoms ranging from mild fever and pain to severe liver disease.
According to a recent study, it has been found that a new yellow fever vaccine called VYF by Sanofi works similarly to the current licensed vaccine, YF-Vax. Despite the existence of safe vaccines, yellow fever causes 29,000 to 60,000 deaths annually.
Previous serious outbreaks in Central Africa and Brazil had exhausted global emergency supplies, forcing the use of fractional doses. Since there is no antiviral treatment for yellow fever, vaccination is the only effective prevention. The VYF vaccine was developed by Sanofi; Unlike traditional vaccines, VYF is grown in Vero cells. This new method allows for higher yields and more efficient production, directly addressing the global shortage of supplements. A total of 485 healthy adults (aged 18–60 years) participated in the clinical trials.
This randomized, observer-blind study compared the new VYF vaccine with the established VF-Vax. A total of 329 participants received VFF, while 156 received VF-Vax. Key results showed that 99.7% of the VYF group developed protective antibodies within 28 days, almost identical to the 99.4% success rate of the YF-Vax group.
In both groups, antibody levels peaked on day 29 and declined at similar rates over the next year. No major safety issues were identified. Side effects were mild, and no participants withdrew due to adverse reactions. Once final approved, the VYF will provide a scalable, high-volume tool to prevent future vaccine shortages and control global outbreaks.
