More Research Needed To Understand Levels Of Protection In Fractionated vs. Full-Dose Yellow Fever Vaccines
The Lancet: Yellow fever: a major threat to public health
“…Due to a global shortage of the [yellow fever] vaccine, in outbreak emergencies WHO recommends fractional dosing to protect more people by using less antigen in each dose. … For routine immunization, the standard full dose, recommended by WHO since 2013, is thought to confer lifelong protection, although supporting evidence for this view is not strong. … As a zoonotic disease, with a reservoir in non-human primates, it is unlikely that yellow fever will be eradicated. However, epidemics can be prevented if populations are protected by routine immunization and if mass vaccination campaigns are implemented quickly in response to an outbreak. A coalition of partners led by WHO, UNICEF, and Gavi, the Vaccine Alliance, aims to eliminate yellow fever epidemics worldwide by 2026. To achieve this goal, there is an urgent need for research to clarify the duration of protective levels of immunity provided by fractionated and full-dose yellow fever vaccines to support development of effective vaccination programs” (2/3).