Yellow Fever and Pneumococcal Conjugate Vaccines Mix Well

When international travelers plan to visit a country that requires proof of yellow fever (YF) vaccination, other vaccines may be administered at travel clinics to protect the person from disease.

Because booster doses of pneumococcal conjugate vaccine (PCV) may be given at a similar time to yellow fever vaccine, researchers believed it essential to assess the immune response to YF when co-administered with PCV.

An early release of a study published in the journal Vaccine (Volume 47), February 15, 2025, showed no evidence of the non-inferiority of the seroresponse to the YF vaccine when co-administered with PCV13.

The levels of YF NA attaining seroprotection (NT ≥1:8) were high (85%+) in all groups. PCV13, co-administered with the YF vaccine, does not affect the seroresponse to the YF vaccine.

In 2024, the World Health Organization (WHO) confirmed the yellow fever virus had become endemic in tropical areas of Africa and countries in the Region of the Americas. And 194 WHO member countries have introduced the YF vaccine into their routine Essential Programme on Immunization programs.

For example, Costa Rica recently expanded its proof of vaccination requirements.

In this Central American country, the YF vaccine is given as a single dose, generally at 9 months of age. It is often co-administered with the measles/rubella vaccine and the oral polio vaccine.

While some studies have shown no decrease in YF vaccine seroresponse when co-administered with measles/rubella vaccines, other studies have reported a decreased seroresponse against YF vaccines.

This research was supported by the Bill & Melinda Gates Foundation [grant number OPP1138798]. 

As of January 16, 2025, yellow fever vaccinations with Sanofi Pasteur's YF-VAX® are offered at travel clinics and pharmacies in the United States. Additionally, several next-generation yellow fever vaccine candidates are conducting clinical trials.