A Single Dose of Yellow Fever Vaccine Does Not Offer Lasting Protection to all Children

The World Health Organization (WHO) recommends a single dose of the yellow fever vaccine for individuals aged 9 months or older living in or traveling to areas at risk of disease transmission, but there is a lack of data on its long-term efficacy when administered to infants. José Enrique Mejía, Inserm researcher at Unit 1043 Center for Pathophysiology of Toulouse Purpan and Cristina Domingo from the Robert Koch Institute in Berlin have recently shown that around half of children initially protected by the vaccination at 9 months of age lose that protection within the next 2 to 5 years, due to disappearance of the neutralizing antibodies.