Successive vaccination against tick-borne encephalitis and yellow fever

The 17D yellow fever vaccine is highly effective, but it is frequently injected into people with pre-existing cross-immunity, which can affect its immunogenicity. In this study, researchers assessed the impact of pre-existing immunity induced by tick-borne encephalitis vaccine on yellow fever vaccination. A total of 250 individuals were included in the study, followed up 1 month after vaccination, and 22 individuals followed up for 1 year. Previous tick-borne encephalitis vaccination did not appear to affect the early neutralizing response induced by yellow fever vaccination. After vaccination, pre-vaccinated individuals developed large quantities of cross-reactive antibodies.