Persistence of yellow fever virus-specific neutralizing antibodies after vaccination among US travellers

Abstract

Background: Few studies have assessed the duration of humoral immunity following yellow fever (YF) vaccination in a non-endemic population. We evaluated seropositivity among US resident travellers based on time post-vaccination. Methods: We identified serum samples from US travellers with YF virus-specific plaque reduction neutralization testing (PRNT) performed at CDC from 1988 to 2016. Analyses were conducted to assess the effect of time since vaccination on neutralizing antibody titer counts. Results: Among 234 travellers who had neutralizing antibody testing performed on a specimen obtained ≥1 month after vaccination, 13 received multiple YF vaccinations and 221 had one dose of YF vaccine reported. All 13 who received more than one dose of YF vaccine had a positive PRNT regardless of the amount time since most recent vaccination. Among the 221 travellers with one reported dose of YF vaccine, 155 (70%) were vaccinated within 10 years (range 1 month-9 years) and 66 (30%) were vaccinated ≥10 years (range 10-53 years) prior to serum collection. Among the 155 individuals vaccinated, <10 years prior to serum collection, 146 (94%) had a positive PRNT compared with 82% (54/66) of individuals vaccinated ≥10 years prior to serum collection (P = 0.01). Post-vaccination PRNT titers showed a time-dependent decrease. Individuals with immunocompromising conditions were less likely to have a positive PRNT (77%) compared with those who were not immunocompromised (92%; P = 0.04). Conclusion: Although the percentage of vaccinees with a positive PRNT and antibody titers decreased over time, a single dose of YF vaccine provided long-lasting protection in the majority of US travellers. A booster dose could be considered for certain travellers who are planning travel to a high risk area based on immune competence and time since vaccination.

Longitudinal dynamics of the human B cell response to the yellow fever 17D vaccine

“…S1F). Consistent with prior studies (15,16), serum neutralizing activity against YFV-17D appeared in both donors by day 10 postvaccination and persisted through the course of the study (SI Appendix, Fig. S1 E and G).…”

Serological Protection 5–6 Years Post Vaccination Against Yellow Fever in African Infants Vaccinated in Routine Programmes

“…A more recent report followed up 349 Chinese adults who had received YF vaccine prior to deployment to Africa and reported negligible concentrations 11 years post vaccination ( 12 ). Several other studies have demonstrated similar decline in antibody in adults at varied time points post vaccination ( 9 , 11 , 24 – 26 ). The findings following a fractional dose of YF vaccine in The Netherlands differ from ours with a larger proportion retaining protective concentration but are in keeping with other reports of declining antibody from adults.…”

“…When only one dose had been received however, 94% had protective concentrations if that dose was <10 years from testing. When tested 10 or more years later however, only 82% had protective concentrations ( 11 ). These findings would suggest that even in adults, booster vaccinations may be warranted in certain populations.…”

Limited evolution of the yellow fever virus 17d in a mouse infection model

“…The YFV-17D strain was originally derived from a clinical isolate (Asibi strain) and attenuated by serial passaging in the early 1930s [8,9]. The live-attenuated YFV-17D is considered as one of the most efficient vaccines ever developed with long immunogenicity [10,11]. It induces a vigorous, multi-specific and possibly lifelong lasting protective immunity in >95% of the vaccinees within 10 days after vaccination [12,13].…”