Seroconversion and persistence of neutralizing antibody response after yellow fever vaccination in patients with perinatally acquired HIV infection

Objective(s):To describe the dynamics of neutralizing antibody (NAbs) response after yellow fever (YF) vaccine in young adults and adolescents with perinatally acquired HIV (pHIV).Design:A retrospective cross-sectional study at three time points around YF vaccination and a matched case-control comparison of NAbs titers several years after YF vaccination.Methods:We selected patients who had both documented YF vaccination and perinatally acquired HIV (n = 46). The NAbs titers were measured in plasma samples from the following three time points: during the two years before (TP0), within the year after (TP1) and >1 year after (TP2) administration of the YF vaccine. The impact of perinatal infection was assessed by comparing pHIV YF vaccinees with 44 controls infected with HIV during adulthood.Results:The median time between the YF vaccine and TP1 and TP2 was 123 days and 7.3 years, respectively. After YF vaccination, 85% of vaccinees experienced seroconversion. The proportion of pHIV patients with NAbs above the protective threshold was stable between TP1 and TP2 (91% and 86%, respectively) but levels of NAbs decreased significantly between TP1 and TP2 (P = 0.0122). The case-control analysis found slightly higher geometrical mean titers (GMT) in pHIV than patients infected during adulthood.Conclusions:Patients with pHIV showed high seroconversion rate and NAbs persistence at levels above the protective threshold after first YF vaccination. However, a decline in antibody levels over time suggests that at least one revaccination may be necessary to maintain circulating antibodies, contrary to recommendations for the general population.