Maternal transfer of anti HPV 6 and 11 antibodies upon immunization with the 9-valent HPV vaccine

ABSTRACTBackground: This exploratory analysis was conducted to characterize the level of HPV types 6/11 antibodies in peripartum maternal blood and in cord blood of infants born to women who received 9-valent HPV (9vHPV) vaccine or quadrivalent HPV (qHPV) vaccine in a pivotal efficacy study (V503-001, NCT 00543543).Methods: A total of 21 mother-infant pairs had evaluable HPV 6/11 results available for analysis. HPV6/11 antibodies were assessed using competitive Luminex immunoassay. The distribution of the ratios of infant to mother anti-HPV antibodies (i.e., infant-anti-HPV/mother- anti-HPV) was summarized.Results: All mothers and infants were seropositive to HPV 6 and HPV 11. Anti-HPV 6/11 geometric mean titers (GMTs) in peripartum maternal blood and in cord blood of infant born to study participants were highly correlated. A 100% of infants born to seropositive mothers were also seropositive. The GMT ratios of peripartum maternal blood vs. those in cord blood were HPV 6: 1.23 [0.43, 3.49] and HPV 11: 1....