In this exploratory investigation, researchers wanted to evaluate the level of HPV types 6/11 antibodies in peripartum maternal blood and cord blood of newborns delivered to mothers who received either a 9-valent HPV (9vHPV) vaccination or a quadrivalent HPV (qHPV) vaccine in a pivotal efficacy study (V503-001, NCT 00543543).
A total of 21 pairs of mother-infants had HPV 6/11 findings that could be analyzed. The competitive Luminex immunoassay was used to test HPV6/11 antibodies. The distribution of infant-to-mother anti-HPV antibody ratios was summarized.
All of the moms and babies tested positive for HPV 6 and HPV 11. The geometric mean titers (GMTs) of anti-HPV 6/11 in peripartum maternal blood and cord blood of infants delivered to research participants were substantially associated. All babies born to seropositive moms were likewise seropositive. The GMT ratios of peripartum maternal blood vs. cord blood in the 9vHPV vaccine group were HPV 6: 1.23 [0.43, 3.49] and HPV 11: 1.29 [0.54, 3.07] in the 9vHPV vaccine group and HPV 6: 1.33 [0.41, 4.29] and HPV 11: 1.19 [0.45, 3.13] in the qHPV vaccine group, respectively.
These findings suggest that antibodies produced by the 9vHPV vaccination pass the placenta and may be effective in the treatment of HPV6/11 infection and associated diseases such as recurrent pulmonary papillomatosis.