SUMMARYIn 2014, the Food and Drug Administration approved a new human papillomavirus 9-valent
vaccine (9vHPV), targeting nine HPV types: HPV types 6, 11, 16, and 18, which are also
targeted by the quadrivalent HPV vaccine (qHPV), plus five additional high cancer risk HPV
types (HPV types 31, 33, 45, 52, and 58). The aim of the current study was to
systematically retrieve, qualitatively and quantitatively pool, as well as critically
appraise all available evidence on 9vHPV from randomized controlled trials (RCTs). We
conducted a systematic review of the literature on 9vHPV efficacy, immunogenicity and
safety, as well as a systematic search of registered, completed, and ongoing RCTs. We
retrieved and screened 227 records for eligibility. A total of 10 publications reported on
RCTs’ results on 9vHPV and were included in the review. Sixteen RCTs on 9vHPV have been
registered on RCT registries. There is evidence that 9vHPV generated a response to HPV
types 6, 11, 16 and 18 that was non-inferior to qHPV. Vaccine efficacy against five
additional HPV type-related diseases was directly assessed on females aged 16–26 years
(risk reduction against high-grade cervical, vulvar or vaginal disease = 96·7%, 95% CI
80·9%–99·8%). Bridging efficacy was demonstrated for males and females aged 9–15 years and
males aged 16–26 years (the lower bound of the 95% CIs of both the geometric mean titer
ratio and difference in seroconversion rates meeting the criteria for non-inferiority for
all HPV types). Overall, 9vHPV has been proved to be safe and well tolerated. Other RCTs
addressed: 9vHPV co-administration with other vaccines, 9vHPV administration in subjects
that previously received qHPV and 9vHPV efficacy in regimens containing fewer than three
doses. The inclusion of additional HPV types in 9vHPV offers great potential to expand
protection against HPV infection. However, the impact of 9vHPV on reducing the global
burden of HPV-related disease will greatly depend on vaccine uptake, coverage,
availability, and affordability.