Sustainability of neutralising antibodies induced by bivalent or quadrivalent HPV vaccines and correlation with efficacy: a combined follow-up analysis of data from two randomised, double-blind, multicentre, phase 3 trials
Study of antibody (AB) responses in Finnish recipients of bi-& quadrivalent vaccine notes significant differences in immunogenicity of the 2 vaccines are in line with differences in their cross-protective efficacy. Protective AB levels were detected up to 12 yrs after vaccination
Source:
The Lancet Infectious Diseases
SPS commentary:
The researchers note significantly higher sustainable seroprevalences for HPV16, 18, 31, 33, 45, 52, and 58 in bivalent vaccine recipients than in quadrivalent vaccine recipients. HPV16, 18, and 31 neutralising antibody concentrations 5–12 years after vaccination in the bivalent vaccine recipients were significantly higher than in the quadrivalent vaccine recipients.
According to a commentary, this follow-up analysis of data from the Finnish cohorts of two international, randomised, double-blind, phase 3 trials of HPV vaccines, PATRICIA (bivalent, HPV16 and 18) and FUTURE II (quadrivalent, HPV6, 11, 16, and 18) provides the first evidence linking efficacy with both neutralising and cross-neutralising antibody titres measured by a high-throughput pseudovirion-based assay for direct comparison of both vaccines. It suggests the findings showed that the bivalent vaccine is the only HPV vaccine that comes close to meeting the WHO model assumptions of efficacy and longevity needed for cervical cancer elimination. It adds that although this analysis does not identify the surrogate neutralising antibody titres needed for efficacy, it does provide rigorous evidence that modelling assumptions of lifelong protection are not supported for the quadrivalent HPV vaccine.
There are currently three different HPV vaccine products licensed in the UK. Cervarix® contains Virus-like particles (VLPs) for two HPV types (16 and 18 – bivalent vaccine), Gardasil® contains VLPs for four HPV types (6, 11, 16 and 18 – quadrivalent vaccine) and Gardasil®9 contains VLPs for nine HPV types (6, 11, 16, 18, 31, 33, 45, 52 and 58 – nine valent vaccine).