An update on one-dose HPV vaccine studies, immunobridging and humoral immune responses – A meeting report

Highlights

• •

  Clinical trial subjects followed up for up to 10 years after receiving one dose HPV vaccine show stable antibody levels.

• •

  One dose vaccine efficacy against vaccine-type incidence persistent infection in India and Costa Rica cohorts is > 80%.

• •

  Further study is needed for one-dose HPV vaccination in HIV + individuals, but it shouldn’t delay general adoption.

• •

  HPV vaccine immune response plateaus at 24 months. Studies with 24 + months follow-up are needed for accurate comparison.

• •

  Anchored International Standards for 9 HPV vaccine genotypes will facilitate immunogenicity reporting and assay optimisation.

Abstract

The 12th HPV Prevention and Control meeting was held on June 2–3, 2022, in Antwerp, Belgium. This technical meeting focused on several topics. This report summarises the discussions and lessons learned on two topics: an update on one-dose HPV vaccination studies and humoral immune responses upon HPV vaccination. Long-term follow-up studies from Costa Rica (eleven years) and India (ten years) report stable levels of antibodies after a single HPV vaccination. High vaccine effectiveness against incident persistent HPV 16/18 infection was seen in India (95.4%, 85.0–99.9) ten years postvaccination and in Kenya (97.5%, 81.7–99.7) eighteen months postvaccination, an important observation in a setting with a higher HPV prevalence. The potential impact of HPV vaccination using a one-dose schedule in India was modelled and showed that implementation of one-dose schedule can contribute towards achieving WHO Cervical Cancer elimination goals. These data support the WHO SAGE recommendations for adopting a one-dose schedule for females aged 9–20 years. Immunobridging studies were discussed during the meeting. General agreement was reached that when thoughtfully applied, they can support and accelerate the expanded use of HPV vaccine with new vaccine schedules, age cohorts, or vaccine formulations. Internationally standardised measurements of HPV immune responses important for the progress of HPV vaccinology field. Humoral immune responses upon HPV vaccination plateau at 24 months regardless of number of doses, therefore, data should be analysed after at least 24 months of follow-up to bridge studies accurately.