Researchers from the National Cancer Institute in collaboration with colleagues in Costa Rica recently determined whether the protective efficacy of one dose of a bivalent human papillomavirus (HPV) vaccine (types 16 and 18) or one dose of a nonavalent vaccine (types 6, 11, 16, 18, 31, 33, 45, 52 and 58) was non-inferior to two doses in girls 12-16 years of age (Kreimer AR, C Porras, D Liu, et al. “Noninferiority of one HPV vaccine dose to two doses.” N Engl J Med. Dec 2025 18;393(24):2421-2433).
A total of 3,000 unvaccinated 12- to 16-year-old girls were randomized to receive one or two doses of a bivalent or nonavalent HPV vaccine. Researchers found that the protective efficacy against HPV infection was about 97% in each of the four groups. The authors concluded that “One dose of either a bivalent or nonavalent HPV vaccine provided protection against HPV16 or HPV18 infection and was not inferior to two doses.”
Prior to June 7, 2025, the HPV vaccine working group of the Advisory Committee on Immunization Practices (ACIP) was poised to discuss the possibility of lessening the number of doses of HPV vaccine for certain groups. At the time, two doses of vaccine were recommended for those less than 15 years of age and three doses for those greater than 15 years of age. The working group was poised to decide whether children could reasonably receive fewer doses. This determination would be based on the degree and duration of protective efficacy. However, after the Secretary of Health and Human Services, Robert F. Kennedy Jr., discharged all 17 members of the ACIP, the HPV vaccine working group, at least temporarily, has been disbanded. For now, the decision on the number of HPV doses is in limbo pending reconstitution of the ACIP voting members and HPV vaccine working group. A group based in Minnesota, called The Vaccine Integrity Project, is also rigorously evaluating the data to inform the best recommendations for use in the U.S.
Contributed by: Paul A. Offit, MD
Researchers from the National Cancer Institute in collaboration with colleagues in Costa Rica recently determined whether the protective efficacy of one dose of a bivalent human papillomavirus (HPV) vaccine (types 16 and 18) or one dose of a nonavalent vaccine (types 6, 11, 16, 18, 31, 33, 45, 52 and 58) was non-inferior to two doses in girls 12-16 years of age (Kreimer AR, C Porras, D Liu, et al. “Noninferiority of one HPV vaccine dose to two doses.” N Engl J Med. Dec 2025 18;393(24):2421-2433).
A total of 3,000 unvaccinated 12- to 16-year-old girls were randomized to receive one or two doses of a bivalent or nonavalent HPV vaccine. Researchers found that the protective efficacy against HPV infection was about 97% in each of the four groups. The authors concluded that “One dose of either a bivalent or nonavalent HPV vaccine provided protection against HPV16 or HPV18 infection and was not inferior to two doses.”
Prior to June 7, 2025, the HPV vaccine working group of the Advisory Committee on Immunization Practices (ACIP) was poised to discuss the possibility of lessening the number of doses of HPV vaccine for certain groups. At the time, two doses of vaccine were recommended for those less than 15 years of age and three doses for those greater than 15 years of age. The working group was poised to decide whether children could reasonably receive fewer doses. This determination would be based on the degree and duration of protective efficacy. However, after the Secretary of Health and Human Services, Robert F. Kennedy Jr., discharged all 17 members of the ACIP, the HPV vaccine working group, at least temporarily, has been disbanded. For now, the decision on the number of HPV doses is in limbo pending reconstitution of the ACIP voting members and HPV vaccine working group. A group based in Minnesota, called The Vaccine Integrity Project, is also rigorously evaluating the data to inform the best recommendations for use in the U.S.
Contributed by: Paul A. Offit, MD