# HPV vaccine dosage recommendation evaluation > Live situation record from CLSTR: https://clstr.news/situations/hpv-vaccine-dosage-recommendation-evaluation > Updated: 2026-09-28T18:25:25.000Z. Sources: 11. Developments: 2. Medical experts are evaluating whether the human papillomavirus (HPV) vaccination schedule can be reduced from two doses to a single dose. This proposal aims to determine if a single dose provides sufficient protection for adolescents, potentially replacing current immunization guidance. Research, including a study from Costa Rica, suggests a single dose may provide approximately 97% protection against cervical cancer in girls, a level comparable to the two-dose regimen. However, specialists note that data remains limited regarding effectiveness for boys and other HPV-related cancer types. Consequently, many experts continue to recommend the two-dose schedule for the time being. In the United States, HPV is linked to approximately 50,000 cancer cases annually and is responsible for about 90% of cervical and anal cancers. While the vaccine is a critical tool for preventing various cancers, adolescent vaccination rates in the U.S. have remained stable at around 63% for the two-dose series, partly due to a lack of school mandates in most states. ## Timeline ### 2026-09-28: HPV vaccine: Single-dose regimen under debate for cancer prevention Medical experts are debating a shift to a single-dose HPV vaccine schedule after studies showed high protection levels, though two doses remain the current standard for comprehensive cancer prevention. 3 sources. https://clstr.news/cluster/hpv-vaccine-single-dose-regimen-under-debate-for-cancer-prevention ### 2026-09-26: HPV vaccine experts consider single-dose recommendation Health experts are considering whether a single dose of the HPV vaccine could replace the current two-dose regimen for adolescents, a move that would significantly shift cancer prevention guidance. 8 sources. https://clstr.news/cluster/hpv-vaccine-experts-consider-single-dose-recommendation --- Cite as: HPV vaccine dosage recommendation evaluation. CLSTR, https://clstr.news/situations/hpv-vaccine-dosage-recommendation-evaluation