Experts are weighing one-dose HPV vaccination after a study in Costa Rica of over 20,000 girls found one shot gave about 97% protection against cervical cancer, similar to two doses. They still advise two doses; one-dose evidence for boys and other cancers is limited.
Robert F. Kennedy Jr. ordered a one-dose recommendation in January as part of a unilateral reduction to the childhood vaccination schedule, but a federal judge blocked the change. The American Academy of Pediatrics is considering its own guidance; a CDC advisory committee work group exploring a revision was interrupted after Kennedy dismissed the committee members.
About 63% of U.S. teens have received both HPV doses, a rate flat for four years and below rates for some other adolescent vaccines, according to a recent CDC report. The report said the lower uptake is partly because most states do not require HPV shots for school attendance. Studies in multiple countries have recorded declines in HPV infections, genital warts and precancerous cervical lesions; an April JAMA Oncology study found vaccinated males nearly 50% less likely to develop cancers of the head and neck, esophagus, anus or penis.
