The human papillomavirus (HPV) vaccine is effective in women up to age 20 who had not received the vaccine at the recommended age of 11 or 12, but it’s unclear whether this is true for women 21 to 26, according to a study conducted at Kaiser Permanente Northern California. Currently, the CDC recommends routine two-dose HPV vaccination for adolescents (11 or 12, or as young as 9), and three doses in females 13 through 26 years and males 13 through 21 who were not previously vaccinated (called catch-up vaccines).
Results of the Kaiser study, which involved 25,000 people, suggest catch-up HPV vaccines effectively reduce cervical cancer risk in women vaccinated by the age of 20, but didn’t confirm protection against cervical cancer in women 21 to 26. HPV vaccination rates are relatively low in the U.S. compared to other developed countries, and fewer than half of American girls 13 to 17 are up-to-date with the vaccine series.
Women in the study who received at least three vaccine doses, with the first dose before the age of 20, had the strongest protection against precancerous changes in the cervix. The researchers found no significant protection against cervical cancer in women who received their first HPV dose after the age of 21 or didn’t receive the full vaccine series.
Sourced from: The Lancet Child & Adolescent Health