Guidelines for the human papillomavirus (HPV) vaccine include recommendations on which populations of individuals should receive either the 2-dose or 3-dose regimen.
It is now easier to meet human papillomavirus (HPV) vaccine recommendations for all patients, according to a report from the Advisory Committee on Immunization Practices (ACIP).
Although three doses of HPV vaccine are still advised for females and males who have their first dose between the ages of 15 and 26, as well as for those who are immunocompromised, girls and boys who start the HPV vaccine series between the ages of 9 and 14 need only two doses, lead report author Elissa Meites, MD, MPH, a medical epidemiologist at the Centers for Disease Control and Prevention in Atlanta, Georgia, and colleagues wrote in the journal, American Journal of Transplantation, online February 27, 2017.
"Through 10 years of follow-up from clinical trials, no evidence of waning protection after a 3-dose series of HPV vaccine has been found. Because antibody kinetics are similar with 2-dose and 3-dose series, duration of protection is also expected to be long-lasting after a 2-dose series," the authors wrote.
"HPV infection causes cervical, vaginal, and vulvar cancers in women; penile cancers in men; and oropharyngeal and anal cancers as well as genital warts in both men and women…HPV vaccines are highly effective and safe, and a powerful prevention tool for reducing HPV infections and HPV-associated cancers. Based on the available immunogenicity evidence, a 2-dose schedule (at 0, and 6—12 months following) will have efficacy equivalent to a 3-dose schedule (at 0, 1–2, and 6 months) if the HPV vaccination series is initiated before the 15th birthday," the authors recommend.
As of late 2016, only the 9-valent HPV (9vHPV) vaccine (licensed by Merck and Co, Inc., Whitehouse Station, New Jersey) is being distributed in the United States.
The authors conducted a systematic review of studies that reported primary data on important or critical health outcomes related to HPV vaccination after two doses in 9- through 14-year-old girls and boys.
In the 9vHPV clinical trial that led to FDA approval of a 2-dose series, 9- through 14-year-old girls and boys who received two vaccine doses were compared with 16- through 26-year-old females who received three doses. By 4 weeks after the last dose, 97.9% or more of the 1377 study participants seroconverted to all nine vaccine-preventable HPV types. Also, geometric mean titers (GMTs) were significantly higher for all 9vHPV types in the younger group. Six other studies found similar results for the 4vHPV and 2vHPV vaccines.
The ACIP Work Group reviewed the evidence and the voting ACIP members unanimously approved the updated recommendations in October 2016.
ACIP now recommends that children receive their first HPV vaccination when they are 11 or 12 years of age, but they may begin at the age of 9. ACIP also advises vaccination for females through age 26 and for males through age 21 if they were not adequately vaccinated previously, adding that males ages 22 through 26 may be vaccinated.
For individuals receiving their first shot before their 15th birthday, the schedule is two doses, with the second dose given 6 to 12 months after the first.
For those receiving their first shot on or after their 15th birthday, the schedule is three doses, with the second dose given 1 to 2 months after the first dose, and the third dose given 6 months after the first.
ACIP advises that children with a history of sexual abuse or assault be routinely vaccinated starting at 9 years of age. Men who have sex with men should receive the routine male HPV shots and should be vaccinated through age 26 if they were not sufficiently vaccinated in the past. Individuals who are transgender should receive the routine adolescent HPV shots and be vaccinated through age 26 if they were not sufficiently vaccinated in the past.
For 9- through 26-year-old females and males who have primary or secondary immunocompromising conditions that might reduce cell-mediated or humoral immunity, ACIP advises the 3-dose schedule.
In the results of a survey of United States sexually transmitted disease (STD) clinics that was presented September 23, 2016 at the Centers for Disease Control and Prevention (CDC) STD Prevention Conference in Atlanta, Georgia, Dr. Meites wrote in her abstract, "By early 2015, in a geographically diverse group of 78 STD clinics, most offered nationally-recommended HPV vaccination, but financing remained an important barrier."
"Increasing participation in federally funded programs such as Vaccines for Children might reduce such barriers, at least in part. Further research could identify additional strategies for STD clinics to increase provision of HPV vaccination according to national guidelines," she proposed.
The 2-dose series could be more cost-effective and help ensure that more people are adequately vaccinated.
According to results of another study presented the same day at the conference, health care providers may be missing opportunities to vaccinate adolescents against HPV.
Kelly Jamison, MPH, a research scientist and analyst at the Bureau of Sexually Transmitted Disease Control of the New York City Department of Health and Mental Hygiene, and her colleagues reviewed the electronic medical record (EMR) data of adolescents attending STD clinics in New York City between 2010 and 2013 and the Citywide Immunization Registry (CIR) of all immunization records for city residents 18 years of age or younger.
The authors cross-matched the EMR with the CIR to identify all immunizations administered by any New York City provider. They included clinic patients who were eligible for the HPV vaccine and had at least one immunization event between 11 and 18 years of age recorded in the CIR.
Among 13- to-18-year-olds attending New York STD clinics, only around 46% of females and 12% of males received the recommended 3-dose series of HPV vaccinations over six months, lead author Ms. Jamison said in her presentation.
"Although the vaccine has been available for nearly a decade, HPV vaccine uptake has been slow, with estimated national three-dose coverage of adolescent females about 40% and adolescent males about 22%," she added.
"STD clinic patients are a group at increased risk for HPV acquisition; they also remain under-vaccinated," she noted.
The researchers think that their estimates are conservative. "We used registry data, but most likely, these patients actually visited the clinic more times than we were able to capture," Ms. Jamison told Contagion® in an interview.
"New York State has dropped the requirement that adolescents have parental consent to receive an HPV vaccination," Ms. Jamison said in the interview. "So far, we've provided at least one dose to over 800 patients."
Lorraine L. Janeczko, MPH, is a medical science writer who creates news, continuing medical education and feature content in a wide range of specialties for clinicians, researchers and other readers. She has completed a Master of Public Health degree through the Department of Epidemiology of the Johns Hopkins Bloomberg School of Public Health and a Dana Postdoctoral Fellowship in Preventive Public Health Ophthalmology from the Wilmer Eye Institute, the Johns Hopkins University School of Medicine and the Bloomberg School.
DISCLOSURES: The authors did not report any conflicts of interest with the study.