What once seemed far in the future is now a reality: the human papillomavirus (HPV) vaccine. The quadrivalent vaccine (Gardasil) that prevents the development of lesions caused by HPV types 6, 11, 16, and 18 was approved last June by the US Food and Drug Administration (FDA) for clinical use in females 9 to 26 years old. Shortly after its approval, the Advisory Committee on Immunization Practices (ACIP) issued guidelines on who should be vaccinated.
In light of these developments, OBG Management invited Dr. Tom Wright to convene an expert panel to discuss the ACIP recommendations and ways of introducing the vaccine into practice.
“Vaccination can reduce the disease burden—even in a woman who has had multiple sexual partners”—Barbara S. Levy, MD
“Both the ACIP and ACOG suggest that we encourage ‘catch-up’ vaccination of sexually active women through 26 years”—Thomas C. Wright, MD
“Young people should not have to sneak around to get protection”—Mark DeFrancesco, MD, MBA
“The HPV vaccine is an ObGyn vaccine, and we should embrace it with vigor”—Stanley Gall, MD
“Even if we reach all at-risk young women with our vaccine program, they will still be at risk for infection with other high-risk HPV types”—Barbara S. Levy, MD
ACIP recommends vaccination at age 11 or 12
WRIGHT: Dr. DeFrancesco, would you review the ACIP recommendations for us?
DeFRANCESCO: Shortly after the FDA approved Gardasil, the quadrivalent vaccine (Merck, Whitehouse Station, NJ), the ACIP recommended routine vaccination with 3 doses for girls aged 11 or 12 years, but noted that vaccination is also acceptable for girls as young as 9 at the discretion of the physician or health-care provider. The new 2006–2007 Recommended Adult Immunization Schedule states that the HPV vaccine is “recommended for all women aged ≤26 years of age” (available at www.cdc.gov/nip/recs/adult-schedule).
Ideally, the vaccine should be given before the onset of sexual activity (ie, before a woman is exposed to the virus), but sexually active girls and women through 26 years should still be vaccinated, as they are not likely to have been exposed to all 4 HPV types covered by the vaccine.
ACOG recommendations mirror those of ACIP
WRIGHT: Dr. Gall, are ACOG’s recommendations similar to the ACIP’s?
GALL: Yes. They mirror those of the ACIP, as they recommend that:
Should sexually active women be vaccinated?
WRIGHT: Both the ACIP and ACOG suggest that we encourage “catch-up” vaccination of sexually active women through 26 years. However, many experts disagree, arguing that vaccination of this population may not be worth the effort.
Dr. Gall, why does ACOG recommend that sexually active women get vaccinated?
GALL: Data from the Merck Phase III trials indicate that only 25% of women at age 23 are either serologically or DNA positive for 1 of the 4 HPV types included in the quadrivalent vaccine and that only 0.1% of women are positive for all 4 vaccine HPV types. Data on HPV 16 from the National Health and Nutrition Examination Surveys (NHANES), conducted by the Centers for Disease Control and Prevention (CDC), are in line with this estimate. It is pretty clear that most sexually active women aged 26 or younger will benefit from vaccination.
Vaccine may benefit even women with high-risk sexual practices
WRIGHT: OK, Dr. Levy, you heard Dr. Gall say we should vaccinate sexually active women. Are you convinced? What are you going to tell a 24-year-old single woman who has had 12 lifetime sexual partners?
LEVY: I would tell her that she is extremely likely to have been infected with 1 or more HPV strains—but unlikely to have been exposed to all 4 types present in the vaccine. I would also explain that the vaccine is almost 100% effective at preventing genital warts caused by HPV 6 and 11 and will prevent both infections and lesions with HPV types 16 and/or 18 if the patient has not been exposed to them.
The benefit for this 24-year-old may not be as great as it is for our primary target population of preteens not yet exposed to HPV, but vaccination can reduce the disease burden—even in a woman who has had multiple sexual partners.
If this patient has already had genital warts and an abnormal Pap smear, or is positive for high-risk HPV DNA, the benefit would be even lower. Ultimately, she will have to decide whether the cost is worth the lessened benefit in her situation.
Lessons learned from the hepatitis B experience
WRIGHT: One of the things we learned 20 years ago when we introduced the hepatitis B vaccine is that limiting vaccination to groups expected to gain the most benefit doesn’t work very well. With hepatitis B, we initially targeted only high-risk groups such as intravenous drug users, men who have sex with men, and health-care workers—but this strategy didn’t reduce the rate of hepatitis to the extent expected. Once we recommended universal vaccination of the general population, however, a rapid reduction in hepatitis B occurred.