An immunization update

Human papillomavirus, hepatitis B

HPV vaccines are not recommended for use in pregnant women, and although ob.gyns. are not the central players with these vaccines, we still have an important role to play in HPV immunization. We can help backstop pediatricians and facilitate the recommended "catch-up" for females aged 13-26 years who were not immunized at the recommended starting age of 11 or 12 years.

Unfortunately, the three-dose HPV vaccine series was misframed in the United States as a vaccine to prevent a sexually transmitted infection, rather than being framed, as it was in other countries, as a vaccine to prevent cancer. The unintended consequence has been widespread unwillingness of many U.S. parents to vaccinate their young daughters – a phenomenon that has challenged pediatricians and limited uptake of the vaccine.

For ob.gyns., the catch-up role means that many of their patients who are potential candidates for the vaccines are already sexually active and carrying HPV. Still, ob.gyns. should review the vaccine history with their patients and administer remaining or all doses as needed.

Both of the available vaccines – the quadrivalent HPV vaccine and the bivalent HPV vaccine – protect against viral genotypes 16 and 18, which are associated with 70% of cervical cancers. The quadrivalent vaccine provides extra protection against genotypes 6 and 11, which are associated with 90% of genital warts cases. Both vaccines protect against vulvar, vaginal, anal, and penile dysplasias.

The HPV vaccines have been used broadly throughout the world. In Australia, where vaccine coverage has been high, there is now evidence of herd immunity, with the number of males presenting with new diagnoses of genital warts declining even though females are the ones being vaccinated.

With respect to hepatitis B infection, sexual transmission is the most common mode of transmission in the United States, and in this sense, ob.gyns. have an important opportunity to ensure that women at risk for hepatitis B infection are vaccinated. Ob.gyns. should take a history of a sexually transmitted infection, in particular, as a trigger for action. It should be second nature for us to tell a patient who had gonorrhea 2 years ago that we recommend the hepatitis B vaccine for her.

A history of a sexually transmitted infection is only one of the risk factors for hepatitis B – others include recurrent or current injection drug use, previous incarceration, and exposure to blood products – but it is the one that most clearly calls us into a public health role. A significant number of women who see us during any given year do not see any other physicians or health care providers, so we cannot depend on other providers to take the lead on immunization.

Remember, you cannot always learn of a history of a sexually transmitted infection by simply asking, have you ever had a sexually transmitted infection? Women should be given a list of specific sexually transmitted infections and asked whether they’re ever had any of them. Research has shown that women commonly do not equate pelvic inflammatory disease or Trichomonas vaginalis, for instance, with sexual transmission.

Dr. Minkoff serves as chairman of the department of obstetrics and gynecology at Maimonides Medical Center, and is a distinguished professor of obstetrics and gynecology at SUNY Downstate Medical Center, both in Brooklyn, N.Y. Dr. Minkoff reported that he has no disclosures relevant to this Master Class.