2 HPV vaccines are now available
With the licensure of an HPV2 vaccine for use in women in the United States (Cervarix, GlaxoSmithKline), 2 HPV vaccine products are now available for use.8 An HPV4 vaccine (Gardasil, Merck & Co.) was licensed in 2006. The TABLE compares the composition, dosing schedules, and precaution for these 2 products. Each requires 3 doses, but the age ranges and dosing schedules are slightly different. The HPV4 vaccine contains antigens against HPV types 16 and 18, which cause 70% of cervical cancers and precancerous lesions, and types 6 and 11, which cause 90% of anogenital warts.9
The HPV2 vaccine contains antigens for HPV types 16 and 18 only and does not protect against warts. The bivalent product appears to produce a higher level of antibody response and may provide better cross protection against other HPV types. ACIP compared effectiveness studies of both vaccines and decided to show no preference for either vaccine for the prevention of cervical cancer and precancerous lesions.
TABLE
HPV vaccines: A side-by-side comparison
| HPV4 | HPV2 | |
|---|---|---|
| Year licensed | 2006 | 2009 |
| Virus-like particle types | 6, 11, 16, 18 | 16,18 |
| Hypersensitivity-related contraindication | Yeast | Latex |
| Schedule | 0, 2, 6 months | 0, 1, 6 months |
| Age range | 9-26 years | 10-25 years |
The recommendation is for routine vaccination with an HPV product for all adolescent girls ages 11 to 12, with catch-up through age 26. If a female wants protection against anogenital warts, HPV4 is recommended. It is preferable to complete a 3-dose series with the same product, but if this is not possible, a series can be completed with the other product. The HPV4 vaccine is made using yeast, and prefilled HPV2 syringes contain latex. Hypersensitivity to these substances is a contraindication to their use. Patients who receive either vaccine should be observed for 15 minutes after the injection to prevent injury from syncope.
HPV4 in men. The HPV4 vaccine has now been licensed in the United States for use in males ages 9 to 26 to prevent anogenital warts. It may also protect against HPV-caused cancers (oral, genital, and anal), but the proof of that is still lacking. ACIP debated whether to recommend HPV4 for boys routinely at age 11 to 12 and decided against this. Instead the group voted for a “permissive” recommendation that states HPV4 may be given to adolescents and young men ages 9 to 26 to prevent warts and that protection is better if it is administered before exposure.10 This allows vaccine use in young males to be provided in the Vaccines for Children Program, but falls short of including it in the routine vaccine schedules.
The reasons for not recommending HPV4 routinely in young men were the cost and the perception that anogenital warts are primarily a cosmetic problem, although it was acknowledged that they can cause serious psychological morbidity. ACIP acknowledged that using HPV4 in men might lead to more protection for women because viral spread would be reduced, but stated that much more protection for women would be gained from a higher level of vaccination among women. As the evidence of protection against HPV-related cancers in men is gathered, ACIP will probably revisit this recommendation.
For a more detailed discussion of the issues posed by these 2 vaccines, see “The case for HPV immunization” in the Journal of Family Practice, December 2009.11
Rabies vaccine: 4 doses are sufficient
Due to a threatened shortage of rabies vaccine, ACIP commissioned a study to determine if a 4-dose series might be as effective as the licensed 5-dose series. The results showed that a reduced-dose series achieved equivalent antibody levels, so ACIP voted to recommend 4 doses of vaccine at days 0, 3, 7, and 14 postexposure.12 The vaccine should be part of a 3-pronged approach to prevent rabies after an exposure, along with rabies immune globulin administration and wound cleaning.13 The 4-dose schedule differs from the rabies vaccine package inserts and the FDA licensure information.
Tougher immunity criteria for health care personnel
Prior to 2009, criteria for proof of immunity to measles, mumps, or rubella among health care workers included serologic testing, history of 2 vaccines after age 1, physician-diagnosed disease, or being born prior to 1957. The new criteria require laboratory confirmation of a physician diagnosis and add a footnote to the “born before 1957” criterion that states: Institutions with unvaccinated health care workers who lack laboratory evidence of immunity should consider vaccinating them with 2 doses of MMR (for measles and mumps) and 1 dose of MMR (for rubella). In an outbreak, the new standards recommend inoculating unvaccinated health care personnel who do not have serological proof of immunity with 2 doses for outbreaks of measles or mumps and 1 dose during an outbreak of rubella.14,15