During 2007, more than 11,000 women in the United States were diagnosed with cervical cancer. Another 3,600 women died from it. The recently introduced Gardasil vaccine is expected to reduce the incidence of cervical cancer but it is most effective when girls get vaccinated before becoming sexually active.

A recent study from the Harvard School of Public Health suggests three ways to optimize the vaccination process to achieve maximum coverage using the most cost-effective means - universal vaccination during early adolescence, catching up with vaccinations in women between 13 and 20 years of age, and a revision of the screening recommendations for vaccinated women.

Gardasil protects a young woman from infection from the human papillomavirus (HPV), a sexually transmitted virus that causes genital warts, which can become cancerous over time. The vaccine given in the US protects against four strains of HPV - strains 6, 11, 16, and 18. Types 6 and 11 are associated with the development of JORRP, juvenile-onset recurrent respiratory papillomatosis, a respiratory condition often diagnosed in infancy that is rare but severe and often related to a mother’s genital wart infection. The latter two strains are thought to cause about 70% of all cervical cancers across the globe.

While the cancer-fighting value of the vaccine is understood, the most cost-effective way to administer the vaccine has not been established. Current policy recommends routine vaccination for all females aged 11 and 12, with all women aged 13 to 26 getting the vaccination as well. Most women are sexually active before turning 20, a situation that places more significance on vaccination at a younger age. The Harvard study examined the merits of catch-up vaccination programs that target women aged 18, 21, and 26.

The study suggests the most cost-effective means of administering the vaccine is to girls between the ages of 13 and 18, with the assumption the vaccine will provide protection for at least 20 years and a booster dose is given, if a booster is deemed necessary at a later date.

Current HPV screening recommendations are that sexually active women of all ages get an annual screening, either by Pap smear or by testing for HPV DNA. The Harvard research team suggests vaccinated women can effectively wait three to five years between screenings with no negative repercussions. Routine screening is still recommended, even after vaccination, in order to spot any infection from strains of HPV not included in the vaccine. By eliminating several screenings over a five-year period, the cost effectiveness of the vaccine increases.

The American Cancer Society, the Centers for Disease Control and Prevention, and the National Cancer Institute funded the Harvard study, full details of which are available in The New England Journal of Medicine.

Source: Harvard School of Public Health