New Study Supports Cervical Cancer Vaccine
Vaccines are responsible for some of the greatest successes in medical history.
Now, exciting data about a new cervical cancer vaccine in development supports
the potential for vaccines to continue to have a tremendous impact in the near
future. The medical journal Lancet Oncology published a study (4/05) showing
that Gardisil™, a vaccine to prevent human papilloma virus (HPV) could
reduce persistent HPV infection and related disease (including new cervical
pre-cancers and genital warts) by 90%. The vaccine is expected to become available
in the United States in 2006.
Why is this necessary? Up to 70% of sexually active women will become infected
with HPV during their lifetime. Worldwide, cervical cancer is the second most
common cause of cancer-related death in women. Worldwide, HPV causes nearly
470,000 cases of cervical cancer each year. For nearly 31,000 women per year
in Europe and nearly 4,000 women per year in the United States, cervical cancer
is fatal. HPV infections are also responsible for genital warts in 1-2%
of young adults. Genital warts can cause pain as well as sexual dysfunction.
Recurrence is common and treatment is inconvenient, uncomfortable, and expensive.
There are more than 100 strains of HPV that have been identified. Ten of them
have been shown to significantly increase the risk of cervical cancer. This
study, conducted by Luisa Villa (Ludwig Institute for Cancer Research, Brazil)
and colleagues, tested the effectiveness of a vaccine which targets four strains
of HPV: types 16 and 18, which are associated with 70% of cervical cancers and
types 6 and 9, which are associated with 90% of genital warts. The study evaluated
552 healthy women aged 16-23 from Brazil, Europe and the USA. These women were
not pregnant, had no previous abnormal cervical smears and reported a history
of four or fewer sexual partners. 277 women were randomly assigned to receive
3 doses of the intramuscular vaccine over a 6 month period; 275 women received
a placebo. The women were followed up for 36 months and underwent regular gynecological
examinations, tests for HPV DNA, and cervical smears. After 3 years, the incidence
of persistent infection or disease with HPV 6, 11, 16, or 18 fell by 90% in
those who received the vaccine compared with those given placebo. The vaccine
was 100% effective against precancerous cervical lesions and genital warts associated
with these four HPV types. There were no vaccine related serious adverse events
The study authors suggest that universal HPV vaccination might be most effective
if implemented in 10-13 year olds, who are likely to be HPV negative.
According to another study, a female college student had a 60% likelihood of
becoming infected with HPV during her four years in college. Vaccinating 10
to 13 year olds is likely to meet with some resistance, however, by parents
reluctant to admit that their children might become prematurely sexually active
or might ever become at risk for a sexually transmitted infection.
Created: 4/29/2005  - Donnica Moore, M.D.