Cervical Cancer Vaccine on the Way
100% Protective Against Disease continued...
Both Merck and GlaxoSmithKline have begun much larger trials of their respective vaccines. Villa tells WebMD that early results from Merck's investigation are expected later this year. If the trials go well, the company hopes to introduce the vaccine late in 2006, she says.
Most experts agree that the vaccine will have the most impact if given to young girls in countries that don't screen for cervical cancer and before they become sexually active.
But its impact in the U.S. and other developed nations, where cervical cancer rates are low due to screening, is unclear, says Debbie Saslow, PhD, director of breast and gynecological cancers for the American Cancer Society.
The vaccine will not replace Pap smears, she says, because the vaccine does not protect against about a dozen HPV strains that cause between 25% and 30% of cervical cancers. And there is some concern that vaccinating against the two major cervical cancer agents will lead to an increase in these other cancer-causing strains.
"This vaccine could have a huge impact if you could vaccinate young girls in countries that don't have routine cervical cancer screening," Saslow tells WebMD. "But these are the countries that are going to be least able to afford it. And within the U.S. it isn't likely that people who are not being screened will get vaccinated."
Saslow says the vaccine has a lot of potential, but there are a lot of unanswered questions about its use.
"Even if this vaccine isn't perfect, it is still very exciting to think that within a few years we may have one that really can prevent all cervical cancers," she says.
