A simplified administration schedule of only 1 dose, instead of the current standard of 3 doses, of the human papillomavirus (HPV) vaccine appears to be all women need to be protected from cervical cancer, according to new data from a study funded by the National Cancer Institute (NCI) and recently published (Safaeian M, et al. Cancer Prev Res [Phila]. 2013;6:1242-1250).
“The latest Morbidity and Mortality Weekly Report from the Centers for Disease Control and Prevention on vaccination coverage indicates that in 2012, only 53.8% of girls between 13 and 17 years old initiated HPV vaccination, and only 33.4% of them received all 3 doses,” said Mahboobeh Safaeian, PhD, Division of Cancer Epidemiology and Genetics at NCI. “We wanted to evaluate whether 2 doses, or even 1 dose, of the HPV 16/18 L1 VLP vaccine [Cervarix] could induce a robust and sustainable response by the immune system.”
In their study, Dr Safaeian and her team found that 100% of the women who received 1, 2, or 3 doses of the HPV vaccine (Cervarix) had antibodies in their blood against HPV 16 and HPV 18 for up to 4 years, regardless of the dosing schedule.
“We found that both HPV 16 and HPV 18 antibody levels in women who received one dose remained stable 4 years after vaccination. Our findings challenge previous dogma that protein subunit vaccines require multiple doses to generate long-lived responses,” Dr Safaeian said.
In addition, the team found that although antibody levels were lower among women who received only 1 dose of the vaccine than in women who received the 3 doses, the antibody levels were stable in the former cohort, suggesting that these responses endure and can provide sufficient protection. These findings may change the practice of HPV vaccination, according to Dr Safaeian.
“Our findings suggest promise for simplified vaccine administration schedules that might be cheaper, simpler, and more likely to be implemented around the world,” said Dr Safaeian. “Vaccination with 2 doses, or even 1 dose, could simplify the logistics and reduce the cost of vaccination, which could be especially important in the developing world, where more than 85% of cervical cancers occur, and where cervical cancer is one of the most common causes of cancer-related deaths,” she predicted. American Association for Cancer Research; November 4, 2013
