Women vaccinated with one dose of a human papillomavirus (HPV) vaccine had antibodies against the viruses that remained stable in their blood for four years, suggesting that a single dose of vaccine may be sufficient to generate long-term immune responses and protection against new HPV infections, and ultimately cervical cancer, according to a study recently published .
"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 percent of girls between 13 and 17 years old initiated HPV vaccination, and only 33.4 percent of them received all three doses," said Mahboobeh Safaeian, Ph.D., an investigator in the Division of Cancer Epidemiology and Genetics at the National Cancer Institute (NCI) in Bethesda, Md.
"We wanted to evaluate whether two doses, or even one dose, of the HPV 16/18 L1 VLP vaccine [Cervarix] could induce a robust and sustainable response by the immune system," she added. "We found that both HPV 16 and HPV 18 antibody levels in women who received one dose remained stable four years after vaccination. Our findings challenge previous dogma that protein subunit vaccines require multiple doses to generate long-lived responses."