1 dose of HPV vaccine may be enough to prevent cervical cancer

“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.”

Data for this study are from the NCI-funded phase III clinical trial to test the efficacy of Cervarix in women from Costa Rica. About 20 percent of the women in the study received fewer than three doses of the vaccine, not by design.

The researchers looked for the presence of an immune response to the vaccine (measured by antibody levels) in blood samples drawn from 78, 192, and 120 women who received one, two, and three doses of the vaccine, respectively, and compared the results with data from 113 women who did not receive vaccination but had antibodies against the viruses in their blood because they were infected with HPV in the past.

They found that 100 percent of the women in all three groups had antibodies against HPV 16 and 18 in their blood for up to four years. Antibody levels were comparable for women receiving two doses six months apart and those receiving the full three doses.

The researchers also found that while antibody levels among women who received one dose were lower than among those who received the full three doses, the levels appeared stable, suggesting that these are lasting responses. In addition, the levels of antibodies in women from the one- and two-dose groups were five to 24 times higher than the levels of antibodies in women who did not receive vaccination, but had prior HPV infection.

“Our findings suggest promise for simplified vaccine administration schedules that might be cheaper, simpler, and more likely to be implemented around the world,” said Safaeian. “Vaccination with two doses, or even one dose, could simplify the logistics and reduce the cost of vaccination, which could be especially important in the developing world, where more than 85 percent of cervical cancers occur, and where cervical cancer is one of the most common causes of cancer-related deaths.”

In some parts of the world, including Chile and British Columbia, two doses of HPV vaccine is now the recommended vaccination program, according to Safaeian. But for a single HPV dose, “while our findings are quite intriguing and show promise, additional data are needed before policy guidelines can be changed,” she clarified. “For instance, it is important to note that persistence of antibody responses after a single dose has not been evaluated for Gardasil, the quadrivalent HPV vaccine that is more widely used in the United States and many other countries.”

This clinical trial was sponsored by the NCI with support from the National Institutes of Health Office of Research on Women's Health and the Ministry of Health of Costa Rica. The HPV vaccine was provided by GlaxoSmithKline Biologicals. Safaeian declared she has no conflicts of interest.

To interview Mahboobeh Safaeian, contact the NCI Press Office at ncipressofficers@mail.nih.gov or 301-496-6641. For other inquiries, contact Jeremy Moore at jeremy.moore@aacr.org or 215-446-7109.

Follow the AACR on Twitter: @AACR
Follow the AACR on Facebook: http://www.facebook.com/aacr.org
About the American Association for Cancer Research
Founded in 1907, the American Association for Cancer Research (AACR) is the world's oldest and largest professional organization dedicated to advancing cancer research and its mission to prevent and cure cancer. AACR membership includes more than 34,000 laboratory, translational, and clinical researchers; population scientists; other health care professionals; and cancer advocates residing in more than 90 countries. The AACR marshals the full spectrum of expertise of the cancer community to accelerate progress in the prevention, biology, diagnosis, and treatment of cancer by annually convening more than 20 conferences and educational workshops, the largest of which is the AACR Annual Meeting with more than 18,000 attendees. In addition, the AACR publishes eight peer-reviewed scientific journals and a magazine for cancer survivors, patients, and their caregivers. The AACR funds meritorious research directly as well as in cooperation with numerous cancer organizations. As the scientific partner of Stand Up To Cancer, the AACR provides expert peer review, grants administration, and scientific oversight of team science and individual grants in cancer research that have the potential for near-term patient benefit. The AACR actively communicates with legislators and policymakers about the value of cancer research and related biomedical science in saving lives from cancer. For more information about the AACR, visit http://www.AACR.org.

Media Contact

Jeremy Moore EurekAlert!

Weitere Informationen:

http://www.aacr.org

Alle Nachrichten aus der Kategorie: Health and Medicine

This subject area encompasses research and studies in the field of human medicine.

Among the wide-ranging list of topics covered here are anesthesiology, anatomy, surgery, human genetics, hygiene and environmental medicine, internal medicine, neurology, pharmacology, physiology, urology and dental medicine.

Zurück zur Startseite

Kommentare (0)

Schreib Kommentar

Neueste Beiträge

Alien species to increase by 36% worldwide by 2050

The number of alien (non-native) species, particularly insects, arthropods and birds, is expected to increase globally by 36% by the middle of this century, compared to 2005, finds new research…

Geothermal energy: Fraunhofer IEG operates simulator for drilling at depths up to 5,000 meters

To tap into geothermal reservoirs, boreholes must be drilled deeply into the earth’s crust. Due to the extreme pressures and temperatures involved, this is expensive and time consuming. A research…

Immune cells as guests in the tissue

Specialized immune cells settle permanently in tissues of the body and build “local task forces”. Wuerzburger scientists have recently discovered, how these cells can regenerate themselves and can adapt to…

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close