No evidence for potential competition between human papillomavirus types in men
| November 15, 2011 | |
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The Centers for Disease Control and Prevention Advisory Committee on Immunization Practices recently recommended that teenage boys be vaccinated against the human papillomavirus (HPV). HPV vaccines target the two most common types of the virus that cause cervical cancer: HPV 16 and 18. However, as more and more people are vaccinated, might this result in an increase of other types of HPV that cause cancer? One of the first-ever, UNC-led epidemiological studies to examine HPV-type competition in men found little evidence for potential type competition. Previous studies in women report similar findings. Their findings are published in the Nov. 4 online edition of the Journal of Infectious Diseases. Carcinogenic types of human papillomavirus infection are the main cause of cervical cancer in women and are responsible for other genital cancers, including anal and penile cancer in men. It is also increasingly linked to head and neck cancers. Viral type competition occurs when different types of a particular virus compete for dominance. The dominant HPV types in cervical cancer are the targets of the vaccines currently available. Study scientists did not find any other non-vaccine HPV types to be candidates for type-competition in men. 
Dr. Jennifer Smith
“In our study,” said senior author Jennifer S. Smith, PhD, MPH, “we wanted to know if any specific HPV type was less likely to be found with another HPV type, which could indicate possible competition of one type over another. Our data, among men prior to any vaccine introduction, do not suggest that one HPV type will dominate another.” Smith is research associate professor of epidemiology at UNC Gillings School of Global Public Health and member of UNC Lineberger Comprehensive Cancer Center.”We do not yet know if type competition occurs,” said Anne F. Rositch, PhD, MSPH, the study first author. “Although these data are reassuring, we will need pre- and post-vaccination surveillance data to determine if there is a change in the types of HPV causing cancer.”
Dr. Anne Rositch
Rositch, an alumna of the UNC public health school, is a postdoctoral fellow at Johns Hopkins Bloomberg School of Global Public Health. The study was conducted among 2,702 HIV-seronegative men in Kisumu, Kenya, who were tested for HPV types, and 57 percent of those tested positive for HPV infection. The scientists identified positivity to more than 40 HPV types and studied them for potential type competition, but found none. Other authors from the UNC public health school are Charles Poole, PhD, associate professor of epidemiology, and Michael Hudgens, PhD, research associate professor of biostatistics. Other authors are from the Universities of Nairobi, Manitoba and Illinois, and the Vrije Universiteit Medical Center in Amsterdam, the Netherlands. Research funding was provided by the National Cancer Institute, the National Institutes of Health; the Division of AIDS, National Institute of Allergy and Infectious Diseases and the Canadian Institutes of Health Research. UNC Gillings School of Global Public Health contact: Ramona DuBose, director of communications, (919) 966-7467 or ramona_dubose@unc.edu. |
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