Infection With Vaccine-Protected HPV Strains Down
AUGUST 17, 2012
The results of a recent study show that cases of human papillomavirus are down due to vaccination, and research in the area of severe food allergies uncovers an alarming trend of caregivers failing to administer epinephrine.
Cases of human papillomavirus (HPV) from vaccine-protected strains decreased after licensing of an HPV vaccine, according to the results of a study published online July 9, 2012, in Pediatrics.
Merck & Co, Inc, released Gardasil, the first HPV vaccine, in 2008. The vaccine protects against diseases caused by HPV types 6, 11, 16, and 18, including cervical cancer, genital warts, and precancerous or dysplastic lesions. It is indicated for use in girls and women aged 9 to 26 years, and for the prevention of genital warts caused by HPV in boys and men aged 9 to 26 years.
At the time of the study, Gardasil was the only HPV vaccine available. The FDA has since approved a second HPV vaccine, Cervarix (GlaxoSmithKline), which protects against HPV types 16 and 18, and is indicated for female use only.
Researchers recruited women aged 13 to 26 years from 2 primary care clinics for a prevaccination surveillance study from 2006 to 2007. None of the 368 participants were vaccinated at the time of the questionnaire. They then recruited 409 additional participants from 2009 to 2010 for a post-vaccination surveillance study; 59% of the participants were vaccinated, they said. Participants completed a questionnaire and were tested for HPV during both surveillance periods.
Of the participants surveyed and tested from 2006 to 2007, 31.7% of participants had 1 of the 4 vaccinecovered HPV strains. In 2009 to 2010, however, only 13.4% of participants had 1 of the 4 vaccinecovered HPV strains. Among those who were vaccinated, infection rate decreased from 31.8% to 9.9% between the 2 study periods.
The reduction in infection of HPV strains covered by the vaccine also extended to those who did not receive the vaccine, study authors noted. In unvaccinated participants, 30.2% were determined to have a vaccine-covered HPV strain from 2006 to 2007, whereas 15.4% of unvaccinated participants had a vaccine-covered HPV strain from 2009 to 2010.
Despite the decrease in prevalence of vaccine-covered HPV strains, infection with non–vaccinecovered HPV strains increased during the study period, researchers said. During 2006 to 2007, study authors reported 60.7% of participants were infected with a non– vaccine-covered HPV strain. From 2009 to 2010, 75.9% of participants were determined to be infected with a non–vaccine-covered HPV strain.