June 21, 2011

HPV Vaccination Study

(Ivanhoe Newswire) -- An Australian study is the first to show reduction of high-grade cervical abnormalities (HGAs- the precursors to cervical cancer) in women, following the introduction of human papillomavirus (HPV) vaccination programs.

Australia introduced an HPV vaccination program, with the quadrivalent HPV vaccine, for all women aged 12-26 years between 2007 and 2009. In this study, the authors analyzed trends in cervical abnormalities (both high-grade and low-grade [LGAs]) in women in Victoria, Australia, before and after introduction of the vaccination program.

They found that after the introduction of vaccination, the incidence of HGAs in girls aged 17 years and younger fell by 38 percent as compared with before the vaccination program (from 80 percent to 42 percent among screened women, an almost 50 percent decline). No decline was seen for LGAs or in older age groups.

"Our finding that the decrease in HGA incidence occurred in the youngest vaccination cohort before it occurred in the older, catch-up cohorts (who were more likely to have been previously sexually experienced) reinforces the appropriateness of the targeting of prophylactic HPV vaccines to preadolescent girls," the authors were quoted as saying.

"Linkage between vaccination and screening registers is needed to confirm that this ecological observation is because of vaccination and to monitor participation in screening," the authors said.
"This is the first report of a decrease in incidence of high-grade cervical abnormalities within 3 years after the implementation of a population-wide HPV vaccination programme," the authors said.

SOURCE: The Lancet, published online June 16, 2011