Mathematical models assess impact of prophylactic vaccine.

2003 JAN 1 - (NewsRx.com & NewsRx.net) -- The ongoing development of a vaccine against human papillomavirus (HPV) raises important questions about the impact of various vaccination strategies," University of Washington biostatisticians say.

They developed "two mathematical models ... to explore the population-level impact of an HPV vaccine. The first model focuses on the infection process and the second on the disease process (specifically, cervical carcinoma in situ and cancer)."

J.P. Hughes and colleagues ran the models and found "both population characteristics (i.e., sexual mixing and rates of sex partner change) and vaccine characteristics affect the steady state prevalence of HPV that would be expected if a vaccine program is implemented.

"Under a particular set of assumptions," they said, "we find that vaccinating both men and women against a specific HPV type would result in a 44% decrease in prevalence of that type whereas vaccinating only women would result in a 30% reduction. We also find that if a vaccine gives protection against some, but not all, high risk types of HPV, the reduction in disease may be less than the reduction in HPV because the remaining high risk HPV types may replace the disease caused by the eliminated types."

The ...