Summary:

This paper presents a model for assessing the potential effect of an HIV/AIDS preventative vaccine in South Africa, and for calculating the amount of the vaccine that would be required. A number of different hypothetical vaccine profiles and vaccine distribution strategies are considered. The study takes into account the change in behavior after vaccination due to a reduced fear of HIV infection or its consequences; the acceptance rate of the vaccine; and the proportion of population completing the vaccination series. The model used for the study is the ASSA2002 vaccine model, which is based on the ASSA2002 AIDS and demographic model.

Results suggest that a sterilising vaccine, which blocks infection, could reduce the HIV incidence between 2015 and 2025 by up to 50%, while a disease-modifying vaccine (which reduces viral load and delays the progression to AIDS in individuals who become infected with HIV after vaccination) would be unlikely to reduce HIV incidence by more than a third.  The effect on AIDS mortality over the same period would be substantially smaller, and it is unlikely that any preventive vaccine would reduce AIDS mortality by more than 10% between 2015 and 2025.

 http://www.actuarialsociety.org.za/Portals/1/Documents/4e0064f8-68c3-4309-bdca-4fe5c442d40b.pdf