So, this is a creative (and apparently successful) approach to reducing HIV infection rates. I wonder why this works, when abstinence pledges and the like don't?
"The spread of HIV in the 1980s caused blood transfusion services across the world to seek new strategies to collect safe blood. In 1989, Zimbabwe started targeting a new pool of low-risk donors: students aged 16-19. The first of these students became so committed to the venture that when they completed their schooling they decided to create the Pledge 25 Club, committing to make at least another 25 blood donations before the age of 25.
"The initiative was particularly successful in keeping these young people protected from HIV and other illnesses since part of their pledge was that they would maintain a healthy lifestyle in order to give safe blood. Indeed, statistics show that HIV infection rates among blood donors fell from 4.45% in 1989 to 0.61% in 2001, in a country where the infection rate in the sexually active population was 33.7% at the time.'