HIV vaccine trial in South Africa

i dont know about you but this trial bothers me. why do Africans have to be the guinea pigs? im not sure why Merck could not test the vaccine in America or China. it bothers me for two reasons. first, i feel like it will promote risky behavior. second, remember the recently canceled study for the hiv microbicidal gel in which 30 of the 1300 participants were infected with the virus.

i understand the importance of human testing. but i am concerned that some of the participants are not fully aware of the risks involved. i personally would be unwilling to participate in such a study, the risks are too high.