Table 1 HIV biomedical prevention trial vignettes

1. Oral PrEP

 You are pregnant. You get asked whether you would be willing to join a study to evaluate whether daily use of an anti-HIV pill can be safely used during pregnancy to prevent HIV. You will be asked to take the medication daily and to continue to take it for 6 months after you give birth. The medication has been tested in two different kinds of women who are a lot like you. It works in women who are not pregnant to reduce the chances of HIV infection. And it works for women who are pregnant but already have HIV, as a way to prevent them from passing HIV to their babies. But it has not been tested extensively in pregnant women like you who do not have HIV but want to protect themselves from infection.

2. Vaginal ring

 You are pregnant. You get asked whether you would be willing to join a study to evaluate whether monthly use of a vaginal ring, which releases an anti-HIV medication, can safely prevent pregnant women from getting HIV. The ring is a flexible plastic device that you put in the vagina. You change it once a month. You will use it during pregnancy and for 6 months after giving birth. It seems to work in women who are not pregnant to prevent HIV. Also, the medicine in the ring has been used in pills for pregnant women who have HIV and is thought to be safe. But the ring itself has not been tested in pregnant women.

3. Randomized control trial (RCT): oral PrEP vs. vaginal ring

 You are pregnant. You get asked whether you would be willing to join a study about the safety and effectiveness of the two prevention methods discussed above (the vaginal ring and the daily pill). No one knows if the ring or the daily pill will work better than the other. If you join the study, whether you get the ring or the pill will be decided by a process called randomization. When patients are randomized to one drug or the other, it makes it easier for the researchers to understand the study’s results. Randomization works something like a gumball machine with red and blue gumballs in it. If you get a red gumball, you get one medicine, and if you get a blue gumball, you get the other medicine. You don’t know whether you will get the red gumball or the blue gumball, but you know you will get a gumball and therefore some kind of medicine.