vaccine-like drug administered once a year to prevent HIV could be ready just after 2030, according to drugmaker ViiV, transforming management of a virus that has killed nearly 40mn people in an epidemic that has lasted more than four decades. While there is no vaccine to treat HIV, a virus that can lead to Aids, pre-exposure prophylaxis (PrEP) has reduced transmission rates by offering protection to those who may be exposed to the virus. While there is no vaccine to treat HIV, a virus that can lead to Aids, pre-exposure prophylaxis (PrEP) has reduced transmission rates by offering protection to those who may be exposed to the virus.