Figures from Public Health England have shown a dramatic decrease of 71 per cent in the HIV transmissions among gay and bisexual men since 2012.
The decline has been credited to the introduction of the pre-exposure prophylaxis pill (PrEP).
The drug is primarily targeted at men who have unprotected sex with other men, as well as people whose partners have HIV.
It is not used by those who already have HIV, who receive different treatments.
Clinical trials have shown PrEP to be most effective when taken in two particular ways, one regularly every day, or in larger doses before and after having sex.
It is believed that both methods, when correctly followed, are almost 100% effective at preventing transmission.