What is PrEP?
PrEP stands for Pre-exposure Prophylaxis, which, if taken correctly, protects against HIV infection. In PrEP therapy, a non-HIV infected person takes one tablet a day that contains two anti-HIV medications (tenofovir + emtricitabine). It is a widely recognised way of preventing HIV infection in many countries and follows the recommendations of the Polish AIDS Scientific Society.
Before the start of PrEP, the following test results are required:
- negative HIV IV (anti-HIV/p24 antibodies) – up-to-date test result (taken up to 7 days before the start of PrEP)
- negative syphilis,
- general blood, creatinine, general urine
- no symptoms of other sexually transmitted diseases (e.g. gonorrhoea)
Additionally recommended (ideal scenario):
- test to exclude hepatitis A, B, C infection (HAV, HBV, HCV), Chlamydia
- information on previously taken vaccinations against HAV and HBV or vaccination against these viruses
The PrEP protects against HIV transmission only! Therefore, it is recommended to use a condom as it protects against other sexually transmitted diseases.
How PrEP is to be taken?
Continuous method: 1 tablet daily at the same time for a period of sexual activity
Ad hoc (on demand): during holidays, with planned weekend sex, before certain events/parties
Emergency PrEP consists of 4 tablets: 2 tablets taken 2-12 hours before intercourse, one tablet 24 hours after intercourse, and one tablet 48 hours after intercourse.
What is PrEP efficacy?
The efficacy and safety of PrEP have been assessed in several large clinical trials among men who have sexual contact with other men (MSM), men who have sexual contact with women, and women who have sexual contact with men. At first, they were tested for HIV infection to see if they were already infected. It was then recommended they took one tablet of tenofovir with emtricitabine once a day. In addition, trial participants received extensive advice on the principles of safer sex as well as a supply of condoms, and were regularly tested for other sexually transmitted infections.
Studies have shown that PrEP reduces the risk of HIV infection. For MSM, the risk was reduced by 44% compared with the placebo group (i.e. without the drug). The value of 44% is the average for all participants in the trial. It applies to both those who took the drug regularly and those who took it irregularly or did not take it at all. In the group of people who declared to have taken most of the doses of PrEP, the risk decreased by 72%, and sometimes even by 96%.
In heterosexual couples where one person was HIV-infected, the use of PrEP reduced the risk of infection by 75% compared to the placebo group. In the group of those participants who declared to have taken most doses of the medication, the risk was reduced by 90%. In another trial for men and women (not in relationships) taking PrEP, the risk of HIV infection was reduced by 62% and by 85% for those who have taken most doses. In one trial, only less than 26% of women had protective blood levels, which was explained by the fact that most women in the trial did not take the tablets. Therefore, these women were not protected against HIV infection at all.
Numerous clinical trials have demonstrated the efficacy of tenofovir and emtricitabine combined in one tablet. These drugs block important steps in the virus replication cycle and make the infection less possible. Taken as prescribed, due to the presence in the blood and other tissues, they quite effectively prevent the virus from entering the body and halt the development of a chronic infection. If taken irregularly, the amount of active substances in the body may be too low to prevent the infection. That is why it is so important to take the tablets regularly once a day and at regular times. It is also possible to take these medications on an ad hoc basis (4 tablets in total: 2 tablets 2-24h before intercourse, one tablet 24h after intercourse and one tablet again, 48h after intercourse), which gives a similar degree of protection against HIV infection during anal contact as taking them daily. These “ad hoc” dosages have only been tested among MSM group.
Is PrEP for you? YES, if at least one of the following statements applies to you:
- you don’t use condoms when you have intercourses with partners who you can’t say aren’t HIV-positive
- you use drugs and/or drink alcohol during sexual intercourse
- you use condoms, and you want to be 100% sure that you will not be infected with HIV during an accidental sexual contact
- you do not want to experience anxiety or infection if a condom breaks during an intercourse
- you are afraid that you will contract HIV from your regular partner who is infected and is not following a treatment plan