PROMISING RESULTS FROM HIV PREVENTION DRUG TRIAL, BUT MORE RESEARCH NEEDED.
Condoms still the best defence against HIV transmission.
HIV drugs still not available globally to people already living with HIV/AIDS.
NOVEMBER 23, 2010 - A study published in the New England Journal of Medicine has demonstrated that the use of two antiretroviral medications
(used to treat HIV-positive people) lowered the risk of infection in HIV-negative study participants by an average of 43.8%. The AIDS Committee of Toronto (ACT) welcomes the trial results, as they demonstrate that new HIV prevention technologies can be part of a comprehensive strategy to
prevent transmission of HIV, the AIDS-causing virus that infects two people in Toronto every day.
However, more research is needed on this technology - called Pre-Exposure Prophylaxis (PrEP) - before its use can be implemented and advocated, for several reasons:
- While the results are statistically significant and demonstrated a 43.8% risk reduction in study participants, the researchers calculated that 95% of
the time, the risk of infection can be lowered anywhere from 15.4 to 62.6%.
- Only about half of the study participants took the medication consistently, significantly reducing the drug's efficacy. This raises questions about
how practical this prevention method would be.
- HIV-positive people who take PrEP may develop and transmit drug-resistant strains of HIV. Given that 30% of Canadians living with HIV are unaware
of their status, frequent testing would be required to monitor if those taking PrEP are already HIV-positive or become infected while taking the drug.
- As with most medications, there are side effects. They not only have an impact on physical and mental health, but may also reduce adherence to the
drug, which has been shown to minimize its efficacy.
- Antiretroviral medications are expensive. With financial and geographic barriers preventing access to treatment for people who are already HIV-positive,
how would the drug be accessible to HIV-negative people at risk of HIV infection?
- Participants of this study were gay, bisexual, other men who have sex with men, and trans women in Brazil, Ecuador, Peru, South Africa, Thailand and
the United States. The results of this study cannot be extrapolated to predict the efficacy of PrEP on other populations.
- Although trial participants reported lower HIV risk behaviour (due to counselling and other prevention services provided as part of the study), more
research is needed to see if the trial results will have an impact on condom use - which is still the most effective protection against HIV transmission.
Despite demonstrating lower efficacy than existing HIV prevention methods (such as correct and consistent condom use), new prevention technologies such
as PrEP may still be useful for those at risk of HIV infection, where existing methods aren't working.
However, universal access to antiretroviral treatment must be prioritized for people who are already HIV-positive. UNAIDS estimates that only 36% of people
living with HIV/AIDS globally who need antiretroviral treatment were able to access it a year ago. Today, Canada remains one of the few industrialized countries
without a nationally-supported catastrophic drug program, resulting in unequal access to treatment for HIV-positive Canadians.
ACT supports a comprehensive approach to the HIV/AIDS crisis. Pre-Exposure Prophylaxis can be part of the prevention response to HIV/AIDS, and must be
researched and developed in combination with:
- Access to condoms (male and female/receptive) and other barriers;
- Universal access to antiretroviral drug therapy and other treatments for people living with HIV/AIDS;
- The development of microbicides (for both vaginal and anal use);
- Post-exposure prophylaxis;
- Voluntary, confidential and anonymous testing for HIV and other sexually transmitted infections; and,
- Needle exchanges and other harm reduction initiatives.
ACT congratulates and thanks the researchers and participants in the Pre-Exposure Prophylaxis Initiative (iPrEx) for these promising results.
For more information, please contact:
AIDS Committee of Toronto (ACT)
416-340-8484 ext. 225
"Reproduced with permission - AIDS Committee of Toronto (ACT)"
AIDS Committee of Toronto (ACT)