Could HIV Prevention Pills Actually Increase Infection Risk by Cutting Condom Use?
It's been hailed as a major breakthrough and one of the much-needed tools to "end HIV". But there are also concerns about pre-exposure prophylaxis (PrEP), the use of antiretroviral drugs by HIV-negative people to prevent them from becoming infected with the virus. Will people taking PrEP stop using condoms and could this actually lead to an increase in HIV and sexually transmitted infections (STIs)?
PrEP appears to be a highly effective method of reducing risk of HIV transmission. Adding to growing international evidence, the Proud trial tested the use of PrEP with gay and bisexual men in England and found a reduction in HIV transmission of 86% amongst men who took PrEP every day. Truvada, the drug used in the Proud trial, is not currently licensed for use as PrEP in the UK. However, as a result of the findings, there has been a concerted effort by HIV policymakers and community activists to make Truvada available as PrEP on the NHS as soon as possible.
Evidence to date has shown mixed results when it comes to continued condom use with PrEP. The Proud trial, which recruited participants reporting some but not exclusive use of condoms, found the number of people not using condoms remained the same throughout the study. STI rates across both trial arms -- the group that received PrEP immediately and the group that had to wait 12 months -- also remained similar. Evidence from three locations from the iPrEX study in the US suggests that, although some younger participants reduced condom use, in most cases PrEP did not reduce condom use but did reduce stress, fear, and guilt.
We need to consider who might be willing to use PrEP. A number of surveys with gay and bisexual men in the UK have shown that men reporting lower levels of condom use and who are at higher risk of HIV are interested in PrEP. Introducing PrEP to this group might not necessarily reduce condom use, but could protect against HIV infections where condoms are not already being used. In this way, PrEP could fill a gap in HIV prevention for those individuals who find it difficult, or are unable, to use condoms as their main means of preventing HIV.
Our PrEP research in Scotland with gay and bisexual men, and men and women from migrant African communities, found that concerns about PrEP went beyond condom use. Participants in our qualitative study highlighted anxieties around the immediate and long-term side-effects of PrEP, a lack of trust that PrEP would work, and a belief that they were not at high-enough risk to merit taking a daily pill to prevent HIV. In addition, given that PrEP is not 100% effective, skills amongst participants in calculating risk reduction in relation to PrEP appeared to be mixed and will be an important factor in the effective "real-world" use of PrEP.
But our study also highlighted the fear that others would stop using condoms as a result of PrEP. One man compared the impact of PrEP to "women burning their bras" because he was concerned that other men would stop using condoms and threaten a 30-year history of HIV-prevention based on condom use. This suggests that many people still see condoms as the main HIV-prevention tool and demonstrates the need to engage with these fears and identify how PrEP might fit into, rather than disrupt, existing HIV prevention strategies.
Given the likely introduction of PrEP in the UK in the not-too-distant future, we need to draw on existing evidence to encourage its equitable introduction into health services and access by those most at risk of HIV. There needs to be clear guidance and support for using PrEP in combination with existing HIV-prevention strategies, including condoms. We need to find acceptable, effective and clear ways of explaining PrEP to potential users and work to improve understandings and skills in assessing and reducing risk.
Finally, we need to address existing -- and sometimes conflicting -- community concerns about PrEP . We need to find ways of talking openly about what a range of HIV prevention options might look like, without moralising or judging individual practices. Good sexual health needs to recognise the dynamic lives of people affected by HIV. No matter how well PrEP might work, it alone will not be the magic bullet to end HIV.
Lisa McDaid is Programme leader, MRC/CSO Social and Public Health Sciences Unit at University of Glasgow.
Ingrid Young is Research fellow, MRC/CSO Social and Public Health Sciences Unit at University of Glasgow.