The Need for Condoms on the HIV Prevention Pill

HIV pre-exposure prophylaxis (PrEP) is a powerful prevention tool. A daily dose of Truvada can reduce a person’s risk of getting HIV by as much as 92 percent. This seems especially true for men who have sex with men (MSM). Recent studies suggest that PrEP may be just as effective in gay or bisexual men who take as few as four pills per week.

As public acceptance of PrEP continues to grow, so, too, have concerns that the strategy could lead to the widespread abandonment of condoms as the primary (or at least traditional) form of HIV prevention. Is that really a problem? Or is PrEP effectiveness enough to allow for condomless sex under certain specific conditions?

Understanding PrEP, Condoms, and Sexual Behavior

Most studies investigating PrEP and condom use have been conducted in MSM populations, the group of which continues to carry the highest burden of HIV in the U.S. The majority of these have found that that condomless sex—or more specifically the intimacy of condomless sex—is the key motivation as to why couples and individuals choose PrEP as their primary form of protection.

Adding further impetus are statistics which show that at least one-third of MSM infections occur within a committed relationship. Even in couples where both partners are HIV-negative, high rates of condomless anal sex, both within and outside the relationship (90 percent and 34 percent, respectively), account for the equally higher rates of infection.

But even beyond the issues of intimacy and self-protection, other factors contribute significantly to a person’s decision to replace condoms with PrEP (as opposed to using them in tandem). These can include the reduction of HIV-related anxiety, the perceived control over one’s sexual health, or the simple desire to have children. Each can inform a person’s perception as to what is or is not "acceptable risk."

But does PrEP necessarily encourage condomless sex, particularly in mixed-status couples where one partner is HIV-positive, and the other is HIV-negative? Most research suggests that it doesn’t. In fact, whether within the construct of a relationship or without, sexual behaviors (including sexual risk-taking) were not seen to change significantly in persons who chose to use PrEP.

Instead, PrEP appeared to reinforce risk reduction behaviors in those who recognized themselves to be at high risk. This was particularly true for mixed-status couples, who are more likely to use multiple tools (including condoms and HIV treatment as prevention) to prevent transmitting HIV to the uninfected partner.

PrEP Was Not Created Equal

Age, however, appears to be the one factor by which PrEP and condomless sex do have a direct association. A 2016 study from the Adolescent Medicines Trial Network (ATN) for HIV/AIDS Interventions reported that 90 percent of MSM aged 18-22 engaged in condomless anal sex while on PrEP, and that the incidence only increased the more adherent a person was to therapy. (Adherence was qualified by higher concentrations of Truvada in an individual’s blood.)

The findings were significant insofar as they suggested that PrEP not only lowered a person’s perceived risk of infection but increased sexual risk-taking, at least in younger populations. More concerningly, the rate of drug adherence was seen to decline rapidly in this group—from a high of 56 percent at Week Four to only 36 percent by Week 48—during which time the high rate of sexually transmitted infections (22 percent) remained unchanged.

Whether risk behaviors would reverse in line with decreasing adherence rates remains unclear. What is clear is that high rates of syphilis, gonorrhea, and chlamydia only adds to the likelihood of HIV and can potentially negate the benefits of PrEP, particularly in young people who typically have more reduced adherence rates.

The Effect of PrEP on Women

Gender also plays an essential role in determining the efficacy of PrEP. In this regard, there remains a concerning gap in our understanding of PrEP in women. PrEP had long been considered a means for self-protection in women who were sexually disempowered.

However, in stark contrast to MSM trials, early research had shown that rates of failure were far higher among women on PrEP and that such failures were attributed mainly to inconsistent dosing. But was drug adherence actually that much worse in women than in men? Or were there other factors that contributed to the failures?

A 2014 study from the University of North Carolina (UNC) provided some insight, suggesting that PrEP may be less effective in women due to lower concentrations of the drug in vulnerable cervical and vaginal tissues.

The UNC researchers found that that absorption and distribution of Truvada within these cells fell well below those of anal and rectal tissues. Even with uninterrupted daily adherence, only 75 percent of women were able to achieve the same level of protection as MSM.

By contrast, it was suggested that PrEP could afford protection in MSM with as few as two to three pills per week. The disparity strongly supports the use of PrEP as complementary, rather than alternative, tool for HIV prevention in women.

PrEP Failures in Men Who Have Sex With Men

Even among MSM, the issue of PrEP and condomless sex remains a contentious and sometimes confusing one. And while PrEP has never been endorsed as a stand-alone strategy, most would acknowledge that its use is greatly motivated by already high rates of condomless sex among gay and bisexual men.

Moreover, increasing evidence of PrEP’s effectiveness in MSM, even among those with inconsistent dosing, has lowered the perceived risk even in high-risk individuals (i.e., those who engage in group sex, rough sex, or injecting drug use). But how closely do these perceptions align with actual risk?

The question was placed squarely in the spotlight in 2016 when reports emerged that two gay men had been infected with HIV despite taking Truvada daily. In both cases, media reports had suggested that the men had been infected with a rare type of HIV resistant to both tenofovir and emtricitabine (the two drug agents contained in Truvada).

Since then, two additional cases have emerged, the latest in March 2018 involving a 34-year-old gay man in North Carolina. While an extensive investigation confirmed that multi-drug resistance was to blame in three of the four cases, inconsistent PrEP usage was also confirmed.

Experts largely minimized the news, asserting that there was no cause for alarm and that the benefits of PrEP still vastly outweighed the consequences. And in this regard, they were correct. Less certain was the assertion that this type of HIV resistant could be considered "rare," or that the multi-drug resistance identified in both men was anything but usual.

As recently as 2016, epidemiological research from the Centers of Disease Control and Prevention concluded the resistance to tenofovir—the primary drug in Truvada—was already pegged at around 20 percent in North America and Europe and could be as high 50 percent in Africa.

While there is far less data on global emtricitabine resistance, several animal studies have shown that resistance to tenofovir alone is enough to cause a breakthrough in infections even with daily adherence to PrEP. 

Moreover, multi-drug resistance—or even multi-class drug resistance—is not an uncommon situation given the widespread dissemination of the virus. And when passed from one person to the next, the potential only increases, contributing to the rise in transmitted drug resistance seen in many newly infected individuals.

What This Tells Us

From the public health perspective, the message remains clear: PrEP is recommended as part of an informed HIV strategy, which includes the use of condoms and a reduction in risk behaviors.

Moreover, PrEP is not intended for all persons, but rather those considered to be at high risk. When used, PrEP should always be taken daily, without interruption, and with regular testing to confirm the status of the users and to avoid the development of side effects.

With that being said, informed decisions are rarely based on guidelines alone, and this is no less true when it comes to condoms. When considering whether to use condoms, always try to keep one thing in mind: prevention is not a one-way street.

To fully self-protect, you need to address not only your vulnerability to infection but the infectivity of your sexual partner. If your partner’s status is unknown (and you’re unable or unwilling to discuss this with him or her), you would be best served to take every precaution to avoid infection, including the use of condoms.

If, on the other hand, your partner is HIV-positive, it’s vital to assess whether he or she is on therapy. More importantly, you need to know whether an undetectable viral load has been achieved.

Many public health officials today are moving closer to declaring that persons with undetectable virus are at "negligible" risk of transmitting HIV (most recently Demetre Daskalakis, Assistant Commissioner of New York City’s Bureau of HIV/AIDS Prevention and Control). 

It is, therefore, reasonable to suggest that HIV therapy, when used in combination with PrEP, may provide ample protection against HIV in the absence of condoms—but only if viral activity is fully suppressed and if daily adherence to PrEP is assured.

What it doesn’t say is that there 0 percent chance of getting infected. Only complete sexual abstinence can guarantee that, and even that has its failings.