Should pre-exposure prophylaxis be rationed or targeted? Experts urge ethics debate

Debates about the roll-out of pre-exposure prophylaxis - antiretroviral treatment that can prevent HIV infection - will need to tackle some serious ethical questions about who gets access to the drugs, say researchers from the US Centers for Disease Control and the University of Oxford in a special HIV-focused issue of The Lancet this month.

Since the advent of tenofovir and emtricitabine, treatment is available that meets the criteria for long-term use in healthy people - eg, high potency, simple dosing, low adverse effects, and low frequency of drug-induced resistance, they argue.

The availability of PrEP raises important ethical questions, note the authors, such as: “what are the obligations of governments and industry to provide such prophylaxis? How should resources be distributed between research, treatment, counselling, testing, primary prevention, PrEP, and post-exposure prophylaxis (PEP)? Who should have priority for prophylaxis?”

In a viewpoint article in The Lancet Lynne Paxton of the US Centers for Disease Control and Tony Hope and Harold Jaffe of the University of Oxford acknowledge that HIV-related stigma poses particular challenges, since this can affect decision-making.

For example, one argument against provision of PrEP for groups such as sex workers, drug users, and men who have sex with men “is based on the idea that providing prophylaxis expresses approval for high-risk behaviours”, analogous to arguments used against needle exchanges or condom provision to teenagers .

Thus far, several studies of potential interventions to reduce HIV transmission have not led to an increase in unsafe sexual behaviours, although that issue needs to be evaluated in the studies of PrEP, the authors advocate.

But they go further in rejecting this argument. “First, public-health policy should aim for prevention of ill-health rather than judgments of individual’s morality. Second, we do not believe that provision of prophylaxis condones risky behaviour; but rather, it acknowledges the reality of the epidemic.”

“Another issue is the perception that people choosing risky behaviours should be at lower priority for prevention than those whose risk is not affected by their behaviour”, say the authors, citing as an example those infected via vertical transmission.

But, the authors ask, “even if personal responsibility for infection was considered in setting public-health priorities, how does one ascribe the degree of responsibility?”

They point to two examples: ill-health in a smoker who was brought up in an environment in which smoking was encouraged or the social and economic pressures on female sex workers in resource-poor countries.

“Generally, no method of ascribing personal responsibility for disease is reliable or valid. We therefore believe that neither judgments about morality, nor responsibility for risky behaviours should play a part in decision making about [PrEP]. Instead, public-health decisions should be based on relevant factors such as cost-effectiveness and clinical need.”

With three efficacy studies of PrEP now underway or about to start, one concern is that such programmes, if found effective, may be too expensive for the areas that have the greatest need, and many prevention programmes, of which PrEP would be part, already are underfunded.

“Nevertheless, the severity of the HIV epidemic and the potential benefits of pre-exposure prophylaxis should lead us to begin planning for implementation as soon as possible”, the authors urge. Which settings are appropriate? What level of efficacy would warrant widespread use? Which populations would benefit most?”

The authors propose that “in regions with HIV epidemics in specific groups, targeting of such groups (eg, sex workers, partners of people known to have HIV, and those attending sexual-health clinics) is probably the best strategy.

However, in areas with generalised epidemics, as is seen in some African countries, potential populations could include most sexually active adults.” They conclude: “Public-health decision makers need to start contingency planning now—trial results will be known soon”.