Eyal et al have recently argued that researchers should consider conducting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) human challenge studies to hasten vaccine development. We have conducted (J. L.) and overseen (L. D.) human challenge studies and agree that they can be useful in developing anti-infective agents. We also agree that adults can autonomously choose to undergo risks with no prospect of direct benefit to themselves. However, we disagree that SARS-CoV-2 challenge studies are ethically appropriate at this time, for (...) 3 reasons: (1) current scientific knowledge of SARS-CoV-2 infection is insufficient to manage risks; (2) autonomous decision making, while necessary, does not override concerns about risk; and (3) undertaking challenge studies now would imperil confidence in the research enterprise, potentially undermining the global response to the coronavirus disease 2019 (COVID-19) pandemic. (shrink)

We largely agree with Grimwade et al ’s1 conclusion that challenge trial participants may ethically be paid, including for risk. Here, we add further arguments, clarify some points from the perspective of economics and indicate areas where economists can support the development of a framework for ethically justifiable payment. Our arguments apply to carefully constructed and monitored controlled human infection model trials that have been appropriately reviewed and approved. Participants in medical studies perform a service. Outside the domain of research (...) participation, there is nearly universal agreement that workers providing a service should be compensated fairly, and that work involving more discomfort and risk should be compensated more generously. Accordingly, labour regulations impose floors, not caps on compensation. Caps, even if intended to protect against undue inducement, also raise concerns about illegal price-fixing that disadvantages workers. Such limits on payment for egg donors have successfully been challenged in court.i Moreover, caps on compensation may harm everyone at risk of infection, not just potential participants. Insufficient compensation may impede the recruitment of enough suitable subjects, for example, when representativeness of the subject sample is required. Delays in vaccine development not only prolong disruption of social, educational and economic activity but also lead to excess infections and deaths. Unlike paid CHIM participants, individuals exposed to such infection do not accept it voluntarily, are not compensated for it, and are unlikely to receive the level of medical supervision afforded to closely monitored CHIM participants. Payment caps can lead to attempts to circumvent the regulation. For example, many countries …. (shrink)

Grimwade et al highlight the current lack of a universal, standardised approach to the payment of participants taking part in controlled human infection model studies.1 As they discuss, payment for these studies is controversial, with many voicing arguments for and against higher payments, particularly for those studies which involve significant burdens to the participant. The main concerns about overpayment relate to the concepts of undue inducement or coercion, whereas underpayment raises concern about exploitation and unfair treatment. In many healthy volunteer (...) trials compensation for travel, time and inconvenience are generally accepted as fair payment, but payment for risk is less accepted, with a belief that non-therapeutic studies should only incur minimal risks, so payment for risk should not be necessary.2 This paper argues that payment for risk should be included for CHIM studies. Their findings among members of the UK public and CHIM experts from a variety of centres suggest that there is support for greater risks being associated with higher payments for participants. The amount of compensation offered by a trial has to be approved by an ethics committee/institutional review board, and some research suggests that IRB members have concerns about higher payments being offered, with only approximately one-third agreeing that payment should be offered for risk.3 Without agreement and clear guidance for calculating compensation for these types of trial, there is bound to be …. (shrink)

Controlled human infection challenge studies (CHIs) involve intentionally exposing research participants to, and/or thereby infecting them with, micro‐organisms. There have been increased calls for more CHIs to be conducted in low‐ and middle‐income countries (LMICs) where many relevant diseases are endemic. This article is based on a research project that identified and analyzed ethical and regulatory issues related to endemic LMIC CHIs via (a) a review of relevant literature and (b) qualitative interviews involving 45 scientists and ethicists with relevant expertise. (...) In this article we argue that though there is an especially strong case for conducting CHIs in endemic (LMIC) settings, certain ethical issues related to the design and conduct of such studies (in such settings) nonetheless warrant particularly careful attention. We focus on ethical implications of endemic LMIC CHIs regarding (a) potential direct benefits for participants, (b) risks to participants, (c) third‐party risks, (d) informed consent, (e) payment of participants, and (f) community engagement. We conclude that there is a strong ethical rationale to conduct (well‐designed) CHIs in endemic LMICs, that certain ethical issues warrant particularly careful consideration, and that ethical analyses of endemic LMIC CHIs can inform current debates in research ethics more broadly. (shrink)

One way to test vaccines is through human challenge trials in which participants are intentionally infected with a contagious organism to expedite the process of assessing the vaccine’s effectiveness. Some experts believe challenge trials may play an important role in fighting COVID-19, especially if the vaccines under current study do not demonstrate sufficient efficacy, if spread of COVID-19 is controlled to a point that radically slows down traditional trials, or if new vaccines need to be rapidly developed for specific subpopulations.1 (...) Challenge trials involve significant time, burden and risk, requiring participants to spend 3–6 weeks in legal quarantine for 24 hours a day in a high-security facility. During this time, no inperson visitors will be allowed, except for very limited inperson contact from researchers collecting necessary data and checks. Following the quarantine period, participants will be asked to attend numerous outpatient follow-up visits over the course of months, to further monitor their response to the vaccine. Participation involves being away from family who may themselves become sick during the global pandemic, as well as potential fear and mental anguish around being a ‘first’ subject. Because there is no definitive treatment for COVID-19, participants could experience serious illness. But even with milder illness, medical experts know very little about the long-term consequences of COVID-19 infection. This raises the question of how much people should be paid for their participation in COVID-19 challenge trials. Most think participants should be paid something, but many contend that we should be …. (shrink)

When payment is offered for controlled human infection model research, ethical concerns may be heightened due to unfamiliarity with this study design as well as perceptions—and misperceptions—regarding risk. Against this backdrop, we commend Grimwade et al 1 for their careful handling of the relevant issues, coupling empirical and conceptual approaches. We agree with foundational elements of the authors’ analysis, including the acceptability of payment for research risk.1 However, in our view, it is preferable to treat payment for risk as a (...) discretionary incentive to achieve adequate recruitment and retention, rather than compensation owed as a matter of fairness. Grimwade et al 1 note that although their ‘Payment for Risk Model’ was ‘created specifically in the context of CHIM research, it has the potential to inform payment in other areas of medical research.’ We agree and would go further: we do not need a special payment framework for CHIMs because there is nothing so novel about them compared with other types of research as to demand a distinct approach. Any successful payment framework must address the following ethical issues: preserving informed consent ; treating participants fairly ; encouraging adequate recruitment and retention; avoiding deception by participants; and preserving public trust.2 Some of these issues may have particular salience in the context of CHIMs, but this study design does not demand consideration of entirely distinct ethical factors when evaluating offers of payment.2 We also agree with Grimwade et al 1 about several other key points.2 Given the burdens involved and …. (shrink)

Human infection challenge studies (HCS) involve intentionally infecting research participants with pathogens (or other micro-organisms). There have been recent calls for more HCS to be conducted in low-income and middle-income countries (LMICs), where many relevant diseases are endemic. HCS in general, and HCS in LMICs in particular, raise numerous ethical issues. This paper summarises the findings of a project that explored ethical and regulatory issues related to LMIC HCS via (i) a review of relevant literature and (ii) 45 qualitative interviews (...) with scientists and ethicists. Among other areas of consensus, we found that there was widespread agreement that LMIC HCS can be ethically acceptable, provided that they have a sound scientific rationale, are accepted by local communities and meet usual research ethics requirements. Unresolved issues include those related to (i) acceptable approaches to trade-offs between the scientific aim to produce generalisable results and the protection of participants, (iii) the sharing of benefits with LMIC populations, (iii) the acceptable limits to risks and burdens for participants, (iv) the potential for third-party risk and whether the degree of acceptable third-party risk is different in endemic settings, (v) the conditions under which (if any) it would be appropriate to recruit children for disease-causing HCS, (v) appropriate levels of payment to participants and (vi) appropriate governance of (LMIC) HCS. This paper provides preliminary analyses of these ethical considerations in order to (i) inform scientists and policymakers involved in the planning, conduct and/or governance of LMIC HCS and (ii) highlight areas warranting future research. Insofar as this article focuses on HCS in (endemic) settings where diseases are present and/or widespread, much of the analysis provided is relevant to HCS (in HICs or LMICs) involving pandemic diseases including COVID19. (shrink)

COVID-19 poses an exceptional threat to global public health and well-being. Recognition of the need to develop effective vaccines at unprecedented speed has led to calls to accelerate research pathways ethically, including by conducting challenge studies ) with SARS-CoV-2. Such research is controversial, with concerns being raised about the social, legal, ethical and clinical implications of infecting healthy volunteers with SARS-CoV-2 for research purposes. Systematic risk evaluations are critical to inform assessments of the ethics of any proposed SARS-CoV-2 CHIs. Such (...) evaluations will necessarily take place within a rapidly changing and at times contested epidemiological landscape, in which differing criteria for the ethical acceptability of research risks have been proposed. This paper critically reviews two such criteria and evaluates whether the use of effective treatment should be a necessary condition for the ethical acceptability of SARS-CoV-2 CHIs, and whether the choice of study sites should be influenced by COVID-19 incidence levels. The paper concludes that ethical evaluations of proposed SARS-CoV-2 CHIs should be informed by rigorous, consultative and holistic approaches to systematic risk assessment. (shrink)

Global fatalities related to COVID-19 are expected to be high in 2020–2021. Developing and delivering a vaccine may be the most likely way to end the pandemic. If it were possible to shorten this development time by weeks or months, this may have a significant effect on reducing deaths. Phase II and phase III trials could take less long to conduct if they used human challenge methods—that is, deliberately infecting participants with COVID-19 following inoculation. This article analyses arguments for and (...) against such methods and provides suggested broad guidelines for regulators, researchers and ethics committees when considering these matters. It concludes that it may be possible to maintain current ethical standards yet still permit human challenge trials in a context where delay is critical. The implications are that regulators and researchers need to work together now to design robust but short trials and streamline ethics approval processes so that they are in place when applications for trials are made. (shrink)

Controlled Human Infection Model (CHIM) research involves the infection of otherwise healthy participants with disease often for the sake of vaccine development. The COVID-19 pandemic has emphasised the urgency of enhancing CHIM research capability and the importance of having clear ethical guidance for their conduct. The payment of CHIM participants is a controversial issue involving stakeholders across ethics, medicine and policymaking with allegations circulating suggesting exploitation, coercion and other violations of ethical principles. There are multiple approaches to payment: reimbursement, wage (...) payment and unlimited payment. We introduce a new Payment for Risk Model, which involves paying for time, pain and inconvenience and for risk associated with participation. We give philosophical arguments based on utility, fairness and avoidance of exploitation to support this. We also examine a cross-section of the UK public and CHIM experts. We found that CHIM participants are currently paid variable amounts. A representative sample of the UK public believes CHIM participants should be paid approximately triple the UK minimum wage and should be paid for the risk they endure throughout participation. CHIM experts believe CHIM participants should be paid more than double the UK minimum wage but are divided on the payment for risk. The Payment for Risk Model allows risk and pain to be accounted for in payment and could be used to determine ethically justifiable payment for CHIM participants.Although many research guidelines warn against paying large amounts or paying for risk, our empirical findings provide empirical support to the growing number of ethical arguments challenging this status quo. We close by suggesting two ways (value of statistical life or consistency with risk in other employment) by which payment for risk could be calculated. (shrink)