AbstractDuring the Covid-19 pandemic, ethicists and researchers proposed human challenge studies as a way to speed development of a vaccine that could prevent disease and end the global public health crisis. The risks to healthy volunteers of being deliberately infected with a deadly and novel pathogen were not low, but the benefits could have been immense. This essay is a history of the three major efforts to set up a challenge model and run challenge studies in 2020 and 2021. The (...) pharmaceutical company Johnson and Johnson, the National Institutes of Health in the United States, and a private-public partnership of industry, university, and government partners in Britain all undertook preparations. The United Kingdom’s consortium began their Human Challenge Programme in March of 2021.Beyond documenting each effort, the essay puts these scientific and ethical debates in dialogue with the social, epidemiological, and institutional conditions of the pandemic as well as the commercial, intellectual, and political systems in which medical research and Covid-19 challenge studies operated. It shows how different institutions understood risk, benefit, and social value depending on their specific contexts. Ultimately the example of Covid-19 challenge studies highlights the constructedness of such assessments and reveals the utility of deconstructing them retrospectively so as to better understand the interplay of medical research and research ethics with larger social systems and historical contexts. (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)

To counter the pandemic caused by severe acute respiratory syndrome coronavirus 2, some have proposed accelerating SARS-CoV-2 vaccine development through controlled human infection trials. These trials would involve the deliberate exposure of relatively few young, healthy volunteers to SARS-CoV-2. We defend this proposal against the charge that there is still too much uncertainty surrounding the risks of COVID-19 to responsibly run such a trial.

Weighing competing obligations and achieving the “greatest balance” of right over wrong guides an individual, an agency or a country in determining what ought to be done in an ethically challenging situation. Conducting controlled human infection model (CHIM) studies in India is one such situation. The ethical challenge in conducting a CHIM study lies in completing the difficult task of introducing standardised, attenuated strains of micro-organisms into normal healthy volunteers, at the same time ensuring the safety of these healthy individuals (...) from potential and completely informed risks in a fashion that is transparent and accountable. The bar is further raised against the background of already fragile public confidence in biomedical research in India; especially when “deliberate” introduction of microbial agents into healthy individuals is involved, with the larger altruistic objective of gain to society as a whole. -/- This paper discusses the uses of CHIM studies with respect to the larger scientific Indian research enterprise of the 21st century. It further explores etic and emic perspectives in conducting such trials in India and seeks to generate an ethical coherence to the justification for conducting CHIM studies in India. The paper deliberates on ethical issues arising out of conducting CHIM studies and reflects on how developing the capacity for CHIM studies in India is likely to strengthen the health research and development sector in the country. -/- . (shrink)

A number of papers have appeared recently arguing for the conclusion that it is ethically acceptable to infect healthy volunteers with severe acute respiratory syndrome coronavirus 2 as part of research projects aimed at developing COVID-19 vaccines or treatments. This position has also been endorsed in a statement by a working group for the WHO. The papers generally argue that controlled human infection is ethically acceptable if the risks to participants are low and therefore acceptable, the scientific quality of the (...) research is high, the research has high social value, participants give full informed consent, and there is fair selection of participants. All five conditions are necessary premises in the overall argument that such research is ethically acceptable. The arguments concerning risk and informed consent have already been critically discussed in the literature. This paper therefore looks specifically at the arguments relating to condition 3 ‘high social value’ and condition 5 ‘fair selection of participants’ and shows that whereas they may be valid, they are not sound. It is highly unlikely that the conditions that are necessary for ethical CHI trials to take place will be fulfilled. Most, if not all, CHI trials will thus be well intentioned but unethical. (shrink)

BackgroundHuman infection studies (HIS) are valuable in vaccine development. Deliberate infection, however, creates challenging questions, particularly in low and middle-income countries (LMICs) where HIS are new and ethical challenges may be heightened. Consultation with stakeholders is needed to support contextually appropriate and acceptable study design. We examined stakeholder perceptions about the acceptability and ethics of HIS in Malawi, to inform decisions about planned pneumococcal challenge research and wider understanding of HIS ethics in LMICs.MethodsWe conducted 6 deliberative focus groups and 15 (...) follow-up interviews with research staff, medical students, and community representatives from rural and urban Blantyre. We also conducted 5 key informant interviews with clinicians, ethics committee members, and district health government officials.ResultsStakeholders perceived HIS research to have potential population health benefits, but they also had concerns, particularly related to the safety of volunteers and negative community reactions. Acceptability depended on a range of conditions related to procedures for voluntary and informed consent, inclusion criteria, medical care or support, compensation, regulation, and robust community engagement. These conditions largely mirror those in existing guidelines for HIS and biomedical research in LMICs. Stakeholder perceptions pointed to potential tensions, for example, balancing equity, safety, and relevance in inclusion criteria.ConclusionsOur findings suggest HIS research could be acceptable in Malawi, provided certain conditions are in place. Ongoing assessment of participant experiences and stakeholder perceptions will be required to strengthen HIS research during development and roll-out. (shrink)

The COVID-19 pandemic touched off an unprecedented search for vaccines and treatments. Without question, the development of vaccines to prevent COVID-19 was an enormous scientific accomplishment. Further, the RECOVERY and Solidarity trials identified effective treatments for COVID-19. But all was not success. The urgent need for COVID-19 prevention and treatment fueled an embrace of risks—to research participants and to the reliability of the science itself—as allegedly necessary costs to speed scientific progress. Scientists and (even) ethicists supported overturning longstanding norms protecting (...) healthy volunteers in human challenge trials to speed vaccine development, but these trials led to no vaccines. Physicians, with the approval of research ethics committees, designed hundreds of unblinded, single-center clinical trials at high risk of bias to speed the identification of new treatments. But these clinical trials led to no treatments. The lesson for future pandemics is that the acceptance of greater risks to participants or science does not reliably lead to progress. We are better served by science that upholds the highest ethical and methodological standards. (shrink)

Mandatory vaccination, including for COVID-19, can be ethically justified if the threat to public health is grave, the confidence in safety and effectiveness is high, the expected utility of mandatory vaccination is greater than the alternatives, and the penalties or costs for non-compliance are proportionate. I describe an algorithm for justified mandatory vaccination. Penalties or costs could include withholding of benefits, imposition of fines, provision of community service or loss of freedoms. I argue that under conditions of risk or perceived (...) risk of a novel vaccination, a system of payment for risk in vaccination may be superior. I defend a payment model against various objections, including that it constitutes coercion and undermines solidarity. I argue that payment can be in cash or in kind, and opportunity for altruistic vaccinations can be preserved by offering people who have been vaccinated the opportunity to donate any cash payment back to the health service. (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)

Human infection challenge studies (HCS) have been proposed as a means to accelerate SARS-CoV2 vaccine development and thereby help to mitigate a prolonged global public health crisis. A key criterion for the ethical acceptability of SARS-CoV2 HCS is that potential benefits outweigh risks. Although the assessment of risks and benefits is meant to be a standard part of research ethics review, systematic comparisons are particularly important in the context of SARS-CoV2 HCS in light of the significant potential benefits and harms (...) at stake as well as the need to preserve public trust in research and vaccines. In this paper we explore several considerations that should inform systematic assessment of SARS-CoV-2 HCS. First, we detail key potential benefits of SARS-CoV-2 HCS including, but not limited to, those related to the acceleration of vaccine development. Second, we identify where modelling is needed to inform risk-benefit (and thus ethical) assessments. Modelling will be particularly useful in (i) comparing potential benefits and risks of HCS with those of vaccine field trials under different epidemiological conditions and (ii) estimating marginal risks to HCS participants in light of the background probabilities of infection in their local community. We highlight interactions between public health policy and research priorities, including situations in which research ethics assessments may need to strike a balance between competing considerations. (shrink)

Valid consent requires the potential research participant understands the information provided. We examined current practice in 50 proposed Clinical Trials of Investigational Medicinal Products to determine how this understanding is checked. The majority of the proposals ( n = 44) indicated confirmation of understanding would take place during an interactive conversation between the researcher and potential participant, containing questions to assess and establish understanding. Yet up until now, research design and review have not focussed upon this, concentrating more on written (...) material. We propose ways this interactive conversation can be documented, and the process of checking understanding improved. (shrink)

Issues related to controlled human infection studies using Schistosoma mansoni (CHI-S) were explored to ensure the ethical and voluntary participation of potential CHI-S volunteers in an endemic setting in Uganda. We invited volunteers from a fishing community and a tertiary education community to guide the development of informed consent procedures. Consultative group discussions were held to modify educational materials on schistosomiasis, vaccines and the CHI-S model and similar discussions were held with a test group. With both groups, a mock consent (...) process was conducted. Fourteen in-depth key informant interviews and three group discussions were held to explore perceptions towards participating in a CHI-S. Most of the participants had not heard of the CHI-S. Willingness to take part depended on understanding the study procedures and the consenting process. Close social networks were key in deciding to take part. The worry of adverse effects was cited as a possible hindrance to taking part. Volunteer time compensation was unclear for a CHI-S. Potential volunteers in these communities are willing to take part in a CHI-S. Community engagement is needed to build trust and time must be taken to share study procedures and ensure understanding of key messages. (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)

The Covid-19 pandemic creates an unprecedented threatening situation worldwide with an urgent need for critical reflection and new knowledge production, but also a need for imminent action despite prevailing knowledge gaps and multilevel uncertainty. With regard to the role of research ethics in these pandemic times some argue in favor of exceptionalism, others, including the authors of this paper, emphasize the urgent need to remain committed to core ethical principles and fundamental human rights obligations all reflected in research regulations and (...) guidelines carefully crafted over time. In this paper we disentangle some of the arguments put forward in the ongoing debate about Covid-19 human challenge studies (CHIs) and the concomitant role of health-related research ethics in pandemic times. We suggest it might be helpful to think through a lens differentiating between risk, strict uncertainty and ignorance. We provide some examples of lessons learned by harm done in the name of research in the past and discuss the relevance of this legacy in the current situation. (shrink)

Zika virus was recognised in 2016 as an important vector-borne cause of congenital malformations and Guillain-Barré syndrome, during a major epidemic in Latin America, centred in Northeastern Brazil. The WHO and Pan American Health Organisation, with partner agencies, initiated a coordinated global response including public health intervention and urgent scientific research, as well as ethical analysis as a vital element of policy design. In this paper, we summarise the major ethical issues raised during the Zika epidemic, highlighting the PAHO ethics (...) guidance and the role of ethics in emergency responses, before turning to ethical issues that are yet to be resolved. Zika raises traditional bioethical issues related to reproduction, prenatal diagnosis of serious malformations and unjust disparities in health outcomes. But the epidemic has also highlighted important issues of growing interest in public health ethics, such as the international spread of infectious disease; the central importance of reproductive healthcare in preventing maternal and neonatal morbidity and mortality; diagnostic and reporting biases; vector control and the links between vectors, climate change, and disparities in the global burden of disease. Finally, there are controversies regarding Zika vaccine research and eventual deployment. Zika virus was a neglected disease for over 50 years before the outbreak in Brazil. As it continues to spread, public health agencies should promote gender equity and disease control efforts in Latin America, while preparing for the possibility of a global epidemic. (shrink)

Pox parties are a controversial alternative to vaccination for diseases such as chickenpox. Such parties involve parents infecting non-immune children by exposing them to a contagious child. If successful, infection will usually lead to immunity, thus preventing infection later in life, which, for several vaccine-preventable diseases, is more severe than childhood infection. Some may consider pox parties more morally objectionable than opting out of vaccination through non-medical exemptions. In this paper, I argue that this is not the case. Pox parties (...) involve immediate risk of harm for children and reduce future harms, whereas opting out of vaccination places children at long-term risk of harms that increase with time, at least for some pathogens. Regarding harm to others through onward transmission of infection, this can be easily prevented in the case of pox parties—given the relatively controlled timing of infection—by quarantining attendees after the party, whereas opting out of vaccination involves risks to others that are more difficult to control. I defend three criteria for an ethical pox party: (1) that the disease is sufficiently low risk, (2) that parents consent to their child’s attendance and (3) that children exposed to infection are quarantined and isolated appropriately. I argue that, if these criteria are met, pox parties are morally preferable to non-vaccination; such parties involve less risk to non-consenting others and, for some pathogens in some cases, even involve less risk for the children who participate. Thus, policies that permit non-medical exemption to vaccination should also permit ethical pox parties. Alternatively, if pox parties are not permitted, then vaccination should be mandated for those without medical contraindication. (shrink)