The social and ethical issues surrounding controlled human infection studies are particularly complex; study participants do not benefit from the research themselves, so it’s imperative that recruitment and participation are robustly scrutinised from an ethical perspective.

Characterising potential ethical issues for human infection studies can be partly informed by theory, for example, using existing ‘traditional’ framings of research ethics and the existing literature on human infection studies. There is also a need to develop a grounded understanding of ethical issues, taking the specific context of a planned study into consideration. While social science and community engagement/involvement are different fields of activity, these approaches can work together in important ways to build this grounded understanding.

This section acts as a brief overview of the contribution of community engagement and involvement (CEI) and social science to ethics in controlled human infection studies, as a guide to the links to resources for more information on each.  


Community engagement and involvement (CEI)

CEI generally isn’t a research activity, but encompasses approaches that support research and the fair involvement of communities. Engagement and involvement activities draw on a wide range of methods and include diverse stakeholders, depending on the aims of engagement/involvement (ref). They most typically include study participants and the communities where they live, but may also include wider contributions (such as from health policy makers and providers).  

Across the literature, there is a general agreement that CEI should aim to:

  • Assess and, where possible, build community acceptability of a proposed study, including through adaptations to the study or the site.
  • Evaluate and strengthen ethical conduct within the study, including through adapting these to local needs. For example, community engagement can help to minimise risks of undue inducement and strengthen informed consent.
  • Underpin a commitment to mutual respect, benefit sharing and building trust, including through the development of collaborative partnerships.


Social science and CEI: a combined approach

 Social science is a broad research tradition in which structural influences (including political, social, economic and historical issues) are considered alongside individual influences. Social science methods (qualitative and quantitative) have been widely used in empirical forms of ethics research.

Social science research and CEI are different approaches to understanding and responding to ethical issues in research, but can be highly complementary. Bringing them together may be a particularly powerful way of exploring ethical issues in complex forms of research, including human infection studies. For example, deliberative approaches to engaging publics or communities in ethical issues for policy and practice have been well described internationally. Practical examples have been published using approaches of ‘town hall conferences’ and ‘citizens’ assemblies’.

Applying a social science approach to CEI activities generates opportunities to:

  • Widen the transferability of findings compared to typical CEI approaches.
  • Strengthen accountability (and therefore policy support) of the findings by using a systematic approach to data collection and analysis.
  • Examine structural influences on ethical issues for human infection challenges studies, including through the involvement of groups who are marginalised or otherwise excluded.


‘Traditional’ framings of research ethics

The Nuremberg Code (1947)

Declaration of Helsinki

International Ethical Guidelines for Health-related Research Involving Humans (CIOMS)

What Makes Clinical Research in Developing Countries Ethical? The Benchmarks of Ethical Research (Emanuel et al, 2004)


Existing literature from human infection studies

Key criteria for the ethical acceptability of COVID-19 human challenge studies (WHO, 2020)

Ethical Criteria for Human Challenge Studies in Infectious Diseases (Bambery et al, 2016) 

Ethical Considerations in Controlled Human Malaria Infection Studies in Low Resource Settings: Experiences and Perceptions of Study Participants in a Malaria Challenge Study in Kenya (Njue et al, 2018)