HO convened an Advisory Group (AG) to consider the feasibility, potential value, and limitations of establishing a closely?monitored challenge model of experimental severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coro?navirus disease 2019 (COVID-19) in healthy adult volunteers. The AG included experts in design, establishment, and performance of challenges. This report summarizes issues that render a COVID-19 model daunting to establish (the potential of SARS-CoV-2 to cause severe/fatal illness, its high transmissibility, and lack of a “rescue treatment” to prevent progression from mild/moderate to severe clinical illness) and it proffers prudent strategies for stepwise model development, challenge virus selection, guidelines for manufacturing challenge doses, and ways to contain SARS-CoV-2 and prevent transmission to household/community contacts. A COVID-19 model could demonstrate protection against virus shedding and/or illness induced by prior SARS-CoV-2 challenge or vaccination. A limitation of the model is that vaccine efficacy in experimentally challenged healthy young adults cannot per se be extrapolated to predict efficacy in elderly/high-risk adults.

31st March 2021 • 0 comments

This article discusses the science behind herd immunity and the important role that vaccinations play in ensuring that herd immunity can be achieved.

11th November 2020 • 0 comments

This article, published in The Lancet Infectious Diseases, presents the ethical issues associated with human challenge studies and COVID-19. 

24th September 2020 • 0 comments
20th August 2020 • 0 comments

The third coronavirus outbreak in the past 20 years, the SARS-CoV-2 pandemic has caused unprecedented morbidity, mortality, and economic disruption. Safe, effective, and deployable SARS-CoV-2 vaccines are urgently needed to mitigate the consequences of the pandemic and protect from future outbreaks. The accelerated response to Covid-19 includes investments in preclinical and clinical testing and manu- facture of multiple vaccine candidates, with efficacy trials in the United States anticipated to start in July 2020.

6th July 2020 • 0 comments
31st March 2020 • 0 comments

Ethical considerations for human infection studies: experiences and perceptions of study participants in Kenya

by M. Njue, P. Njuguna, M. Kapulu, G. Sanga, P. Bejon, V. Marsh, S. Molyneux, D. Kamuya
5th February 2020 • 0 comments