Controlled human infection models: Promises and concerns for India

Traditional vaccine trials rely on large sample populations and natural infection processes. A quicker, cheaper, but riskier method, called Controlled Human Infection Model studies (CHIMs), has also been in practice for some time. In CHIMs, volunteers are deliberately infected with a pathogen to study its effects or to test the efficacy of a vaccine. In this article, Aditi examines the science behind CHIMs and the ethical implications of legalising this method in India, where such trials are presently banned.