Enlarge / Woman receives an experimental COVID-19 vaccine at the University of Massachusetts Medical School in Worcester, MA, on September 04, 2020, as part of a clinical trial. (credit: Getty | Boston Globe) Researchers in the United Kingdom plan to begin intentionally infecting a small batch of healthy young people with the novel coronavirus in January as part of a first “human challenge trial,” according to an announcement Monday. The plan has not yet been approved by the Medicines and Healthcare Regulatory Agency (MHRA), which regulates clinical trials in the UK, and outside experts have had mixed reactions to the announcement so far. Nevertheless, the UK government is planning to invest $43.4 million (33.6 million pounds) in the trials.