Wanted: 64 volunteers willing to be reinfected for Oxford Covid-19 study

People who have fought off Covid-19 will be deliberately reinfected in a first-of-its-kind trial at the University of Oxford that may shed light on how to develop more effective vaccines against the pathogen.

Researchers are looking for 64 healthy, previously Covid-infected volunteers from 18 to 30 years old to be studied under controlled, quarantined conditions for at least 17 days, the UK university said Monday. Participants will be infected with the original strain from Wuhan, China and followed for a year.

Initial data from the Oxford study should be available within several months, helping vaccine developers look at levels and types of immunity needed to prevent reinfection, and how long protection persists. Challenge trials, involving deliberate, supervised infections, are seen as particularly helpful for answering questions like these, because they allow scientists to scrutinise the details of how the body confronts the virus and vice versa.

While vaccines and previous infections provide some immune protection against the coronavirus, concerns and doubts remain about how long it lasts. A recent study indicated that as much as 10 per cent of previously infected young adults were reinfected, underscoring the need for effective vaccines to prevent spread, and Pfizer’s chief executive officer has said that booster shots may be needed to maintain the immunity provided by the initial two doses of the company’s shot.

The Oxford study “has the potential to transform our understanding by providing high-quality data on how our immune system responds to a second infection,” said Shobana Balasingam, a research adviser at the Wellcome Trust, which is providing funds. The findings could “inform not just vaccine development but also research into the range of effective treatments that are also urgently needed”.

One of the goals of the study is to determine how much virus, on average, it takes to infect someone who’s had the virus earlier. In a second phase of the study, a different group of patients will be given that dose and studied for their immune responses, Oxford said.