London (CNN) More than 100 top scientists including 15 Nobel laureates have written an open letter calling for volunteers to be exposed to the coronavirus to assist with vaccine development. They said so-called "human challenge trials" or "controlled infection trials" were of "vast importance" in speeding up the testing of the vaccines in development around the world. "If challenge trials can safely and effectively speed the vaccine development process, there is a formidable presumption in favor of their use, which would require a very compelling ethical justification to overcome," the scientists wrote in the letter to Dr. Francis Collins, director of the US National Institutes of Health (NIH). It urged the US government to undertake immediate preparations for human challenge trials, "including supporting safe and reliable production of the virus and any biocontainment facilities necessary to house participants." The letter said human challenge trials -- in which volunteers are deliberately exposed to the pathogen under controlled conditions -- can provide information months before conventional efficacy trials, in which candidates receive a vaccine or control and resume their normal life, with the assumption that they may be eventually exposed to the virus.

Source: CNN July 16, 2020 13:07 UTC