Even though results published by early phases of the trials show a favourable outcome among volunteers, regulators still require drug candidates to undergo more mandatory testing. This will ultimately evaluate if the treatment would be safe and effective against SARS-CoV-2. One hurdle that could mean more delays is that researchers have to wait for subjects to be naturally exposed to the virus. However, the National Institute of Allergy and Infectious Diseases (NIAID) could be considering the approval of a controversial procedure.

While there have been promising developments in the past few weeks related to COVID-19 vaccines, experts warn against complacency. In the meantime, the U.S. Centers for Disease Control and Prevention (CDC), as well as the World Health Organization (WHO), continue to urge people to follow established precautionary guidelines.

A week ago, top specialists noted that US president, Donald Trump's claims of coronavirus inoculations being available by Election Day are highly unlikely. Moreover, the majority forecast that it is likely possible in 2021 instead of this year. As such, the NIAID Director Dr. Anthony Fauci revealed that healthcare officials might eventually consider human challenge trials in a worst-case scenario.

Scientists of the federal agency are now reportedly developing a specific strain the 2019 novel coronavirus for the proposed contingency measure, reports CNN. According to Fauci, the proposal is currently identified as "Plan D" and it is currently in its earliest stages. He stated: "We're taking preliminary steps." The government contract might have already been awarded or could be announced soon to confirm which company will produce the strain in question.

Nevertheless, the NIAID director pointed out that as much as possible human challenge trials are an "absolutely far out contingency." "Quite frankly, I don't think this is something we're going to use.," he added. The manufacturer will likely be required to ensure that it passes "Good Manufacturing Practice" (GMP) requirements.

Dr Anthony Fauci
The widely respected health expert Doctor Anthony Fauci was not invited. Photo: POOL / Al Drago

What this means is the strain developed should meet the "aspect of quality assurance that ensures that medicinal products are consistently produced and controlled to the quality standards appropriate to their intended use and as required by the product specification," as detailed by the WHO. Leading experts around the world have been calling for the approval of human challenge trials.