US Scientists to Bioengineer Coronavirus Strain for Human Challenge Trials Amid Risks

Many experts including Dr Anthony Fauci have raised questions on Human challenge trials for COVID-19 as there is no effective treatment available in case volunteers fall ill

Despite scientists and experts refuting the claims that the novel Coronavirus was not made in a Chinse lab, one in three Americans believes otherwise. But scientists in the U.S. government are manufacturing a strain of the SARS-CoV-2 in a lab that will be used in Human Challenge Trials (HCT) of vaccines.

However, the HCT will not replace the traditional clinical Phase III trials that are being conducted by Moderna and Pfizer, the U.S. National Institute of Allergy and Infectious Diseases (NIAID). Firstly, studies will be done on a small scale, keeping the volunteers in isolation units to control the spread. Then, a larger challenge trial will be done with 100 or more individuals that would require multiple locations and extensive preparations and coordination, Reuters reported.

Earlier, a group of scientists at the Washington University School of Medicine manufactured a virus that could mimic the SARS-CoV-2. However, it wasn't as infectious as the novel Coronavirus. They created the virus to help scientists in COVID-19 research using vesicular stomatitis virus (VSV).

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Human Challenge Trial offers a faster path to the development of a vaccine but raises ethical questions when there is no treatment available for a disease such as COVID-19 Reuters

Raises Questions on Ethics

Although, the aim is noble, bioengineering a strain of the virus that has already infected nearly 21 million people and killed over 750,000 will be controversial, especially the process. In human challenge trials, healthy individuals are vaccinated and then infected with the virus to test the vaccine's efficiency.

"Should there be a need for human challenge studies to fully assess candidate vaccines or therapeutics for SARS-CoV-2, NIAID has begun investigations of the technical and ethical considerations of conducting human challenge studies," the federal agency told Reuters in a statement.

Such trials are generally conducted when a virus is not in circulation anymore and there is a safety net or proven treatment in case a volunteer falls severely ill. Even Dr Anthony Fauci, Director of the U.S. NIAID, isn't in favor of such trial. He earlier said it was "not essential or ethically justified" considering there are still unknown factors involved with the virus.

HCT will also need healthy young individuals and Dr Kathleen Neuzil of the University of Maryland School of Medicine believes it will not provide the answer. "A 20-year-old in a challenge study isn't really going to give us the answer of will this vaccine keep an older person, someone with chronic kidney disease, from ending up in the hospital," said Dr Neuzil, who is also the Co-leader of the Coronavirus Vaccine Prevention Network, formed by NIAID and is testing COVID-19 vaccines.

Dr Anthony Fauci
Dr Anthony Fauci, the US NIAID Director, is also not in favor of Human Challenge Trials Wikimedia Commons

Faster Path to Vaccine Development

However, many patient advocacy groups such as 1 Day Sooner and others are in favor of the trials. Many health experts believe such trials offer a faster path to vaccine development compared to the traditional method that takes up to 15 years. At a virtual summit, hosted by the Indian Council of Medical Research, many experts, who are involved in vaccine research and development, differed with Dr Fauci.

"Human challenge trials have a major role in developing a vaccine to help quickly evaluate which vaccines generate immune responses and also helps in comparing vaccine head to head," Dr Stanley Plotkin, Emeritus Professor, University of Pennsylvania, said.

NIAID Under Pressure

With the pandemic still out of control, a vaccine is probably the only answer in combating the virus. Though its director is not in favor of HCT trials, NIAID has agreed to conduct them insisting that the priority will be to conduct traditional field trials to COVID-19 vaccine candidates. The statement comes after some drug makers advocated for HCT. Johnson & Johnson and AstraZeneca have voiced consent in favor of the controversial trials.

Around 100 healthy individuals will be infected with the bio-engineered strain of the Coronavirus for human challenge trials (representational image) Xinhua/IANS

Johan Van Hoof, Global Vaccines Chief of Johnson & Johnson argued that HCT was being conducted in many countries and the company too was following their preparations. He added that the company would only go forward with HCT if there is an effective treatment available and ethical questions are answered. Previously, HCTs have been conducted for yellow fever, influenza, typhoid, cholera, and malaria.

Earlier, in an open letter, around 125 academicians, doctors, epidemiologists and scientists including 15 Nobel laureates urged for HCT to produce a vaccine urgently and curb the spread of the Coronavirus pandemic.

"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 letter read.

Related topics : Coronavirus