Fauci says human challenge trials not ethically justified, experts disagree – ET HealthWorld

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Fauci says human challenge trials not ethically justified, experts disagree - ET HealthWorld

Dr. Anthony Fauci (AP Photo)

US infectious diseases expert Anthony Fauci on Thursday said, that conducting human challenge studies are “not essential or ethically justified” at the moment as the full health impact of SARS-Cov2 infection is not yet fully understood and we have no highly effective therapies that are available to cure individuals who are infected in a challenge study.

Fauci who is the Director of National Institute of Allergy and Infectious Diseases and one of the lead members of the Coronavirus Task Force in the US was addressing Indian Council of Medical Research’s international symposium on Novel Ideas in Science and Ethics of Vaccines Against Covid-19 Pandemic.

In a human challenge trial (HCT) participants of both the vaccine group and the placebo group upon consent are deliberately infected with the virus. Currently, only human trials are being conducted in which the volunteers are not purposely exposed to the virus.

Agreeing with Fauci’s views on HCTs, Peter Piot, Director, London School of Hygiene and Tropical Medicine, UK, who himself battled the painful experience of Covid-19 for 4 months said, “don’t wish this disease on anybody.”

Globally, the coronavirus pandemic infected 17.3 million people and around 6 lakh died from the disease. With the rising awareness on the need to curb the spread of Covid-19, more and more people are volunteering to be vaccine candidates to accelerate the development of the vaccine.

At the ICMR virtual event, many global experts who are involved in vaccine development and distribution disagreed with Fauci’s statement opposing human challenge trials.

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

Previously, HCTs have contributed to the development of vaccines for yellow fever, influenza, typhoid, cholera, and malaria.

While speaking in the favour of conducting HCTs for coronavirus, Adrian Hill, Director of the Jenner Institute and professor of Human Genetics, University of Oxford said, “This (HCTs) has been done for other viruses like malaria and cholera without any problems, so I don’t see why we cannot do this for Covid-19.”

Hill added that patient safety can be ensured by putting in place protocol for conducting such studies.

According to a report in The Guardian, the Jenner Institute, which is working collaboratively on developing the promising vaccine candidate from the University of Oxford, is considering such challenge trials to expedite results.

Currently, all four companies namely AstraZeneca, Johnson & Johnson, Pfizer and Moderna which are considered as the frontrunners are carrying out human trials for their vaccines against the novel coronavirus.

A standard vaccine development takes 10-15 years. Human challenge trials can fasten up this process. A reason why experts are asking for replacing Phase III trials with HCT.

Earlier, for addressing the urgent need of the vaccine to curb the coronavirus pandemic, about 125 academicians, doctors, epidemiologists, scientists, and professors, including 15 Nobel laureates wrote an open letter asking for human challenge trials to be conducted.

“If challenge trials can safely and effectively speed the vaccine development process, there is a formidable presumption in favour of their use, which would require a very compelling ethical justification to overcome,” they wrote.

In HCT the virus is exposed to young and healthy adults who have developed antibodies from the vaccines and are under strict laboratory conditions and restrictions. This directly tells us whether the vaccine works or not unlike in the case of human clinical trials.

Marc Lipsitch, Professor of Epidemiology and Director, Center for Communicable Disease Dynamics, Harvard T.H. Chan School of Public Health, USA, emphasised that while it is important to not compromise on safety for speed, he believed that human challenge trial is a potential adjunct for understanding the impact of infection shedding and distribution of vaccines within and between countries.

Safety of patients is crucial. Volunteers must ethically give informed consent to HCTs and should be fully informed of the risks, monitored closely, and should they contract an infection, be given the best possible care.

HCT remains to be controversial as it involves infecting volunteers with the virus which currently does not have a cure, proven treatment and no information of its long term impact. There is no reduced risk of severity of the disease or even death.

Coronavirus initially appeared to impact only the lungs, but now there are evolving studies that explain how the virus also affects the heart, blood vessels, kidneys, gut and brain. If results don’t turn unfavourable, there is also a risk of further losing trust in vaccination.

“Human challenge trials were never conducted in India but the government has been discussing the ethics around it in the context of Covid-19,” said Gagandeep Kang, who recently retired as the executive director of the Translational Health Science and Technology Institute. She also agreed on being careful as the sequelae of Covid-19 infection is not fully known.

Balram Bhargava, Director General, ICMR, concluded by mentioning the four major challenges once a safe and effective vaccine is developed. He said, “One is prioritising fair distribution to vulnerable groups, second is logistics of vaccine rollout, third is stockpiling and fourth is training people who will administer the vaccine.”

He believes that if all communities unite as one we can overcome this pandemic.

Currently, India is conducting Phase I trials of the Covid-19 vaccine developed by Bharat Biotech, in collaboration with the ICMR in 12 centres across the country.

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