Are human challenge trials ethical?

India has the second-highest number of Covid-19 cases, and everyone is hoping for a vaccine. A safe and effective vaccine has to go through a rigorous safety and efficacy clearance process. The WHO Guidelines for clinical trials follow the following steps (broadly stating): Phase one, 50-100 healthy people to check safety. Phase two, 100-300 infected people for efficacy. Phase three, large and diverse healthy people (300-30000) for efficacy and side effects.

Generally, vaccine development takes years. In Phase three, the vaccine is tested on a large group of diverse people, who then go about their daily lives and are monitored. They may or may not get infected. This prolongs the trials. Because of the infectious nature of Covid-19, people are taking extra precautions and are less likely to get the virus or may take a longer time to be exposed to it. So, Phase three methods could take years.

Phase three trials could be conducted on high-risk people in densely populated areas, or healthcare workers. But since the risk is not absent, it might not be correct to test on people in densely populated areas. They live there because of larger systemic injustices. The risks could also compromise an already compromised health force.

Therefore, Human Challenge Trials (HCT) have emerged as a controversial solution. In HCT, volunteers are deliberately exposed to the virus. This shortens the time frame by eliminating the chance factor of infection. The participant’s body is ‘challenged’ by the pathogen in controlled situations.

HCTs have been conducted for diseases like malaria, dengue, etc and WHO has already published an ethical framework. The controversy in the Covid-19 vaccine is that, unlike malaria, there is no available treatment. The dilemma is ethical i.e. deliberately infecting a participant with a virus and the ability of the participant to consent to it, if done voluntarily.

Medical professionals follow the 'first do no harm' principle. So, can they infect a healthy person? The answer can be yes if we see it through the utilitarian lens. Simply put, utilitarianism means the greatest good for the greatest number. Since a large number of participants may not get infected in traditional Phase three trials, the sample size has to be extremely large. In HCT, a small number can be tested as all of them will be 100% infected. So, both the time and the number of people needed is less. The faster we can test a vaccine, the more lives we can save.

Other lenses can be altruism and choice. Many people work in high-risk professions due to their inherent altruistic tendencies. They have a need to serve others and derive value from it. Many NGOs working in conflict zones have such people working in them e.g. Doctors Without Borders (MSF). We must respect their choices. Are HCT participants different from these people?

If a person has volunteered (without any coercion, economic or otherwise), and has been informed and understands the risks, but still chooses to participate, then we can say that it is a choice made freely.

Therefore, HCT trials are probably the most ethical way to fast-track Phase three. One Day Sooner is an international movement advocating for HCT for Covid-19 vaccines. Around 36,000 people have already volunteered, showing that people will volunteer.

HCT also gains importance as the US FDA is considering granting emergency approvals for Covid-19 vaccines, and there are legitimate fears that safety standards could be reduced.

In the international vaccine race, both China and Russia are hoping to be the first to produce a commercial vaccine. Given the lack of transparency in both China and Russia, the vaccine’s viability and safety cannot be certain unless data is shared and verified.

Recently, Russia proposed to partner with India for Phase three trials for Sputnik V, which could give a confidence boost to the vaccine by making the process transparent and ethical. For this, a movement for volunteers, like the one day sooner programme can be started in India. This will ensure that the trial time is reduced ethically, and a viable vaccine can be mass-produced as the Indian pharmaceutical industry is known for quality production at a low cost. In times like these, there is no perfect solution, only a solution that is better than others.

(The writer is a Public Policy Student, Takshashila Institution)