Vaccine Development for COVID 19: Human Challenge Trials are becoming controversial

What are human challenge trials? Why are they controversial?

How are vaccines usually developed?

What are the ethical concerns associated with Human Challenge Trials for Vaccine Development?

UPSC Can list these Questions under

GS paper 2 (Issues related to health, education and human resources)

What is the context about?

As of April 27, a global initiative called 1DaySooner had registered 3,817 people in 52 countries who had signed up for human challenge trials.

What are human challenge trials? Why are they controversial?

  • As laboratories around the world race to develop a vaccine for the novel coronavirus, many people have volunteered to take part in a controversial testing method called human challenge trials.
  • The method, which involves intentionally infecting volunteers with the novel coronavirus, is being promoted in order to “speed up” the process of preparing a vaccine.

How are vaccines usually developed?

In most regulatory regimes, vaccines take several years to develop, and their development typically proceeds through three phases of clinical trials.

  • In Phase 1, small groups of people receive the trial vaccine.
  • During Phase 2, the clinical study is expanded and the vaccine is given to people who have characteristics (such as age and physical health) similar to those for whom the new vaccine is intended.
  • In Phase 3, the vaccine is given to several thousand people and tested for efficacy and safety.
  • During this phase, participants either receive the vaccine or a placebo.
  • The efficacy of the vaccine is determined by comparing the prevalence of infection in the group, that was administered the vaccine with the one which received a placebo.
  • The hypothesis that those in the vaccine group will be infected significantly less is thus tested.

What are the ethical concerns associated with Human Challenge Trials for Vaccine Development?

  • While human challenge trials are not new, they are usually carried out in developing medications for diseases which are considered less lethal and have been better understood by scientists over the years, such as malaria.
  • Critics have questioned undertaking such trials for Covid-19, a potentially deadly disease for even those who are less at risk, and which researchers are still in the early stages of studying.