It is obviously difficult to initiate and rapidly enrol people in prospective double-blinded randomized clinical trials of treatments during a rapidly evolving pandemic (see Nature 593, 182–185; 2021) — particularly when extremely effective vaccines are available. But we still need therapeutics. Vaccinations do not give immediate or 100% protection and could be undermined by resistant strains.
The United States is fast losing treatment and control groups as more and more of the population are vaccinated. But not all countries are so fortunate. In India, where the disease is still exploding, treatments could save countless lives.
Worldwide, this is a fundamental scientific and social issue. We must find ways to rapidly set up rigorous prospective clinical trials in places where the vaccine could arrive too late — and to run such trials in health-care systems that are already pushed to the brink.