The Problems With One-Dose Covishield If Covishield is administered as a single-dose vaccine, a small study found its efficacy against symptomatic COVID-19 caused by the B.1.617.2 variant is only 33%. Photo: Artem Podrez/Pexels Health4 hours ago On May 31, NDTV quoted unnamed sources in the Indian government saying it will be conducting a study to assess the feasibility of deploying the Covishield vaccine in a single-dose regimen instead of continuing the extant double-dose regimen. At any other time, such a statement may have been sufficient to believe the government would organise and conduct a well-designed trial, publicise the findings and revise policy (or not) to stay in line with the findings, informed by socio-economic considerations. But the last 15 months have thrown up enough incidents of public-health malpractice on the state’s part to make such hope foolish. There is a nontrivial chance, especially if the vaccine shortage persists and the outbreaks on an upward trajectory in some parts of the country at the moment aren’t tamped down quickly, that the government is going to conduct a trial, not publish its methods and findings and push through a policy to deploy Covishield as a single-dose shot.