Reports said quoting sources that the AstraZeneca vaccine was initially planned as a single-shot jab but it was finalised as a two-dose vaccine following studies on its effectiveness. NK Arora, chairman of the COVID-19 working group under the National Technical Advisory Group on Immunization (NTAGI), said it was being deliberated upon whether a single shot will provide enough protection. According to sources, there is a view in the government that Covishield should also work as a single-dose vaccine as other jabs based on a similar platform like the Sputnik V Light and Johnson & Johnson’s Janssen vaccines are also administered in a single dose.