Decoded: How Covid-19 vaccine efficacy helps to get an idea of protection

With 81 per cent efficacy in the interim findings, Bharat Biotech’s Covaxin has got a shot in the arm to dispel doubts about a vaccine that is among the two being administered as part of the nationwide inoculation drive.

What is the meaning of vaccine efficacy?

Vaccinology talks about minimum essential function or the MEF of a vaccine, which includes safety and efficacy. Efficacy of a vaccine means its ability to stimulate immunity in a person who has received the shot. It is meant to significantly reduce the probability of disease — mild, moderate or severe — in a person