New Delhi, Oct. 8 -- There are many who believe that with the discovery of a vaccine, all the problems related to the covid pandemic will be solved once and for all. So far, all the measures taken were only to slow the spread of the virus. News of the development of a usable vaccine, a clear preventive solution, will be a relief for everyone. But there is a problem. It could set in motion new problems of human behaviour.

Until now, there existed a sense of vulnerability about the virus. Although a small segment of people refused to wear masks and maintain social distance, the majority displayed caution and obeyed regulations. But perceptions of risk are not constant.

Individuals behave more cautiously if they perceive greater risk or da...