Covid was back at the centre of India’s health and political map on Wednesday with the government advising people to get vaccinated and mask up, and saying random sample testing will be conducted at airports for passengers arriving from China and other countries. Three cases of the Omicron subvariant BF.7, apparently the strain driving China's current surge of Covid cases, were detected. The first case of BF.7 in India was detected in October by the Gujarat Biotechnology Research Centre, official sources said, adding that two cases have been reported from Gujarat and one from Odisha.