"There's a concern among the highest quarters of an impending vaccine hesitancy, in view of most taking a single dose already and disease incidence at its lowest," said one of the sources, both of whom declined to be identified.
Large numbers of people skipping their second dose would be particularly problematic in areas with low numbers of previously infected people, meaning more people with fewer antibodies so those communities would be more vulnerable, the first expert said.
The second expert said the health ministry had told states to encourage people to get their second doses as soon as possible, so on the 12th week after their first dose, rather than waiting for the latest date, in a bid to ensure people don't miss the second shot.