More than 87,000 people across the country have been reported as Covid positive after the second vaccination dose, while 46 percent of those cases are from Kerala.
Kerala reported close to 80,000 Covid cases after the first vaccination dose. In contrast, 40,000 people were reported to be infected after the second dose, the sources said.
The increase in infections in the state, which has seen a rise in daily cases, has become a concern for the Union Ministry of Health.
Some 200 samples of advanced infections have been genomically sequenced. Still, no mutation or variant has been found so far, the sources added.
A mutation always drives a new wave of infection, as seen during the devastating and virulent second wave of Covid earlier this year, when the Delta variant of the virus had been dominant.
Since the second wave has been in decline, the authorities have been alert about the possibility of the appearance of new variants.
Breakthrough cases have also been reported in Wayanad, which has a 100% vaccination rate.
Kerala, the state that conveys the most daily infections, reported 21,427 cases and 179 deaths from Covid today.
The center also closely monitors the neighboring states of Karnataka and Tamil Nadu.
Efforts are underway to perform genome sequencing in these states.