The government on Thursday said that Maharashtra, West Bengal, Tamil Nadu, Delhi, Karnataka and Gujarat are emerging as states and UTs of concern on the basis of weekly Covid -19 cases and positivity rate.

It said that eight districts are reporting over 10 per cent weekly positivity, while 14 districts are reporting between 5-10 per cent positivity.

India's R naught value, which indicates spread of Covid -19, is 1.22 so cases are increasing, not shrinking, the government said.

The country has reported more than 10,000 daily new Covid -19 cases after 33 days, it said stressing that there is a need for heightened vigil in view of sharp increase in infections.

Evidence shows that omicron variant has a growth advantage over Delta with doubling time of 2-3 days, the government said quoting the WHO.

It said the durability of immunity post COVID-19 infection persists for about 9 months.

The government said 90 per cent of India's adult population has been administered the first dose of the coronavirus vaccine and 63.5 per cent people are now fully vaccinated.

The precautionary dose of the vaccine is primarily to mitigate severity of infection, hospitalisation and death, it said.

The government said that masking before and after vaccination is a must. It said that earlier and currently circulating strains of coronavirus spread through the same routes and added that treatment guidelines for the infection remain the same.

It said that the whole virus infects an individual in natural settings and added that it elicits cell mediated immunity and immunological memory.

The government said that within one month 3,30,379 cases of omicron variant and 59 deaths were reported across 121 countries.