Two days to go for the rollout of the Covid vaccines, the Centre circulated the dos and don'ts for vaccination to the states this evening. The rollout on Saturday is expected to cover 3 lakh healthcare workers across 3,006 sites across the country. Vaccination is allowed only for those who are above the age of 18 years, the Centre said. Women who are pregnant or not sure of their pregnancy and lactating mothers should not receive the vaccine.