The second Covid vaccine dose for those who took the first shot on Day 1 of inoculation drive on January 16, will be administered on February 13, the government has said. The Centre also said while the country has made remarkable progress in terms of the number of people vaccinated -- reaching the 5 million mark in Covid-19 vaccination in record 21 days -- there is "substantial scope of improvement" in the number of average vaccinations per session.