Social distancing went for a toss as thousands thronged immunisation centres across the capital on Thursday to take their second Covid vaccine shots. In the Lalbag area, for instance, UNB found that health workers were literally struggling to manage large crowds. Many people who came to the centres in the area neither wore masks nor followed social distancing rules. Read: 2nd doses to be administered under mass vaccination on 3 days in cities, 1 day outside cities: PMO