Many people who had booked their vaccination slots at select Calcutta Municipal Corporation facilities through a WhatsApp chatbot for Thursday learnt that jabs would not be administered during the day only after they arrived at the centres.

The recipients said they did not get any message on cancellation of vaccination. A CMC official said the information was posted on the social media pages of the civic body.

“Shortage of doses was the primary reason why the drive at all CMC centres had to be suspended for a day,” the official said.

The vaccination at all civic body-run centres will resume on Friday. “With the available stock, we will be able to vaccinate a substantial number of people on Friday and Saturday. Sunday is a holiday. More vaccines are expected and vaccination will not suffer on Monday, too,” said another CMC official.

An official of the state e-governance mission that manages the chatbot said all people whose appointments were cancelled on Thursday would receive WhatsApp messages about their new slots. “The time slots are the same. The date has been moved to July 5.”