An identity check at the gate, a placebo injection in the vaccination room and a 30-minute wait in the observation room to note any adverse effect — these were three crucial steps of the dry run for Covid-19 vaccines conducted in three places of Bengal on Saturday.

Seventy-five front line workers volunteered as recipients of the placebo during the dry run conducted at an urban primary health centre of the Bidhannagar Municipal Corporation at Salt Lake’s Duttabad, at the Amdanga Rural Hospital in North 24-Parganas and another urban primary health centre of Madhyamgram municipality. There were 25 volunteers at each of the sites.

State health department officials said the dry run was a dress rehearsal for actual vaccination. Its objective was to identify any loopholes in the system — whether the vaccinators were able to inject the placebos properly, whether the identity was checked or whether the Co-Win app, where details of a beneficiary would be uploaded after the vaccine was administered, worked properly.

The dry run also helped to see if the cold chain was maintained well. “The dry run was completed without any glitch. It was successful,” said Ajay Chakraborty, the director of health services of the state government.

The dry run is a mock vaccination without giving the actual vaccine, said another senior health department official.

The official explained the steps the volunteers, acting as potential Covid-19 vaccine recipients, underwent on Saturday. “The volunteers had to bring identity cards that were also their address proof. They were allowed into the centre only if they were among the ones that were asked to come on Saturday,” said the official.

This was necessary because Covid-19 vaccine will be given only to those people who are pre-registered with the Covid-19 Vaccine Intelligence Network (Co-Win) app that has been created for the vaccination. It is also mentioned in the Covid-19 Vaccines Operational Guidelines, issued by the Union ministry of health that was last updated on December 28. There will not be any on-the-spot registration.

Sources in the health department said vaccination teams would have the list of 100 people who would be given the vaccine in that session.

A volunteer first entered the waiting room where a basic health check was done and his/her identity was matched with the list available with the vaccination team.

The person was then sent to the vaccination room where the vaccinator administered the placebo.

An assistant entered the details of the person in the Co-Win app once the placebo was administered. The volunteer was next taken to the observation room where the person had to spend 30 minutes. “The observation time of 30 minutes is kept to see if there is any adverse reaction after taking the vaccine. In actual vaccination, the person would be told the date when the second dose has to be taken and where to contact if there is any adverse reaction,” said the official.

There will be control rooms in each district where the recipients can call, he added.

The 25 volunteers did not come together, but in gaps to ensure that they did not crowd the centre. This was done to ensure physical distancing.