Concerns on waning immunity as 5.5 lakh in Tamil Nadu miss Covaxin booster on due date

CHENNAI:  A total of 5,53,116 people in Tamil Nadu have missed taking their second dose of Covaxin within the stipulated time, according to data by the Directorate of Public Health (DPH). This raises the possibility of waning immunity due to the longer gap.

As per data gathered by the DPH from the COWIN portal and shared with Express, these beneficiaries had taken their first dose between January 16 and July 15.

Ideally, all of them should have taken their second dose by now, but as of August 26, they hadn’t. 

Unlike Covishield’s interval for the second dose (increased from 12 to 18 weeks), the time gap for Covaxin was not increased by ICMR, even though there were supply constraints initially.

ICMR head Dr Balram Bhargava in May had said immunity after the first dose of Covaxin was not as high and this means, the second dose must be taken after four weeks to ensure maximum efficacy.

While supply constraints of Covaxin have eased to some extent in Tamil Nadu, getting people to take their second dose has always been a challenge.

“We are exclusively using this vaccine only for those requiring the second dose. We have line data of those who missed it and those people would be intimated to come and get the vaccine,” said Health Secretary Dr J Radhakrishnan. 

He said supply constraints are not an issue now and the Public Health Department is holding special camps exclusively for second-dose beneficiaries. Tamil Nadu has so far received 42,88,860 doses of Covaxin and in that, 39,25,448 doses (92%) have been used. 

Director of Public Health Dr TS Selvavinayagam said at least now, people must use the opportunity to take the second dose.

“Only if you get two doses, you would get full benefits of the vaccine,” he said.

Infectious diseases specialist Dr Subramanian Swaminathan said for vaccines other than Covishield, there’s no data for longer-gap efficacy.

“Having said that, the idea is to minimize errors. So it is very important for people to take the second dose at right time,” he said. 

Vaccination drive for students of 112 colleges

CHENNAI: With colleges in the State all set to reopen, the Chennai Corporation and the health department have decided to inoculate students aged above 18 from 112 colleges in the city, against Covid-19 from September 1.

Addressing reporters during the inauguration of a vaccination camp for students at the Nandanam Arts College here, Health Minister Ma Subramanian said by the second week of September, 100% of college students aged above 18 would be administered the vaccine.

“In Chennai, 90 per cent of the teachers have already received the vaccine,” the Minister said. “As much as 84.3 per cent of the non-teaching staff have  also already been vaccinated against Covid.”