Peerless Hospital had conducted the study on 294 patients with moderate to severe infection. The study found that of the 294 patients, 201, which is 68.4%, were unvaccinated while 15 had received Covaxin and 78 had got the Covishield jab.
Of the 93 patients who contracted the infection post-vaccination, 73 had taken the first dose while only 20 had taken both the doses of either of the vaccine. The in-hospital mortality rate among 294 patient was 13.4% when 40 patients died during treatment. Among the deaths, 26 were completely unvaccinated while 11 of them had got only the single dose. Only three had received both the doses — two of them Covishield and one of them Covaxin.
“Even among the three deaths who were fully vaccinated, they had contracted the disease within 14 days of the second jab. And patients who died post vaccination had severe co-morbid conditions like diabetes, cardiovascular diseases and malignancy. We found no significant difference in the effectiveness of the two vaccines,” said Peerless hospital clinical research and academic director Subhrojyoti Bhowmick, co-author of the study.
Doctors said that the human body takes about two weeks from the second dose to develop optimum immunity.
Published by a team comprising doctors Abhraneel Parames Guha, Aritra Chakrabarti, Subhrojyoti Bhowmick, Saibal Das, Rahul Khandelwal, Aditya Singh, Ajoy Krishna Sarkar, Anupam Das, Krishnangshu Ray and Sujit KarPurkayastha, the study was conducted between April and June.
This perhaps is the first time such a data on Covid-19 infection on post-vaccination has been published in the eastern India. The state government, too, has taken up such a project to study post-vaccination infection trends. “Available data shows that home-grown Covaxin has good efficacy. Now since most hospitals are taking vaccination history on Covid-19 patients during the second wave, they should also come out with their findings,” said immunologist Dipyaman Ganguly, a scientist at the Indian Institute of Chemical Biology, Kolkata.
“CMRI is collecting data to analyse exactly how many people got infected post vaccination, treatment outcome and mortality,” said CMRI pulmonology director CMRI Raja Dhar. “Though the number is less, we are still finding some patients with severe Covid infection even after two doses,” said Sauren Panja, medicine and critical care head at RTIICS.