BENGALURU: The fourth national sero-survey conducted by the Indian Council for Medical Research (ICMR), has revealed that in some cities in Karnataka, the Covid-19 sero-prevalence is over 80 per cent among health care workers.
In the general population, the sero-prevalence in Bengaluru is 70 per cent, in Kalaburagi 67.3 per cent and in Chitradurga 64.8 per cent. Among health care workers, it is 86.1 per cent in Bengaluru, 89.5 per cent in Kalaburagi and 82.8 per cent in Chitradurga. These figures were communicated by Dr Balram Bhargava, director general, ICMR, in a letter to the state Additional Chief secretary, Health and Family Welfare, Jawaid Akhtar on July 23.
To determine the district-wise sero-prevalence, antibody tests were conducted. As per the findings, more than 80 per cent of the health care workers and more than 60 per cent of the general population have developed protection against Covid-19.
“Whether this is by natural immunity as a result of previous SARS-CoV-2 infection, or immunity derived from Covid-19 vaccination, we cannot say,” explained Dr Pradeep Banandur, member of the Covid-19 Technical Advisory Committee (TAC) and Additional Professor, Department of Epidemiology, National Institute of Mental Health and Neuro Sciences.
“Epidemiologically, we consider both Covid-19 infection and vaccination as the cause for high sero-prevalence rate, leading to protection amongst a significant section of the population. We have been able to give effective protection to our health workers. As for the general public, the high sero-prevalence might be why we are seeing fewer Covid-19 cases now,” Dr Banandur reasoned.
As per the ICMR sero-survey on those aged above six years, 313 samples were positive among 447 tested in Bengaluru Urban, 288 samples positive among 428 tested in Kalaburagi and 293 positive among 452 tested in Chitradurga, in the general population. As for health care workers, 93 samples were positive among 108 tested in Bengaluru Urban, 102 positive among 114 samples tested in Kalaburagi and 96 positive among 116 samples tested in Chitradurga.
Dr Banandur said this means the government can claim that the lockdown has been effective and that unlocking can be done while remaining guarded. “We can safely open colleges, but need to follow Covid-19 appropriate behaviour owing to emerging variants,” Dr Banandur added.