The latest Sero-survey report released by the Brihanmumbai Municipal Corporation (BMC) showed that 99.93 per cent of the healthcare and frontline workers in Mumbai had high antibodies. This is the sixth serosurvey done in the pandemic and the next will be done in another six months. Civic officials said antibodies were found in vaccinated employees which shows that vaccination has played a major role.
This was the first survey to quantify antibody levels. Out of the 3,099, antibodies have been found in 3,097 employees. From the Primary health setup, 726 samples were collected across 24 wards. 632 samples were collected from Doctors, Nurses, and Class IV workers working at the 15 peripheral and 2 special hospitals. 776 samples were collected from BEST from 25 Depots and 779 samples were collected from Solid Waste Management workers from all wards.
Suresh Kakani, Additional Municipal Commissioner said that the antibody was shown high in those participants who had taken booster or precautions dose. “The serosurvey reports are more promising as it has revealed that vaccination helps in developing higher antibody level.
“This shows that the third dose helps to provide further protection against the Covid-19. So, it is essential that the eligible population who have taken both doses, also get the due third dosage. However, in the next six months, there will be another survey of these individuals measuring antibody levels. After which we will come to know how long antibodies last. This is probably the first such survey in India,” he said.
Nearly, 99.35 per cent of the participants had taken Covid-19 vaccines of which 96.7 per cent had taken Covishield and 3.3 per cent had taken Covaxin. Also, 36.5 per cent of participants were inoculated with the third jab.
Unlike the previous serosurveys, for the first time, the sixth serosurvey will be conducted over nine months to find out if antibodies produced against Covid-19 are waning off.
The mean age of the participants was 43 years. Also, 58.10 per cent and 41.90 per cent of the participants were male and female respectively.
Dr Mala Kaneria, Consultant Infectious diseases, Jaslok Hospital and Research Centre said the third wave, driven by the extremely transmissible Omicron has affected a large proportion of the population. This wave was particularly notable for infection in a large number of healthcare workers, leading to disruptions in medical services and many
cases of reinfections were observed. The majority of the population had already been infected by Delta and its variants.
“Besides, practically the entire population is vaccinated and many, including health care workers, have received their precautionary dose as well. Consequently, many have acquired hybrid immunity (natural infection plus vaccine-induced immunity). Hence, the forthcoming serosurvey of HCWs is likely to show high seropositivity amongst HCWs,” she said.
Meanwhile, the fifth serosurvey conducted by the Brihanmumbai Municipal Corporation (BMC) in Mumbai in August 2021 showed that around 86.64 per cent of the 8,674 people surveyed had developed antibodies against Covid-19. While, the fourth serosurvey, which was conducted among the pediatric population, revealed that about 50 per cent had developed antibodies against Covid-19. The third serosurvey, which was conducted between February and March and covered 10,197 people, revealed that 36.3 per cent of the population had antibodies against Covid-19.
