Hyderabad: Half of Hyderabad's population has already been infected by COVID-19. Around 54 per cent of the city's population is estimated to have antibodies against COVID-19, according to a joint study conducted by CSIR- Centre of Cellular and Molecular Biology (CCMB), ICMR- National Institute of Nutrition (NIN), and Bharat Biotech seroprevalence survey in the city.
Around 9,000 samples were tested for antibodies against the virus across 30 wards of the city. Three hundred people were surveyed in each ward, all of them older than 10 years. Most of the wards reported as high as 70 per cent or as low as 30 per cent people had developed the antibodies against the novel coronavirus.
Women showed a marginally higher seropositivity rate (56%) than men (53%). Those above 70 years of age showed lower seropositivity (49%), perhaps because of limited mobility and extra care taken by older individuals during the pandemic. Unsurprisingly, households with COVID-positive cases showed the maximum seropositivity of 78 per cent. This was followed by those with known COVID-19 contacts outside their households (68%).
Dr. A. Laxmaiah, a scientist at NIN, observed that houses with large number of rooms and small households showed low prevalence of coronavirus infections.
"This multi-stage random sampling study of 9,000 people in the city showed that more than 75 per cent of the seropositive population did not know that they had contracted the coronavirus. This suggests seroconversion, that is antibodies have formed even with silent infections," said Dr. R Hemlatha, the director of NIN.
According to the study, individuals who had experienced prominent COVID-19 symptoms as well as those who were asymptomatic, both had equivalent seroprevalence of around 54 per cent. Around 18 per cent had been tested earlier and found positive for the coronavirus and around 90 per cent of them were found to be seropositive, suggesting that they had retained the antibody response.
Dr. Rakesh Mishra, the director of CCMB, said, "This study brings a comprehensive perspective of potential protective immune response against the coronavirus in the city's population. The data indicates that the population of Hyderabad might be slowly moving towards herd immunity, which will be certainly accelerated by the ongoing vaccination efforts."