Recent research found that 57% of participants from slums and 16 % from non-slum areas are having COVID-19 antibodies. A serological survey was conducted of around 7,000 people in Mumbai.
The survey was jointly conducted by NITI-Ayog and TIFR. From the research, researchers intended to prove how common antibodies against the coronavirus are in the general population.
Random sampling was used in the survey to pick volunteers from Mumbai’s R-North, M-West, and F-North. Volunteers selected were of different age and gender.
Samples were collected from each volunteer at two different time points, to understand the pattern of spread in large sample size over a while. On 27 July, the results from the first round of antibody surveys were made public.
Researchers also found that women had more antibodies as compared to men. They further inferred that a huge portion of all infections is probably asymptomatic.
The higher dominancy of antibodies in slum areas could be due to the dense population and many people sharing common facilities like toilet, and water pumps.
The case fatality rate is around (5-6)%, however, the infection fatality rate is low i.e. below 0.1%, as per data and records from BMC on reported deaths.
This could also be a reflection of effective efforts to contain active cases and isolate symptomatic ones by the municipality, they said in the first report.
Better social distancing and access to good hygiene are ways to curb the spread of COVID-19, however, researchers suggested that these two ways can possibly explain the lower antibody prevalence in non-slum areas surveyed. They added that interventions from local municipality also contributed to the lower antibody prevalence in non-slum areas surveyed.
“These results will be valuable to learn more about herd immunity,” the report reads. “Although it is still unclear what level of prevalence leads to herd immunity, findings indicate that at least in slums, this could be attained sooner than later, if the immunity exists and persists in a significant proportion of the population.”