New Delhi: The Health Ministry on Wednesday shared findings of the fourth round of the national serosurvey conducted by the Indian Council of Medical Research (ICMR) across 70 districts of the country.
At least two-third of the population surveyed in 11 states were found to have developed coronavirus antibodies, according to the findings of a serosurvey done between June 14 and July 6.
Madhya Pradesh leads the chart with 79 per cent seroprevalence while Kerala is at the bottom with 44.4 per cent.
Seroprevalence or seropositivity was found to be 58 per cent in Maharashtra, 76.2 per cent in Rajasthan, 75.9 per cent in Bihar.
It was 75.3 per cent in Gujarat, 71.0 per cent in Uttar Pradesh, 69.8 per cent in Karnataka, 69.2 in Tamil Nadu, 68.1 per cent in Odisha, 66.5 in Punjab, 63.1 in Telangana, 50.3 in Assam and 60.9 in West Bengal.
What does low seropositivity imply
Seropositivity signifies the presence of antibodies in the blood serum.
“A seroprevalance of 44.4% can be interpreted in two ways. One, it implies that 65.6% of Kerala's population is still not infected by SARS CoV 2. Two, it makes our population more vulnerable to the third Covid-19 wave,” Dr Shahir Sha, Superintendent at Taluk Head Quarters Hospital, Punalur told Onmanorama.
“A serum study would detect antibodies from a natural infection and vaccine. The antibodies generated from a vaccine are more in number and they last longer in the body,” he added.
Since Kerala's vaccine drive is proportionately higher than other states, one can conclude that its population did not develop the antibodies through natural infection.
The fourth serosurvey is the first survey conducted after the rolling out of vaccination.
These findings imply that with limited herd immunity, Kerala should step up its vaccination drive as a majority of its population is still susceptible to the infection.
Centre advises states to take up survey
The Centre has advised all states and Union territories to conduct seroprevalence surveys in consultation with the ICMR to generate district-level data on seroprevalence which is essential in formulating localised public health response measures.
This was stated in a letter written by Union Health Secretary Rajesh Bhushan to additional chief secretaries/principal secretaries/secretaries (Health) of all states/UTs, a statement by the Union health ministry said.
Referring to the findings of the fourth round of the national seroprevalence survey done by ICMR, the ministry has advised states/UTs to conduct the seroprevalence studies in their own regions in consultation with the ICMR, so that such studies follow a standardised protocol, and the findings can then be utilised by the respective state and UT to guide objective, transparent and evidence-based public health response to COVID-19.
"The national serosurvey by ICMR was designed to capture the extent of the spread of Covid infection at the national level. Therefore, the national serosurvey results do not reflect the heterogeneity of seroprevalence between districts and even between states," the statement said.
(With PTI inputs.)