ICMR’s 4th national serosurvey ‘will tell us about antibodies in vaccinated people’ as well: All you need to know
- The fourth survey will be the first one to be conducted after vaccination has been rolled out for the general population.
Indian Council of Medical Research (ICMR) is all slated to conduct the fourth national serosurvey in the country this month, Dr VK Paul, Member of Niti Ayog (health) told reporters during a press briefing on Friday.
A serosurvey is useful in detecting the presence of Covid-19 antibodies in the human body; the presence of antibodies signifies the person has been exposed to the virus. Sero-surveys test the liquid part of blood or ‘serum’ and not fluid present in the nose, throat, and mouth. Sero-surveys provide us with a broad picture of the spread of the infection.
What we know about the fourth national serosurvey so far
This will be the fourth serosurvey conducted by the ICMR in the country, after the third nationwide serosurvey conducted between December 17, 2020, and January 8, 2021. It will be conducted in 70 districts across the country and will also include children aged six years and above. Paul stressed the need for state-wide serosurveys to “protect our geographies” from threats of the pandemic. He urged states to conduct serosurveys at Covid-19 hotspots and infection spots at district and state levels.
The fourth survey will be the first one to be conducted after vaccination has been rolled out for the general population. Centre for Cellular and Molecular Biology (CCBM) advisor Dr Rakesh Mishra told news agency ANI that this new survey will tell us more about the presence of antibodies in vaccinated adults.
What have we learnt from serosurveys so far?
As per the last survey, at least one in five Indian above the age of 18 years had been exposed to coronavirus by January 8. Experts opined that the findings were indicative of a large proportion of the country – nearly 80% – remaining susceptible to the virus. The last serosurvey also established that seroprevalence in children between the ages of 10 and 17 was at 25.3%, whereas in healthcare workers, it stood at 25.7%.
A serosurvey also gives nuanced data along the gender and occupational lines. The last survey found that more women (22.7%) had Covid-antibodies compared to men (20.3%). It also established that out of the 7,171 health care workers from taluk hospitals, community health centres, primary health centres, etc, from each district covered in the serosurvey, doctors and nurses were affected the most with a seroprevalence of 26.6%, followed by paramedical staff (25.4%), field staff (25.3%), and administrative staff (24.9%).
All three serosurveys conducted till date have been carried out in 700 villages, 70 districts from 21 states in the country. In the first one, adults were surveyed during the period of the second half of May to early June, and seropositivity of 0.73% was reported. The second survey was carried out during August and September and it found seropositivity of 6.6% amongst all those aged 10 years and above.
Serosurveys, however, do not tell us if the population tested is protected from any further infections. It detects all antibodies present in the body and not all antibodies are protective in nature. Thus, vaccination in combination with Covid-appropriate behaviour remains the key to fighting Covid-19.