Dr. Rakesh Mishra, the CCMB (Centre for Cellular and Molecular Biology) advisor, has stressed the importance of a nationwide serosurvey and mentioned that the current Coronavirus variant, the Delta variant, is likely to change face in the next two months.
The Indian Council of Medical Research (ICMR) is ready to begin the fourth national-level serosurvey to assess the spread of COVID-19 in all states and Union Territories. Dr. Rakesh Mishra, the Centre for Cellular and Molecular Biology (CCMB) Advisor, has stressed that conducting a nationwide serosurvey is crucial as the Delta variant (B16172) COVID-19 will likely mutate considerably in the next two months.
India has conducted three serosurveys during this pandemic so far. Soon, the 4th serosurvey will be performed, and the reduction in the daily number of new cases makes it crucial. According to Mr. Niti Aayog, the preparations for this national serosurvey have been underway for a while and are now complete, and the work for the serosurvey will begin shortly.
What is a serosurvey?
Serosurvey or serologic studies examine the number of people in a population infected with COVID-19 and the recovery from the same. It is done to quantify the prevalence of any virus in a particular area. A serosurvey involves testing a group of individuals’ blood serum for the presence of antibodies against that infection.
In the past, multiple countries have used serosurveys for several diseases and quite effectively at that as well. This type of survey has been utilised to check the effectiveness of vaccination programs for other conditions such as measles, rubella, polio, etc.
How is a serosurvey conducted?
To conduct a serosurvey, blood samples are taken from a group of randomly selected people from a preset population to study the scale of undetected infections. The collected blood samples are tested for the presence of IgG (Immunoglobulin G) antibodies that determine a past infection due to the virus. A serological survey is primarily structured around IgG Enzyme-Linked Immunosorbent Assay or ELISA test. The test has high sensitivity and specificity and is thus approved by ICMR.
Even though IgM antibodies start getting positive after a week of contracting the virus, they indicate active COVID-19 infection and disappear soon. On the other hand, IgG antibody develops after the infection has progressed beyond the two weeks mark and remains in the body for a sustained and more extended period and thus, can be detected.
How deadly can the new variant be?
No one can altogether gather the extent of devastation that a new variant of covid-19 can cause. The emergence of the delta variant brought a ravaging second wave into the country, responsible for numerous deaths and more than 400000 new cases per day at a point in time. If the past is any indication, it can get very tough to handle another mutation in the novel coronavirus.