Government Medical College (GMC) Srinagar conducted a study in District Srinagar to estimate the seroprevalence of IgG antibodies against SARS-CoV-2 among the general population on October 17 and 18. Plainly put, seroprevalence is the level of a pathogen in a population as measured in blood serum.
A total of 2361 blood samples were analyzed for the presence of the antibodies against the virus using “Chemiluminescent Microparticle Immunoassay (CMIA)”, a high sensitivity and specificity for identification of IgG antibodies against the pestilence. The test provides information about past infection due to SARS-CoV-2, the coronavirus that causes Covid-19.
Nine hundred fifty-nine (959) samples were positive for the IgG against virus giving a seroprevalence of 40.6%.
The seroprevalence was significantly higher among females (459/1026=44.7%) as compared to males (500/1335=37.5%), it concluded.
As expected those with a history of Influenza-like illness (ILI)-symptoms in the previous three months, and those had come in contact with a known COVID-19 patient had higher seroprevalence as compared to their counterparts with no such history.
Also on expected lines, those living in the dense agglomerations such as at Khumaini Chowk, Bemina West and Eidgah were infected in large numbers as compared to other surveyed places.
A dominant theme driving government bodies is aimed to check for levels of ‘herd immunity’, or if around 60-80% of the population have encountered the infection.
The argument behind herd immunity is that this degree of exposure will protect those who are not immune to the disease.
For example, if 80% of a population is immune to a virus, four out of every five people who encounter someone with the disease won’t get sick and won’t spread the disease any further. IgG antibodies against the virus usually develop two weeks after the infection and should be perceived as diagnostic of COVID-19, the experts say. However, in the absence of knowledge about how long antibodies last and the extent to which they protect from fresh infections, reliance on herd immunity should not be pursued as part of the policy to be complacent. There is a need to be guarded until an affordable vaccine is available against it. The survey has underlined that the seroprevalence may further increase in the near future as “more and more individuals become infected and develop antibodies against the virus.” In other words, more people are likely to be exposed to the pathogen, and as such large population continues to be vulnerable and needs to take protective measures.