COVID-19: Is the ICMR Antibody Kit Really as Accurate as It Claims?
The Indian Council of Medical Research (ICMR) recently made a welcome announcement: that it had built a testing kit to detect antibodies against the novel coronavirus in human blood samples. The kit, the agency said in its press release, was 100% specific and 98% sensitive.
A 100% specificity means that the test will never confuse other antibodies for those specific to the novel coronavirus. A sensitivity of 98% means when the kit checks a hundred blood samples containing the antibodies, it will detect the virus 98% of the time.
These are impressive claims. Few antibody tests anywhere in the world today boast of such accuracy. For example, the Elecsys antibody kit built by Roche, a global leader in medical diagnostics, claims 99.8% specificity and 100% sensitivity. ICMR’s kit seems to trump Roche’s on the first count. Such high accuracy should mean that the agency’s kit is perfect to estimate the true prevalence of COVID-19 in the country – a crucial question at this juncture. Because so many people with COVID-19 show no symptoms, it’s very hard to say how many Indians have been infected thus far.
An accurate antibody kit can solve this problem because the presence of antibodies specific to the novel coronavirus in a person’s blood would indicate that they’ve been exposed to the virus in the past.
ICMR plus various state governments have been planning surveys to estimate the percentage of Indians exposed to COVID-19 for a while now. These surveys are known as seroprevalence, or ...
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