NIV develops test to detect antibodies
Indigenous ELISA test will be used to screen 30,000 samples from 75 COVID-19 hotspot districts
- The National Institute of Virology (NIV), Pune, has developed an immunological assay — enzyme-linked immunosorbent assay (ELISA) — to detect antibodies that the body develops in response to infection by the SARS-CoV-2 novel coronavirus.
- The test will detect antibodies in blood samples.
- ELISA is routinely used for detecting HIV infection.
- This is the first time India has developed an indigenous ELISA test for coronavirus.
- While ELISA tests for coronavirus are already available in other countries, procuring them in large numbers may be a challenge, particularly during a pandemic.
- In contrast, availability will be a non-issue when a locally developed test is manufactured in India.
- The company that has been licensed to manufacture the ELISA test kit will have about a month to make the tests available as collection of 30,000 blood samples taken randomly from the general population in the 75 hotspot districts.
- The ELISA test developed by NIV gains significance as the rapid antibody tests imported from China were found to be unreliable and hence the States were instructed not to use them for detecting previous novel coronavirus infection.
- India has thus far maintained that there is no community transmission despite there being over 63,500 cases so far from across the country.
- Since the ELISA test is based on detection of antibodies, it can only help in knowing if the person has been previously infected by coronavirus.
- Since it detects antibodies, even people who have remained symptom-free (asymptomatic) during the entire course of the infection will test positive.
- While the RT-PCR (reverse transcription polymerase chain reaction) test, which detects the RNA of the coronavirus, enables detection of current infection, it will not be useful if the testing is carried out days after the infection clears as the virus will no longer be present.
However, antibodies developed in response to the coronavirus infection will be present in the blood for a longer duration and hence the ELISA test can help detect past infection.