Indian Council of Medical Research (ICMR) on Thursday said that 5 lakh antibody test kits of two kinds have arrived from China. The kits from Chinese companies namely Guangzhou Wondfo and Zhuhai Livzon are 70 per cent more sensitive in detecting the virus, ICMR also said. They are likely to have a specificity of over 80 per cent. The ICMR had recommended the use of rapid antibody testing for coronavirus in high containment zones on April 2. Both are serological kits and can be differentiated on the basis of bands - IgM and IgG.
There are two kinds of antibodies in a human body namely immunoglobulin M (IgM) and immunoglobulin G (IgG). While the IgM antibody arrives within five to seven days of getting the infection, IgG arrives when the person has recovered. These antibodies are meant to fight the virus. However, only about 80 per cent people may even show the antibodies, ICMR also said.
The rapid antibody tests are however not meant for early diagnosis, ICMR said. The tests generally take a longer time to produce an antibody response. The RT-PCR test is the ultimate decider, it said. India has so far relied on the definitive RT-PCR, or reverse transcription polymerase chain reaction, tests.
India is under a nationwide lockdown to fight against the coronavirus pandemic. So far, the government has conducted 2,90,401 tests. On Wednesday 30,043 tests were conducted, highest in a day. According to the latest data, India recorded 826 new coronavirus cases and 28 deaths in 24 hours. The ministry added that there are a total of 12,759 coronavirus cases as of date with death toll at 420, while 489 people have recovered so far.