THIRUVANANTHAPURAM: As Covid-19 cases flare up in the state, the health department is examining whether the recovered patients have the chances of reinfection. Though the department says that it is yet to come across such cases except for some suspicious ones, the possibility can’t be ruled out as it is not yet clear how long the antibodies provide protection to a recovered person.
There is also a demand to spearhead a study by roping in scientific institutions like Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST) and Rajiv Gandhi Centre for Biotechnology (RGCB) to examine whether the SARS-CoV-2 could strike again like other common human coronaviruses such as the common cold.
“Some studies have been done at the international level like the one by King’s College London which states that antibody responses to SARS-CoV-2 can peak three weeks after the onset of symptoms but begin to decline after as little as two or three months. If that’s the case, then a study on individuals who have been previously infected with SARS-CoV-2 in the state and whether they become reinfected should be examined,” said an epidemiologist of a government medical college.
At the same time, Chennai-based National Institute of Epidemiology’s director, Dr Manoj V Murhekar, told TNIE that there is very less chance that a recovered persons would get reinfected. Corroborating the same, Sreekumar E, chief scientific officer of RGCB, said sometimes it’s the RNA positivity during the recovery period that gets projected as reinfection. According to him, the positivity of viral RNA might be from the dead virus without active viral replications.
Meanwhile, A Sukumaran, former state epidemiologist, said though getting reinfected is very unlikely, there are a few reports of test positivity after one gets recovered. “The reasons for the same need to be verified by researchers,” he said.
According to Dr Anup Warrier, head of infectious diseases and infection control, Aster DM Healthcare, there has been no incident of reinfection in the state, but other states and GCC countries have reported such cases.
Earlier, in a study carried out by the COCOREC (Collaborative study COvid RECurrences) group and the findings published in the Journal of Infection, it has been stated that patients could experience re-activation or might be reinfected. It also points out that the potential long-term effects of drugs or diseases could hamper the immune response.
The study further recommends studies including genomic comparisons of viral strains involved in both episodes, determination of RNA infectivity by viral culture and others for understanding Covid-19 recurrences.