Coronavirus: What is the possibility of reinfection in COVID-19 patients? Here's what ICMR study has found

The scientific discussion around whether a person who has been infected with SARs-COV-2 virus, develops permanent immunity or is prone to reinfection has been going on for quite some time now. Scientists and medical professionals are working tirelessly to find answers for the same and believe that it will be a great milestone in the battle against COVID-19. A recent study has looked into the matter and has found some of the most plausible cases of COVID reinfection in India.

The study, conducted by a team of scientists from the Indian Council of Medical Research (ICMR), examined the cases of 1,300 individuals who had tested positive for the virus twice. Researchers found that out of the 1300 cases, 58 or 4.5% cases could be termed as possible reinfections. That said, of the 58 cases, the two positive results had come at least 102 days apart, with instances of negative test results in between.

“A working epidemiological case definition of SARS CoV-2 reinfection is important to strengthen surveillance. The present investigation contributes to this goal and records reinfection in 4.5% of SARS CoV-2 infected individuals in India," the study explained.

According to the study, which has now been accepted to be published in the Epidemiology and Infection journal, reinfection is when an individual tests positive for the virus on two separate occasions at an interval of 102 days with a negative test result in between.

As per the study, cases of reinfection can only be confirmed with the help of genome analysis of the virus sample. Given that the virus continues to mutate, scientists believe that the genome sequences of the two samples would show some differences.

However, the study conducted by ICMR did not resort to genome sequencing due to a lack of genome samples data. Dr Samiran Panda, head, epidemiology and communicable diseases, ICMR, one of the authors of the study said, “The reinfection cases were earlier confirmed by only genome sequencing for which we need specific infrastructure, which may not be available everywhere. With the new definition, we can easily tab reinfection cases in India."

The scientists involved in the study instead relied on evaluating those patients who had reported getting reinfected with the virus for the second time after an interval of more than 102 days.

For a more reliable finding, the scientists took only those cases of reinfection into consideration in which individuals had tested positive for COVID twice during the period of 102 days, but had also tested negative once in between.

Due to the absence of a genome analysis, COVID reinfection cases in this study cannot be considered conclusive. However, the study concluded that permanent immunity among people who have got infected with the virus cannot be assumed. In addition to it, experts have advised people to continue maintaining social distance and taking all public health measures. Use of masks post-recovery is highly recommended.