Experts yet to diagnose causes for relapse

With similar instances of relapse occurring in Karnataka and Gujarat, many are curious about the possible causes for relapse. According to medical experts, one possible reason could be alternative strains of the disease attacking the immune system of the patient.

“One possibility for relapse could be due to the person contracting a different strain of the virus. Should a patient be re-infected, the acquired immunity through the antibodies might not be effective in holding off the new strain they have contracted,” said Dr Sivakumar, Head of Department, General Medicine, Villupuram Medical College.

According to a report published by the WHO, there is no evidence to suggest that those who have recovered from COVID-19 and have antibodies are immune to a second infection. A clinical study published by the Elsevier Public Health Emergency Collection last month noted that the use of “immunosuppressive factors such as drugs or pathological conditions could contribute to impair viral clearance and favour SARS-CoV-2 reactivation.”

Calling for more follow-up studies on the same, Dr Shantha, retired director of Madras Medical College, said that factors like viral shedding and short-lived immunity could cause a relapse and need to be studied closely.

“We are continuously learning from this disease, and as of now, we cannot say why a relapse could occur. While everyone talks about maintaining immunity levels, there is a chance that the viral load might be high. The chance of relapse depends on exposure levels to the virus and immunity levels in the patient,” said Dr Asokan, dean, Coimbatore Medical College Hospital.