Recently, some Columbia researchers found out that people have frequently got reinfected with the same coronavirus, sometimes in the same year. A report published by Technology Review said, "Over a year and a half, a dozen of the volunteers tested positive two or three times for the same virus, in one case with just four weeks between positive results."

In the case of infections like measles or chicken pox, a patient attains immunity for life once the infection has set in. However, coronavirus could well fall into the category of TB and malaria.

Speaking to a Telugu daily, the famous orthopedic surgeon Dr. Dasaradha Rami Reddy, who works for Yashodha Hospital in Hyderabad, said that this is a cause for concern. Nobody can know how long one can stay immune to the virus even after Covid-19, which is a coronavirus, attacks and goes away.

"This has to be seen as a warning," the doctor cautions in the interview.