Bengaluru:

Fortis Hospital has reported Bengaluru’s first case of Covid reinfection – a 27-year-old woman with no history of comorbidities who had first tested positive in July and was discharged upon full recovery from a mild form of the disease – the hospital’s official statement said, adding that tests conducted on the patient show she did not develop any immunity towards the novel coronavirus.

“This is possibly the first reported case of Covid reinfection in Bangalore,” Dr Pratik Patil, a Infectious Diseases Consultant at Fortis Hospital’s Bannerghatta Road facility said, explaining how the woman developed the disease a second time within a month’s time.

“Normally, in case of infection, the Covid Immunoglobulin G antibody test comes positive after 2-3 weeks of infection (showing that the patient has developed Covid-fighting cells). However, in this patient, the antibody test has come out negative, which means she did not develop immunity after first infection. The other possibility is that the antibodies disappeared within a month, leaving her susceptible for reinfection,” Dr Patil said, adding that her symptoms after reinfection are mild.

“Reinfection cases mean that the antibodies may not be produced by every individual, or, if they do develop, they may not last long enough, therefore allowing the virus to enter the body and cause the disease again,” he said.

The finding raises worrying questions about controlling and ending the COVID-19 pandemic as cases continue to rise in India – Asia’s worst-hit country – which recorded almost 90,000 daily cases taking its tally past the 41-lakh mark today.

It also raises questions about the duration for which a vaccine would remain effective.

However, scientists in India and elsewhere have said re-infections are rare and there is no reason for alarm just yet. They added that more studies are needed for a reliable inference, calming fears that herd immunity may not be enough to curb the COVID-19 pandemic.

Cases of re-infection have also been reported from Telangana and Maharashtra in India, and other countries, including Hong Kong, US, Netherlands and Belgium.