Mum doc tests +ve thrice, twice after vaccination

Mum doc tests +ve thrice, twice after vaccination

Malathy Iyer TNN

Mumbai:  27.07.2021

A 26-year-old Mulund-based doctor has tested positive for Covid-19 three times since June 2020, twice after she got fully-vaccinated earlier this year. “The reinfections are confusing,” said Dr Shrushti Halari, whose swab samples have been collected for genome sequencing as part of a study on breakthrough infections (occurring after a person is vaccinated).

While there are no clear answers for why the doctor got Covid thrice, doctors told TOI that the reasons could range from SARS2 variants to her immunity levels to an incorrect diagnostic report (though RT-PCR is the gold standard for Covid-19 testing, it has a sensitivity of around 70%-75%).

Reinfections among doctors have been reported across the world, with a couple of studies from within Mumbai hospitals as well. However, reinfections cannot be proved until swab samples from the two (or more) infections are compared using genetically sequencing.

On Monday, a BMC official said Halari’s latest samples were collected to check why she got infected despite vaccination. Studies — one by BMC and another by a private hospital — are underway to look at reasons for breakthrough infections in collaboration with the Foundation for Medical Research (FMR).

Dr Halari, who tested positive the first time on June 17, 2020, while working in BMC’s Covid centre in Mulund, was RT-PCR positive on two more occasions — May 29 and July 11. “I got mild symptoms all three times,” she said. The first time she got tested for Covid-19 last year was because a colleague tested positive. In July, her entire family, including her parents and 21-year-old brother, tested positive.

Regarding Dr Halari’s three positive reports, her treating doctor, Mehul Thakkar said, “It could a case of an incorrect RT-PCR report or that the second infection in May got reactivated in July”. Dr Thakkar had highlighted her case to BMC health officials, which led to swab samples being collected for the FMR-BMC study.

FMR director Dr Nerges Mistry said reinfections could occur due to several reasons, including a person’s immunity levels or autoimmune conditions. “One other reason could be emergence of a new variant of SARS-CoV-2 virus,” she said.