BENGALURU: Anecdotal data in Karnataka has shown that a majority of the Covid-19 cases in Karnataka are reinfections, mimicking the trend discovered in the UK by a recent study conducted by researchers from the Imperial College, London.
The study found that more than two-thirds of cases of the Omicron infections are people who have been reinfected with the virus.
“Yes, we have also observed similar trends in the country wherein two-thirds are reinfections amongst those who are vaccinated patients with immune escape, resulting in breakthrough infections. Hybrid immunity has helped in reducing the severity of symptoms and mild cases with shortened duration of illness has been observed,”said Dr Niranjan Patil, AVP & Scientific Business Head-Infectious Diseases, Microbiology & Molecular Biology-Head, & Biosafety Officer, Metropolis Healthcare Ltd.
Agreeing that he has seen many such patients, some of whom have been infected in all three waves, renowned pulmonologist and sleep medicine expert Dr Satyanarayana Mysore of Manipal Hospitals jokingly refers to them as “habitual offenders”.
He explains that theoretically, it is possibile to get infected with the Covid-19 virus multiple times.
“The T-cell memory, or the antibody generated, may help in reducing the severity of the disease, but unless Covid-Appropriate Behaviour is followed and masks are in the right place, there is every possibility of the person contracting the virus. It is less of innate immune dysfunction but more to do with the place and nature of work, diligence, adapting CABs which may be the predisposing factor,” he noted.
The Omicron variant can spread among the population at a rate three times faster than the Delta variant and the virus is different in its make-up. Dr Srivatsa Lokeshwaran, Consultant Interventional Pulmonology, Aster CMI Hospital, says that this could be the reason for reinfections in those who are already infected with a different variant and also in those who have waning immunity after vaccination.
“Since worldwide, Omicron is establishing itself as the dominant variant, it’s going to affect a large population which causes this overlap or feeling of overlap on previously infected cases,” he says, stressing on the need for precautionary doses for all.
Meanwhile, elaborating on the reduced risk of severity in illness in many of the reinfection cases, well-known epidemiologist and public health expert Dr Giridhara Babu says that in most instances, immunity acquired following primary infection with SARS-CoV-2 will protect against hospitalisation and death upon subsequent exposure to the virus.
“Based on the evidence, the risk of reinfection versus primary infection was lower during waves driven by the Beta and Delta variants and higher for Omicron. This could be possibly due to the decreased level of antibodies and diminished protection against infection. However, this gets modified with vaccination subsequent or prior to infection,” Dr Babu explained.
Dr. Subrata Das, Senior Consultant - Internal Medicine & Diabetology, Sakra World Hospital, said, “We are seeing many reinfecting cases in Covid. Most households in the last 2-4 weeks have had cold, cough, fever and throat pain. Many of the patients who are testing positive at this point, would have had covid sometime earlier maybe 2 to 6 months back. Though the symptoms are being observed at a milder state, we are witnessing reinfection at a faster pace. Maybe there is a chance of 10-15% of people getting reinfected.”