NEW DELHI: The popular assumption that getting Covid-19 once gives a person lifetime immunity against the virus does not seem to hold true. Doctors in major metro cities such as Mumbai, Delhi, Bengaluru, Kolkata and Kochi are seeing reinfections, some within a span of just two to three months.
Health experts feel that the virus can infect people multiple times, regardless of the vaccination or boosters, thus increasing the overall risk of complications and adverse health outcomes.
A recent US study has said that the previous Covid infection makes the next infection worse. The study in Research Square, which was published as a preprint and yet to be peer-reviewed, said that reinfection contributes to an additional risk of death and adverse impact on the pulmonary and several extrapulmonary organ systems.
It also said that compared to those with the first infection, people with reinfection had an elevated risk of all cause-mortality and increased risk of hospitalisation.
Prof K Srinath Reddy, president of Public Health Foundation of India (PHFI), said it is clear that Omicron and its sub-variants have greater propensity for immune escape.
Added Dr Rajeev Jayadevan, co-chairman National Indian Medical Association (IMA) Covid-19 task force, Omicron appears to have evolved not only to spread faster but also to evade immunity against itself.
“This means that we can expect more frequent reinfections. Doctors are observing that anywhere from 15 to 80 percent of Covid-19 patients whom they treat now are indeed reinfections. This will become the norm in the future, and it is important to reduce the impact of these infections because we do not know the long-term outcome of repeated bouts of the virus,” the former IMA past president said.
He conducted a patient outcome study in April, the first in India, which showed that some people got reinfected not thrice but five times.
Experts in the first year of the pandemic had said that after vaccination or natural infection, one would become immune for a lifetime. But in 2022, they have been proved wrong.
As Covid-19 cases surge in the country, reinfections will become "normal," experts said.
Kerala-based Jayadevan said doctors have shared with him that many patients, who had reinfection, saw severe bouts too when they got infected again.
Dr Sanjith Saseedharan, consultant and head of critical care, SL Raheja Hospital, Mahim, Mumbai, said they have seen almost 30 to 40 per cent cases of reinfections. “Some reinfections have occurred in the span of two to three months, after the primary infection.”
Senior director internal medicine, Medanta hospital, Gurugram, Dr Sushila Kataria, said they are seeing repeat infections, with many infected three times.
Dr Satyanarayana Mysore, head of department and consultant pulmonology, lung transplant, physician, Manipal Hospital, Bengaluru, in the fresh Covid surge a number of people have reported reinfections.
Till June 15, health authorities at Fortis Hospital, Anandapur, Kolkata, said, approximately 45 percent of patients were those who were reinfected.
The silver lining, however, in the Indian context so far is that these reinfections haven’t resulted in a spike in mortality or severity leading to long hospitalisation, despite western data pointing out that reinfections are generally a bit more severe than the primary infection.
The main reason for reinfection is not only masked fatigue but also reluctance to take the booster and increased mobility in addition to the virus being more transmissible than before.
“It is logical to state that reinfections can lead to the loss of social, economic, and mental well-being of people,” Saseedharan said.