Covid infections growing milder, occasional surges expected but don't worry: experts

New Delhi: Covid is growing milder with time but an occasional surge in cases is expected because the virus that causes it is now endemic and constantly evolving, say scientists while assuring that there is no cause for concern.

Addressing worries over the rising incidence of the disease in various parts of the country, the experts noted that it appears to be a result of waning immunity combined with seasonal factors such as temperature extremes, which tend to keep us in air-conditioned spaces. They also stressed the need for caution, particularly in vulnerable sections of the population.

"With every passing year, Covid-19 is causing milder infections. It is (now) just another respiratory illness and less dangerous than flu. We can forget Covid-19 as a special case. It is not a cause of concern," global health expert Dr Chandrakant Lahariya told PTI.

"All the subvariants are similar, having a lower virulence but high infectivity. While highly susceptible people can still get severe disease, the vast majority don't, especially those who have had prior infections or vaccines," added Anurag Agarwal, dean of biosciences and health research, Trivedi school of biosciences at Ashoka University, Haryana.

The World Health Organization declared an end to Covid-19 as a 'public health emergency' two years ago in May 2023. Health experts characterise the disease as 'seasonal', 'endemic', here to stay, or 'restricted to a certain region'.

Active cases in the country crossed 5,300 as of June 6, with nearly 500 added in the past 24 hours. Of these, over 4,700 have recovered. The death toll is 55 in the current surge which started January this year, primarily among individuals with pre-existing illnesses, according to the Union Health ministry.

"People with pre-existing illnesses and those older than 65 should follow standard precautions, as they would against any other respiratory infection -- not just for Covid-19," explained Lahariya, a consultant physician and former staff member of WHO.

Kerala is the most affected with over 1,600 cases, followed by Gujarat, West Bengal, Delhi and Maharashtra, ministry data shows.

The case surge in India is part of a wider wave impacting parts of Southeast Asia, including Singapore, Malaysia, Thailand and Hong Kong, which have been seeing a rise in infections over the past months.

Wastewater surveillance by the Council of Scientific and Industrial Research-National Chemical Laboratory (NCL) has detected presence of SARS-CoV-2 -- which causes Covid-19 -- in samples from 10 sewage treatment plants in Pune, the Times of India reported.

Patterns are similar to those seen in the weeks preceding earlier surges, NCL scientists were quoted as saying.

Genome sequencing of samples from India’s west and south have shown links to the subvariants of Omicron -- LF.7, XFG, JN.1 and NB.1.8.1. The cases are not severe and there is no need to worry, Director General of Indian Council of Medical Research (ICMR) Rajiv Behl said earlier this week.

LF.7 and NB.1.8.1. have been classified as 'variants under monitoring' (VUM) by the WHO to alert public health authorities that a variant of SARS-CoV-2 requires prioritised attention and monitoring. JN.1 has been circulating in India since November 2023.

The current situation, Behl stressed, is being monitored.

Immunologist Satyajit Rath explained that the subvariants driving up case numbers indicate that they are probably better at binding themselves to human cells, despite pre-existing antibodies created in response to a prior infection or vaccination -- or 'infectivity'.

“However, the important issue here is not their infectivity, but their tendency to cause severe disease, or 'virulence'," Rath, former scientist at New Delhi’s National Institute of Immunology, told PTI.

"Since selection pressure among the virus strains depends on infectivity and transmissibility -- and not on virulence -- there is no reason to expect a steady increase in the virulence of the emerging virus strains, which, in fact, has not at all been seen either," he added.

Moreover, given that the Covid-19-causing virus is now endemic and constantly 'mutating' or evolving, ups and downs in infections in the population are expected, the health experts said.

"People need not worry themselves until they are informed of a new 'variant of concern'. VUM is not relevant to the public, but only to public health authorities," Agarwal said.

Lahariya advised the public to gather information from reliable sources and not to forward unverified messages, while Rath suggested that citizens keep a watch for the virulence of newly emerging strains.

The experts also stressed on the role of authorities.

"National and state governments in India should keep a watch on cases, monitor the trends in new cases and share data widely. The linkage between infections and clinical outcomes should be explored to understand the clinical features of the variants in circulation," Lahariya said.

Rath drew attention to systemic issues that remain regarding preparedness of public health systems and availability of healthcare facilities across sections of the society should a virulent variant emerge.

"The catch is, how efficiently, systematically and rigorously are our public health systems tracking virus strains, their infectivity and their virulence, not only for SARS-CoV-2 but for any other infection?" he asked.

"Are we making next generation Covid vaccines at all? Are we making them available widely and affordably? Are we even carefully tracking evidence to see how well or poorly the current vaccine-induced immunity functions against emerging strains?" he added.

The poor and vulnerable would need special protection "but are masks being made widely and freely available? “And if not, we are throwing poor communities onto their own resources even for taking such simple precautions, and that is a systemic problem," Rath said.