New Delhi: In the three years in which COVID-19 plagued the world, there have been several sub-variants of the novel coronavirus, of which Delta proved the most dangerous.
Since last January, there have only been sub-lineages of these variants, with the current surge attributed to XBB.1.16, a sub-lineage of the Omicron variant. Yet the approach towards managing COVID has remained the same.
Is it time now to introduce a fresh interpretation of COVID data? Yes, say epidemiologists. Among them is Dr Chandrakant Lahariya. “The new infection has limited intensity, so the number of new daily cases or the positivity rate are not good parameters,” said Lahariya. “When testing was taking place on a mass scale, the positivity rate had some meaning. Now the focus should be on hospitalisation rate or fatalities.”
Lahariya added, “The approach needs to be ECG now – epidemiological, clinical and genomic surveillance. All three must be interpreted together to arrive at a conclusion, not just the number of cases.”
Epidemiologists feel that new variants will continue to emerge and that there is a clear dissociation between infection and disease since the emergence of the Omicron variant. “With COVD as an endemic disease, it is crucial to maintain proactive surveillance until we detect trends in changing severity. Continued monitoring and analysis of data can help guide the next course of action,” said Dr Giridhar R Babu, head, life course epidemiology, Public Health Foundation of India.
Should there be another round of inoculation and should the existing vaccines be tweaked? Experts said both must be considered based on evidence. Abroad, manufacturers such as Moderna and Pfizer came up with bivalent vaccines last year. Bivalent vaccines include a component of the original virus strain and a component of the Omicron variant to provide better protection against Covid caused by the Omicron variant.
While Lahariya said that by the time a new vaccine emerged, there might well be another mutant, Dr Lalit Kant, former scientist, ICMR, said research should establish how effective bivalent vaccines were because the virus constantly mutates. He added, “Also, more studies should be done to see if the existing vaccines are good enough.”
Any decision to change vaccines or dosing must be based on research data, insisted Babu. “At present, there is no evidence to suggest any imperative to have more than three doses. Therefore, any changes in vaccine recommendations or distribution should be made based on careful analysis of the data of individuals who have received more doses compared with those who haven’t,” he said.