Omicron likely to cause re-infections, surge in cases, say experts

Public health experts feel that India is better prepared now for surveillance, testing and care

As more suspect cases of Omicron are isolated across the country, experts say a significant surge is likely due to reinfections and even vaccinated people getting infected. V Nagarjuna Maturu, consultant pulmonology and sleep medicine, Yashoda Hospitals, Hyderabad, said the Omicron variant is definitely more transmissible than Delta. 

This is evident from the steep rise in cases in South Africa. There, Omicron has overtaken Delta as the predominant strain in circulation. “There is a definite possibility of a third wave in the country, as the variant has already been isolated from India. As the variant has multiple mutations on the spike protein region, it is theoretically possible that even vaccinated individuals may get infected,” Maturu said, adding that studies are going on to assess the effectiveness of the vaccines against Omicron.

On whether there will be a third wave due to Omicron, the health ministry said that the magnitude of rise in cases and the severity are still not clear.

Experts like Jacob John, senior virologist and former head of the departments of clinical virology and microbiology at Christian Medical College, Vellore, said that one can expect breakthrough infections.

“We can expect breakthrough infections due to this virus. Omicron may be escaping part of the immunity. For Beta and Delta variants, the response of the vaccine was less than the original variant. For Omicron, this will be even lesser. Omicron has all the mutations of Alpha, Beta, Gamma, Delta and itself. It is a peculiar virus. It is likely to evade immunity even for a vaccinated person, and therefore, we need booster doses,” he said. So far, mild to moderate symptoms have been noticed among Omicron patients.

Viswesvaran Balasubramanian, consultant interventional pulmonology and sleep medicine, Yashoda Hospitals, Hyderabad, said that evolving evidence suggests that the severity of infection induced by this variant is not critical. 

“Emerging evidence suggests that the virus is causing only mild to moderate illness with sore throat, body pains, fever and dry cough being predominant symptoms. It is also observed that loss of taste and smell are not that common in this variant,” he added. The Centre, too, has noted that the severity of the disease due to Omicron is anticipated to be low. This is due to the fast pace of vaccination and high exposure to Delta variants as shown by high seropositivity.

“The limited information that is available shows that there has not been severe illness or spate of admissions in ICUs. We have not heard of a death due to Omicron or surge in hospitalisation,” K Srinath Reddy, president, Public Health Foundation of India (PHFI), said. 

Reddy said India has had substantial exposure to the Delta variant and acquired natural infection immunity, which is much more broad based to deal with variants that evade anti-spike antibodies. 

John said, “The virus is inside India now. We need to be careful. Omicron is not likely to wreak havoc in India, because our natural infection-led immunity is strong. We have natural immunity for 90 per cent of people, stronger than vaccine-induced immunity.” 

Public health experts like Reddy feel that India is better prepared now for surveillance, testing and care.

“Our systems are also better placed today in terms of homecare, surveillance, and testing. Hospitals are geared up for a faster response now,” Reddy said, highlighting a few factors that may help India in tackling Omicron. 

According to virologists, it is a natural progression for a virus to become more infectious and less virulent. However, could Omicron be the final stop in the journey of coronavirus?  “We do not know. There could be further stops. We are being careless and giving viruses a smooth ride when we should try to give them a bumpy one. Why should a virus give up its virulence? We have to make it change its behaviour by adapting ourselves,” Reddy added.