Is H3N2 virus life-threatening? Could it be another Covid? Experts respond

Amid increased concerns over the rising cases of the H3N2 influenza virus and two deaths caused by it, experts said the outbreak is normal. On the sudden spike in cases, doctor Dhiren Gupta of the Ganga Ram Hospital in Delhi said on Saturday Covid-induced lockdowns were the reason why there was no exposure of influenza to children in the past two years and that the virus is not life-threatening in normal circumstances.

"...because of this…the sudden outbreak of the H3N2 virus which is a normal variant of influenza variant has caused an increase in the number of cases in children," Gupta was quoted as saying by news agency ANI. Children and people with co-morbidities are the most vulnerable groups, affected by seasonal influenza.

"The H3N2 is antigenic drift and a mild mutation but is not life-threatening. Whichever virus it is, if there's comorbidity then the chances of death is high. The vaccine against H3N2 has less efficacy & our vaccination is low this year," he further said.

As concerns mounted and some people wondered whether this could possibly turn out to be another Covid, pulmonologist Anurag Agrawal said he doesn't expect to see a massive wave. "Admission to hospital has not been very common and only about 5 per cent cases have been reported to be hospitalised," news agency PTI quoted Tarun Sahani, senior consultant, internal medicine, Apollo Hospitals, as saying.

While there is no need to panic yet, Sahani said it is advisable to take precautions similar to those taken during Covid times.

"... if most of the infected people recover albeit slow, it should be fine," virologist Upasana Ray, alumni member of Indian National Young Academy of Science (INYAS) and member of Global Young Academy (GYA), told PTI.

She noted that lockdowns and extensive use of masks for extended periods of time helped control transmission of more virulent versions of the virus, but also prevented good exposure of regular seasonal respiratory viruses.

With cases on the rise, people are alarmed as the spread of virus has caused increased hospitalisations. A total of 3,038 laboratory-confirmed cases of various influenza subtypes, including H3N2, up until 9 March were recorded in the country, with one death each in Karnataka and Haryana.

H3N2 is a non-human influenza virus that normally circulates in pigs and has infected humans but experts said the seasonal flu which is usually detected in India during January- March and then after Monsoon, will see a decline after March. The government has recommended to follow Covid protocols and hygiene practices to avoid infection.

While influenza A (H1N1pdm09), Influenza A (H3N2) and Influenza B (Victoria) have been detected in India, H3N2 is the predominant subtype and has caused more hospitalisations. However, on its patterns, the government said that a larger number of patients showed only fever and cough symptoms, while about 27% presented with breathlessness, 16% with wheezing, 16% with pneumonia, and 6% with seizures. Roughly 10% of patients required oxygen, and 7% required ICU care.