No evidence of new Covid variant’s severity: Experts

XBB.1.16 has become the predominant variant of the Sars-CoV-2 in India, according to genome sequence analysis released by Indian experts, who said the emergence has not been correlated with any worrying signs in severity, even though there has been a slight up tick in recorded cases.

The increase in recorded cases — India recorded an average of 966 new cases on Wednesday, compared to 520 a week before — prompted the government to go into a huddle and review the situation. Prime Minister Narendra Modi urged states and federal authorities to keep up adequate vigil on the nature of the virus circulating and behaviour patterns of people.

“While cases are rising slightly, there is no evidence of an increase in hospitalization or death that is usually a cause for concern,” said a senior official in the central government, requesting anonymity, adding that the disease is likely progressing towards becoming endemic.

According to the government, eight states— Maharashtra (4.49%), Gujarat (2%), Kerala (4.17%), Karnataka (3.08%), Tamil Nadu (2.26%), Delhi (3.76%), Himachal Pradesh (7.1%) and Rajasthan (1.43%)— are showing a rising trend in test positivity ratio, taking the overall average of this number to 1.08%. In February, country’s average weekly case positivity was 0.09%.

The numbers are not alarming by themselves and some experts believe that more people are testing themselves because of a flu virus that is going around, and that some of them are testing positive for Covid-19.

Former AIIMS-Delhi, director, Dr Randeep Guleria, also said that there was no need to panic as long as it did not lead to severe illness.

“As long as they don’t lead to severe illness, hospitalisation and deaths, it is alright because it helps in giving some degree of immunity to the population if they have mild illness,” he said.

Of all the Covid positive samples whole genome sequenced between January 1 and March 23, 344 tested positive for XBB.1.16, followed by 196 positive samples of XBB.1.5, and 146 samples of XBB.2.3 sub-variants.

“It has been established already that XBB.1.16 has high transmissibility as compared to its predecessors, but its clinical severity is yet to be scientifically established. The research is on globally and our experts are also working on it. So far, however, there is no evidence to suggest that this subvariant causes more severe disease,” said another senior government official, requesting anonymity.

According to experts, XBB.1.16 is a recombinant strain of the virus that has descended from the XBB sub-variant, and is closer to XBB.1.5 with respect to the number of mutations accumulated. It has a greater growth advantage over other sublineages.

According to the INSACOG document, accessed by HT, all currently circulating variants are sub-variants of Omicron.

In Maharashtra, 105 positive samples for XBB 1.16 were found in Pune, Thane, Mumbai, Amravati, Nandurbar, Aurangabad, Sangli, and Ahmednagar. In Telangana, 93 samples tested from Adilabad and Asifabad. Karnataka reported 57 samples from Shivamogga, Bengaluru Urban, Chitradurga, Mysuru, Davanagere, Kalaburagi, and Ballari. Gujarat’s 54 samples were reported from Ahmedabad, Surat, Vadodara, and Rajkot. Nineteen positive samples were reported from Delhi.

“As the virus becomes endemic, it generates large number of variants. Since emergence of Omicron in 2021, close to 1,000 PANGO lineages have been assigned which include approximately 100 recombinant variants. Most of assigned variants have very little or no significant impact on the functional attribute of the virus like increased transmissibility, disease severity or immune escape etc.,” reads the INSACOG document.

“Only few of the variants/subvariants are designated as VOCs, VOIs or SUM (Subvariant under monitoring) based on scientific evidence on their transmissibility, disease severity or immune escape properties. XBB.1.5 or XBB.1.16 are VOIs which are under intense scientific scrutiny, but not cause of immediate concern.”

Doctors are more concerned by influenza, which has laid many people low, sometimes for as long as a month, primarily because of their lower immunity following an attack of Covid-19. Flu shots are also not common in India, although doctors have been encouraging people to take an annual one.