Omicron subvariants behind fresh Covid-19 surge in South India

The same day, Tamil Nadu reported 649 cases, taking its active case tally to 6,631, while Telangana reported 507 cases, taking its active case tally to 2,997.

Health department reports state that the surge in Covid-19 cases in Telanagana is due to BA.2.75, also known as the Centaurus subvariant of Omicron.

The dominant subvariant in Tamil Nadu is BA.5.2, while that in Karnataka is the BA.2 variant of Omicron.

According to Rajnarayanan, the most prevalent subvariant active in India are BA.2.75 (33.14 percent) followed by BA.5.2 (14.49 percent) and BA.2 (12.16 percent).

He added that the Omnicron subvariants active in the country were found in the genome sequencing conducted between 3 August and 17 August.

#COVID19 #VariantDashboard – #India

Top Circulating Lineages (#30DayTrends):

33.14% – BA.2.75 ?
13.49% – BA.5.2
12.16% – BA.2 ?
8.30% – BA.2.76
6.74% – BA.5.2.1
5.59% – BF.3
5.48% – BA.2.38
3.46% – BA.2.38.1

Tracker: https://t.co/M4Cq3Ob9MM

Updated 08/17/22

— Raj Rajnarayanan (@RajlabN) August 17, 2022

BA.2.75

The World Health Organisation (WHO) has described BA.2.75 as a variant of concern. BA.2.75 is the sublineage of the BA.2 subvariant of Omicron.

Out of the total 575 genome-sequencing samples sent from Telangana, 144 were found to be affected with BA.2.75 subvariant.

Telangana has reported the highest number of patients suffering from this subvariant in the country, followed by Karnataka with 58 cases and Tamil Nadu with 26 cases.

BA.5.2

Out of 234 samples of BA.5.2 in genome sequencing, Tamil Nadu has reported 87 cases, followed by Karnataka with 45 cases, and Telangana with 39 cases.

BA.2

Out of 211 samples of BA.2 in genome-sequencing samples, Karnataka reported 105 cases, followed by Telangana with 26 cases, and Tamil Nadu with five cases.

Apart from these major variants, Tamil Nadu has also reported 63 samples of BF.3, and 30 samples of BA.5.2.1.

Telangana has reported BA.2.76 (16 cases) and BA.5.2.1 (34 cases) subvariants of Omnicron.

Subvariants escape antibody response

According to medical experts, BA.2.75 and BA.5.2 easily escape antibody responses of people previously infected with Covid-19 and of those who have been fully vaccinated and boosted.

“We all are vaccinated. We already have immunity to defend ourselves from Covid-19. Now, variants are managing to escape the immunity and this is concerning,” Dr Rakesh Mishra, former director of CCMB, told South First.

He added, “Viruses evolve over the course of time. They learn how to escape immunity. But the main concern is how much it impacts people.”

Mishra also said that the recent variants BA.5 or BA.2.75 can infect human cells better.

“They also have mutations that may lower our antibodies’ ability to neutralise the virus. It is a concern that these variants of the virus may spread fast and evade immunity from vaccination or prior infection,” Mishra said.

Tamil Nadu Public Health Director Dr TS Selvavinayagam told South First, “We have seen the spread of Omicron subvariants. The severity of infection remains low in this variant. However, health agencies have buckled up on tracing and testing people and ensuring Covid-19 behaviours are being followed.”

Clinical virologist Dr Jacob John told South First, “The virulence of BA.4 and BA.5 is no different from the BA.1 and BA.2 lineages of Omicron. Individuals with comorbidities like high diabetes, obesity, and chronic illness, and those aged over 70 years should take extra care.”

Get boosted

Studies indicate that the third dose of the Covid-19 vaccine boosts immunity to Omicron variants 20-fold compared to a two-dose regimen.

“The symptoms after getting sick from new variants are the same as previous variants. The only solution to not getting infected or getting seriously sick is by getting a booster dose. It will boost immunity,” Mishra said.