Coronavirus Explained: Three common Omicron variants, their symptoms and why they shouldn’t be taken lightly

Omicron is the latest variant of concern and currently accounts for the majority of the COVID-19 infection worldwide. The Omicron variant of concern is currently the dominant variant circulating globally, accounting for nearly all sequences reported to GISAID, the World Health Organisation (WHO) said on Tuesday.

In a press briefing, the WHO's Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE) talked about the various sub variants of the Omicron and why they should not be taken lightly.

Omicron or the B.1.1.529 variant is the successor of the Delta variant. It is made up of several sub lineages and the most common ones among them are the BA.1, the BA 1.1. and the BA.2, the WHO said. The BA.2 sub variant is the main concern among researchers and health experts right now. There is also a BA.3 Omicron sub variant.

In the past few weeks, a large number of cases linked to the BA.2 Omicron sub variant have been reported.

On November 26, Omicron was declared as a variant of concern due to several factors: increase in transmissibility or detrimental change in COVID-19 epidemiology; increase in virulence or change in clinical disease presentation; decrease in effectiveness of public health and social measures or available diagnostics, vaccines, therapeutics. It had also warned that overall risk related to Omicron is very high, though milder symptoms were seen in many patients.

This is the first sub variant of the Omicron variant which was seen after the Delta variant of the coronavirus. The BA.1 lineage, which accounted for 97.4% of sequences submitted to GISAID as of 19 January, has the 69-70 deletion in the spike protein.

The common symptoms of Omicron induced COVID infection are: sore throat, cold, runny nose, sneezing, headache, body ache and mild fever. Symptoms like loss of smell and taste, which was predominant during the second wave of the coronavirus infection, was not seen during the Omicron wave.

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As per a research study BA.1.1 has 40 mutations. This along with the three other lineages were discovered in South Africa. According to the study, on February 10, 2022, when BA.2 accounted for 1% of the total infections, BA.1.1. was already detected in 69 countries.

The symptoms of the BA.1.1 sub variant are not distinct from that of the other variants.

"BA.2 differs from BA.1 in its genetic sequence, including some amino acid differences in the spike protein and other proteins. Studies have shown that BA.2 has a growth advantage over BA.1. Studies are ongoing to understand the reasons for this growth advantage, but initial data suggest that BA.2 appears inherently more transmissible than BA.1, which currently remains the most common Omicron sublineage reported,” the WHO said.

“This difference in transmissibility appears to be much smaller than, for example, the difference between BA.1 and Delta. Further, although BA.2 sequences are increasing in proportion relative to other Omicron sublineages (BA.1 and BA.1.1), there is still a reported decline in overall cases globally,” it added.

Said to be the fastest spreader among all the super-spreader Omicron sub variants, the BA.2 induced COVID infection causes symptoms like runny nose, sore throat, difficulty in breathing, persistent cough, fatigue. No other distinct symptoms have been reported for Omicron sub variant infection, other than the findings of few research studies which say that Omicron sub variant can cause severe damage to the lungs.

The immune escape ability of this sub variant is often linked with the severity of the disease however, as told by WHO, this sub variant is similar to the other sub lineages of Omicron in terms of severity.

Also Read: WHO says Omicron severity same as original strain

The occurrence of COVID symptoms varies from person to person. The degree of severity of the COVID infection depends on how the body’s immunity mechanism reacts to the pathogenic attack.

In many patients, the infection is leaving a mark which is showing even months after the recovery.

"Omicron has replaced the Delta variant at a global level. Many countries have passed their peak but not all countries have passed their peak. It is less severe than Delta but it is not a mild virus,`` Maria Van Kerkhove, who leads the technical side of the WHO's COVID-19 response team, said.

On the fundamental similarities between BA.1 and BA.2, Dr Anurag Agrawal, Chair of TAG, SARS-COV-2 virus evolution has said that, "BA.2 is already a variant of concern. The similarity of fundamentally high transmissibility, less severity, ability to evade vaccines were roughly similar based on available data. We did take all data into account and have concluded that for the time being, the Omicron label is a sufficient label for both BA.1 and BA.2 sub variants.”

Coronavirus has killed more than 5.8 million people worldwide, according to an AFP tally compiled from official sources on Tuesday.

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