I wish someone had a magic stick who could take us back to the pre-COVID pandemic year and vanish this period when COVID emerged for the first time. But unfortunately, no such power exists in this world; therefore, every time we feel that we are on the verge of defeating this curse of the COVID-19 pandemic, a disappointment reaches us in the form of a new variant. Ultimately, after the tragic year of 2019 and 2020 in 2021, while every country was beating its own record of highest vaccination in a day, not so surprisingly, another variant of COVID-19 has evolved, which was first detected on 14th Nov 2021 in Botswana, South Africa. Today while I am writing about it, Omicron (B.1.1.529) has already spread to 38+ countries.
Nevertheless, everyone is frightened, panic and trying to know if this new variant known as Omicron is a villain or saviour? Meaning is this variant going to be deadlier than delta variant & other variants of concern or the mutation happened in this variant are least infectious, which will save us from most fatal delta variant by replacing/vanishing delta worldwide.
Before we reach any conclusion, let’s try to find out what is Omicron and other facts related to Omicron.
What is Omicron?
Omicron is another variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with an aggregate of 50 mutations, including 32 mutations on the spike protein, which is highest among all the variants of concern. On 26th Nov 2021, based on detrimental changes put forth by Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE), WHO declared Omicron as a variant of concern (VOC).
What is the reason for the development of Omicron?
In simple words, the viruses naturally have the ability to adopt any kind of environmental condition through an accumulation of changes in genetic material with a series of mutations. The same is true in the case of coronavirus, i.e. it has spread across the globe, causing numerous infections, therefore, more opportunities to accumulate mutations. That’s why we are encountering different strains and can’t help it.
How can we diagnose the Omicron variant?
This Omicron variant can be diagnosed with the currently used PCR test, as one of three target genes detected (S gene dropout), thus considered as a marker for this variant. Moreover, another assay like targeting specific (e.g. Δ69/70, N501Y) using PCR test can possibly be performed in Omicron, just like other variants of concern.
Is the Omicron variant more transmissible than the delta variant?
Although it is not clear whether Omicron spreads easily faster than other variants, following preliminary evidence points towards a higher transmissibility rate.
The three mutations around the furin cleavage site and some mutations outside of the spike protein (the nsp6 deletion Δ105-107) may be associated with increase transmissibility, replication, and evasion of innate immunity.
Higher growth rate
In South Africa delta variant is rapidly being replaced by the Omicron, which clue towards the higher transmissibility
Is vaccine effective against Omicron?
It’s too early to comment about vaccine effectiveness; however, high transmissibility also points to low immunity against this variant.
Six mutations in the N-terminal domain are suspected to evade antibody neutralization of innate, vaccine-based, or monoclonal-based antibodies.
Although no inference can be drawn from cases in South Africa since only 24% of the population is fully vaccinated, but according to the data of Omicron infection among travellers to the places where either negative certificate or proof of vaccination required, the detection of Omicron cases within the population fully vaccinated instigate towards the reinfection and questions the vaccine effectiveness.
Even WHO suspects risk of easy reinfection with Omicron among the people who previously had COVID-19, based on available preliminary data.
What are the Symptoms of Omicron?
So far, as per the CNBC report, “the South African doctors have confirmed that symptoms in new omicron variant are extremely mild”. In addition, the first person who detected Omicron positive had only a few symptoms of COVID-19 like body ache and pain with a bit of headache. Another patient infected with Omicron reported to have ‘mild scratchy throat’ but no cough, sore throat or loss of taste or smell.
What is the Severity of Omicron infection?
Depending on the genetic mutation information, the two nucleocapsid R203K and G204R mutations are associated with increased infectivity.
Three mutations in receptor binding domain T478K, N501Y, Q498R may increase the binding affinity of the virus to the ACE2 receptors on host cells.
So far, no death reported due to the infection with Omicron variant
In nutshell, the highest number of mutations noticed in Omicron refers to high transmissibility, high affinity for host cell binding, and antibody neutralization, possibly the reason for consideration in the category of the variant of concern. On the contrary, it’s been 20 days since the first case of Omicron detected, and since then, it has spread to 38+ countries, but no death reported yet. Moreover, the symptoms observed in the patient’s infected with Omicron are extremely mild.
on the one hand, depending upon the initial pieces of evidence about transmissibility and escape from vaccine, the risk factor presumed to be high to very high; on other hand, lack of known causality and extremely mild symptoms provides evidence that it might be highly contagious, but it is as good as a common cold.
Anything could be true; thus, our duty is not to panic too much or be relaxed; we should follow the COVID prevention guidelines to keep ourselves safe.
References
Assessment, B. R. (2021). COVID-19 Variant of Concern Omicron. 1–9.
Centre of Disease Prevention, E. (2021). Implications of the emergence and spread of the SARS-CoV-2 B.1.1. 529 variant of concern (Omicron) for the EU/EEA.
CNBC | Health and Science | South African doctor who first spotted the Covid omicron variant says symptoms seem ‘mild’ so far.
No deaths yet as Omicron grips 38 countries: WHO – The Hindu. (n.d.). Retrieved December 5, 2021, from https://www.thehindu.com/news/international/no-deaths-yet-as-omicron-grips-38-countries-who/article37842896.ece