Last week, the WHO designated B.1.1.529 — named after the Greek letter “Omicron” — as a COVID-19 variant of concern (VOC).
The variant has alarmed public health experts due to its “very unusual constellations of mutations”. Because this incarnation of SARS-CoV-2 has so many changes — many of them novel — there are fears about increased transmissibility, immune system evasion, and possible resistance against vaccines.
Omicron was first detected in Botswana on November 9th 2021. Since then, it has also been reported in neighbouring South Africa, Belgium, Hong Kong, Israel, UK and several other countries.
Change is the Only Constant
Viruses mutate all the time. Most of these “copying errors” (aka genetic mutations) are harmless i.e. they don’t substantially change the structure of the virus. But if a virus continues to spread unabated, the probability of the pathogen developing more lethal mutations increases.
And lethal mutations can be really bad. Just look at Delta, which caused India’s devastating Second Wave and is currently the world-leading variant.
The WHO regularly monitors emerging new variants and classifies them as variants under investigation (VUI) and, should the mutations be significant, variants of interest (VOI). VOC are those whose features are likely to make them more dangerous and infectious than previous coronavirus iterations.
How Dangerous is Omicron?
The Network for Genomics Surveillance in South Africa (NGS-SA) has said that some of B.1.1.529’s alterations were earlier identified in the Alpha, Delta and Lambda variants; however, there are many that have “rarely [been] observed until now and not well characterised”.
Some of these mutations reportedly enable Omicron to replicate faster and enter the body’s cells more easily. The latter pertains to the at least 30 mutations in the region that encodes the spike protein, which is of particular concern since this is the part of the virus that vaccines are designed to target. Any drastic changes in structure of the spike protein — which the virus uses to gain entry into human cells — could render existing vaccines futile.
FYI: The new VOC has been detected in nearly 90% of cases in South Africa’s Gauteng province, where the test positivity rate has risen from under 1% to 30% in only three weeks.
It is likely to take a few more weeks before scientists can definitively ascertain vaccines’ effectiveness against Omicron. If early studies can be trusted, the new variant could make vaccines 40% less effective. Again, this figure isn’t peer-reviewed or conclusive: a more reliable picture will emerge in the coming weeks.
For now, there are fewer than 100 whole-genome sequences available. The WHO has implored countries to submit complete genome sequences and associated metadata to a publicly available database, such as GISAID, at the earliest. Studies commenced on Tuesday to analyse Omicron’s immune escape potential in a laboratory setting. South Africa has also established a real-time system to monitor hospitalisations.
Speaking of which, the country has seen a worrying jump in cases over the past month, coinciding with the discovery of B.1.1.529. And the proportion of Omicron genomes has skyrocketed at a pace faster than even Delta’s.
As we await more information from the WHO, it’s important to remember that, whatever you do…don’t panic!
