Omicron - New Coronavirus Variant of Concern
A new coronavirus variant, known as B.1.1.529, was first reported to WHO on November 24. On 26 November, the World Health Organization (WHO) designated the strain, as a variant of concern and named it Omicron and joins Delta, Alpha, Beta and Gamma on the current WHO list of variants of concern.The strain was first reported from South Africa and has also been identified in Botswana, Belgium,
Hong Kong and Israel.
It is not uncommon for a virus to change, or mutate, over time. The variant of concern label is reserved for Covid mutations that are more contagious, more virulent and more skilled at evading public health measures, vaccines and therapeutics.
Scientists in South Africa and their counterparts across the globe are trying to characterize the molecular structure of the new variant inorder to assess it's transmissibility, virulence, severity of disease causation and it's response to immunity.
The new strain has roughly 50 mutations in total, including 10 to the receptor binding domain, the part of the virus that first comes in contact with cells. The highly contagious delta variant, which accounts for 99% of the world's Covid cases, has just two mutations to the receptor binding domain. The variant contains more than 30 changes to the spike protein — the SARS-CoV-2 protein that recognizes host cells and is the main target of the body’s immune responses. The spike protein is the chief target of human antibodies that the immune system produces to fight a coronavirus infection. So many mutations raised concerns that Omicron’s spike might be able to evade antibodies produced by either a previous infection or a vaccine. It is very concerning that many of these mutations could lead to increased antibody resistance and transmissibility, limiting the effectiveness of Covid vaccines.
Preliminary evidence suggests an increased risk of reinfection with this variant. The number of cases of this variant appears to be increasing in almost all provinces in South Africa.
So far, the threat Omicron poses beyond South Africa is far from clear. It is also unclear whether the variant is more transmissible than Delta.
It is too early to tell what kind of impact the mutations will have on vaccine efficacy. More studies also need to be conducted to understand the clinical severity of the variant compared to previous variants.
Individuals are reminded to take measures to reduce their risk of COVID-19, including. proven public health and social measures such as wearing well-fitting masks, hand hygiene, physical distancing, improving ventilation of indoor spaces, avoiding crowded spaces, and getting vaccinated.
The best tool we have is still the vaccines.