What is Omicron? The new B.1.1.529 variant (Omicron) clade 21K, which harbors many mutations, particularly in the spike protein, was first detected in South Africa. Unlike the other variants of concern, B.1.1.529 has emerged independently from mid-2020 strains of SARS-CoV-2.
Why South Africa? It is possible, but unlikely, that this variant emerged in South Africa. South Africa has excellent scientists, a great surveillance program, transparency, and sharing of data!
Anytime there's a new variant of SARS-CoV-2, there are at least 4 concerning things to consider: 1) Is it more transmissible than currently circulating strains? 2) Does it evade neutralization by antibodies (i.e., antibodies from natural infection, immunization, or monoclonal antibodies)? 3) Does it evade immunity due to vaccination (i.e., antibodies, T cell response)? 4) Does it cause a more severe (or milder) disease?
1) Is it really more transmissible than Delta? It's too soon to tell. Superspreader events, which are outliers, get noticed early and can result in a very high estimation of basic reproduction number (R0). However, it does seem like B.1.1.529 (Omicron) is outcompeting B.1.617.2 (Delta) in South Africa.
2) Does it evade neutralization by antibodies? Omicron seems to have many more S1 mutations than previously circulating variants, which might be very problematic. While we don't know for sure yet, its mutation profile predicts significant immune evasion.
3) Does it evade immunity due to vaccination (i.e., antibodies, T cell response)? We don't know yet.
4) Does it cause a more severe (or milder) disease? We don't know yet.
We need more studies to understand this variant and its impact more. In the meantime, please get vaccinated and wear a mask!
[All images from IDTwitter]
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