In brief:
- new SARS-CoV-2 variant detected
- more mutations than Delta
- spreads faster
- puts effectivity of current COVID-19 vaccines in question
- can potentially cause more severe symptoms
A new strain of SARS-Cov-2, the virus that causes COVID-19 has been documented in South Africa. We don’t have a lot information about it yet but experts in WHO have declared that this is a variant of concern (VOC).
The new variant designated as B.1.1.529 and named Omicron was first reported to WHO on 24 November 2021 from a specimen collected on 9 November 2021. It has 32 mutations in the spike protein, the part of the virus that it uses to attach itself to the host cells to gain entry. This is almost double than the 13-17 mutations in the Delta variant. Some of these mutations have not been seen before so their dynamics and interactions with the other known mutations is still uncertain. As such, it is considered to be the most complex variant as of today.
The Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE) has advised WHO to designate this variant as a VOC. According to CDC, a VOC has the following attributes:
Specific genetic markers that are predicted to affect transmission, diagnostics, therapeutics, or immune escape. (32 mutations)
Evidence that it is the cause of an increased proportion of cases or unique outbreak clusters. (This is observed in provinces in South Africa.)
Evidence of impact on diagnostics, treatments, or vaccines. (Omicron seems to be detected at a faster rate).
Widespread interference with diagnostic test targets. (Omicron seems to have growth advantage.)
Evidence of substantially decreased susceptibility to one or more class of therapies. (It has 32 mutations in the spike protein, the part of the virus that most vaccines use.)
Evidence of significant decreased neutralization by antibodies generated during previous infection or vaccination. (South African scientists reported this.)
Evidence of reduced vaccine-induced protection from severe disease. (Studies are underway to put this in full context.)
Evidence of increased transmissibility. (Studies are underway to put this in full context.)
Evidence of increased disease severity. (Studies are underway to put this in full context.)
WHO is asking countries to observe the following:
surveillance and sequencing efforts to better understand circulating SARS-CoV-2 variants.
complete genome sequences and associated metadata to a publicly available database, such as GISAID.
initial cases/clusters associated with VOC infection to WHO through the IHR mechanism.
capacity exists and in coordination with the international community, perform field investigations and laboratory assessments to improve understanding of the potential impacts of the VOC on COVID-19 epidemiology, severity, effectiveness of public health and social measures, diagnostic methods, immune responses, antibody neutralization, or other relevant characteristics.
As before, everyone is encouraged to observe the proven safety protocols in preventing infection and transmission of COVID-19 -- wearing appropriate masks, washing/sanitizing hands, physical distancing, improving ventilation of enclosed spaces, avoiding crowded spaces, and getting vaccinated.
WHO will continue to post regular updates on this developing story.
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