On 25 November, South Africa announced that it was tracking a new variant, B.1.1.529/Omicron, and shared the following:
- New variant detected in South Africa (lineage B.1.1.529) with high number of mutations, which are concerning for predicted immune evasion and transmissibility
- B.1.1.529 genomes produced from samples collected 12-20 Nov from Gauteng, SA (n=77), Botswana (n=4) and Hong Kong (n=1, traveler from SA)
- B.1.1.529 can be detected by one particular PCR assay (before whole genome sequencing)
- Early signs from diagnostic laboratories that B.1.1.529 has rapidly increased in Gauteng and may already be present in most provinces
- Mutation profile predicted to give significant immune evasion and enhanced transmissibility
See also these three assessments by the UK HSA, Belgian NRL, and WHO respectively.
Some have suggested that SARS-CoV-2 vaccines may have to be updated to target the Omicron variant in particular, given that its unique constellation of mutations may result in lower vaccine- and infection-elicited antibody neutralization. Vaccine producers including Moderna, Pfizer/BioNTech, Janssen, and Novavax have said they are testing their vaccines against the new variant. Moderna has announced it is advancing an Omicron-specific booster candidate.