||
Dr. Peacock proposed a new lineage——B.1.1.529
携带55个点突变的新冠变异株(其中32个突变位于SARS-CoV-2的刺突蛋白)。
LITERALLY THE WORST VARIANT I'VE EVER SEEN.
Earliest Sequence: 2021-11-11
Latest Sequence: 2021-11-13
Countries circulating: Botswana (3 genomes), 中国香港 ex S. Africa (1 genome, partial)
Description:
Conserved Spike mutations - A67V, Δ69-70, T95I, G142D/Δ143-145, Δ211/L212I, ins214EPE, G339D, S371L, S373P, S375F, K417N, N440K, G446S, S477N, T478K, E484A, Q493K, G496S, Q498R, N501Y, Y505H, T547K, D614G, H655Y, N679K, P681H, N764K, D796Y, N856K, Q954H, N969K, L981F
备注:Δ69-70表示69-70位的氨基酸缺失; ins214EPE表示214位插入EPE氨基酸。
Conserved non-Spike mutations - NSP3 – K38R, V1069I, Δ1265/L1266I, A1892T; NSP4 – T492I; NSP5 – P132H; NSP6 – Δ105-107, A189V; NSP12 – P323L; NSP14 – I42V; E – T9I; M – D3G, Q19E, A63T; N – P13L, Δ31-33, R203K, G204R
Currently only ten sequences so would recommend monitoring for now. Export to Asia implies this might be more widespread than sequences alone would imply. Also the extremely long branch length and incredibly high amount of spike mutations suggest this could be of real concern (predicted escape from most known monoclonal antibodies)
Genomes:
EPI_ISL_6590608 (partial RBD Sanger sequencing from Hong Kong, China)
EPI_ISL_6640916
EPI_ISL_6640919
EPI_ISL_6640917
The World Health Organization (WHO) currently lists B.1.1.529 as a “variant under monitoring”(VUM), which is below the agency’s classification of “variants of interest”(VOI) and “variants of concern” (VOC).
The B.1.1.529 strain, an offshoot of an old variant called B.1.1, has 32 spike mutations and has been found in South Africa, Botswana and one case in Hong Kong,China, where the person had recently travelled to South Africa.
So far only 10 cases of the variant have been spotted through genomic sequencing, but scientists say there could be more not yet identified. The profile of mutations is concerning due to its potential to dodge antibodies that can fight the virus.
The new variant was identified on Tuesday by Tom Peacock, a virologist at Imperial College London, who posted the details on a sequence-sharing forum and on Twitter.
The variant’s 32 spike mutations is described as “extremely high”. The Delta variant, now dominant across the world, has 16.
Spike mutations are essentially the virus’ “bag of tricks” that allow it to adapt and do different things such as become more transmissible, escape vaccines or become more deadly. It is not known whether B.1.1.529 is more transmissible or could beat Delta’s dominance.
Dr Peacock wrote: “Export to Asia implies this might be more widespread than sequences alone would imply. Also the extremely long branch length and incredibly high amount of spike mutations suggest this could be of real concern (predicted escape from most known monoclonal antibodies).”
Dr Peacock described the spike mutation profile as “really awful” and “horrific”.
He added: “Worth emphasising this is at super low numbers right now in a region of Africa that is fairly well sampled, however it very very much should be monitored due to that horrific spike profile (would take a guess that this would be worse antigenically than nearly anything else about).”
Variants that mutate to become more antigenic are more able to evade the antibodies that are built up through immunity from either vaccines or previous infection.
It is understood that all governments where the variant has been identified, in South Africa, Botswana and Hong Kong, China, are aware of the cases.
Dr Meera Chand, Covid-19 Incident Director at UKHSA, said: “The UK Health Security Agency, in partnership with scientific bodies across the globe, is constantly monitoring the status of SARS-CoV-2 variants as they emerge and develop worldwide.
“As it is in the nature of viruses to mutate often and at random, it is not unusual for small numbers of cases to arise featuring new sets of mutations. Any variants showing evidence of spread are rapidly assessed.”
参考资料:
B.1.1 decendant associated with Southern Africa with high number of Spike mutations
Covid ‘super variant’ with 32 mutations found with cases in South Africa, Botswana and Hong Kong, China (南非惊现新冠病毒“超级突变”)
Archiver|手机版|科学网 ( 京ICP备07017567号-12 )
GMT+8, 2024-11-23 12:13
Powered by ScienceNet.cn
Copyright © 2007- 中国科学报社