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Omicron science, good news
Umieść na stronie
- Opublikowany 29 gru 2021
- New science explains South Africa's low rates of omicron severe disease
SARS-CoV-2 spike T cell responses induced upon vaccination or infection remain robust against Omicron
Institute of Infectious Disease and Molecular Medicine, University of Cape Town
SARS-CoV-2 Omicron variant has multiple Spike (S) protein mutations
These contribute to escape from the neutralizing antibody responses,
reducing vaccine protection from infection
We assessed the ability of T cells to react with Omicron spike
In participants who were vaccinated with Ad26.CoV2.S (J and J) (n = 20)
or BNT162b2 (Pfizer) (n = 15
or in unvaccinated convalescent COVID-19 patients (n = 15)
SARS-CoV-2-specific T cells play a key role in modulating COVID-19 severity and provide protective immunity
70-80% of the CD4 and CD8 T cell response to spike was maintained across study groups
The magnitude of Omicron cross-reactive T cells was similar to that of the Beta and Delta variants
These results demonstrate that,
despite Omicron’s extensive mutations
and reduced susceptibility to neutralizing antibodies,
the majority of T cell response,
induced by vaccination or natural infection, cross- recognises the variant.
Well-preserved T cell immunity to Omicron,
is likely to contribute to protection from severe COVID-19,
supporting early clinical observations from South Africa.
The limited effect of Omicron’s mutations on the T cell response suggests that vaccination or prior infection may still provide substantial protection from severe disease.
Indeed, South Africa has reported a lower risk of hospitalisation and severe disease compared to the previous Delta wave
Cross-reactive T cell responses acquired through vaccination or infection may contribute to these apparent milder outcomes for Omicron.
The resilience of the T cell response demonstrated here also bodes well in the event that more highly mutated variants emerge in the future.