In 2020, T cells were largely ignored w/r to covid infections.
In 2021, T cells are being largely ignored w/t to covid vaccinations.
In part, because they are rarely assessed.
A review of some recent studies /1

Lack of effect of variants on T-cell responses /2
https://www.biorxiv.org/content/10.1101/2021.02.27.433180v1

The strong vaccine-induced T-cell response in people with prior covid @TheLancet
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00502-X/fulltext /3

Vaccine-induced spike-specific T cell activation at 10 days coincident with established protection
https://www.cell.com/med/fulltext/S2666-6340(21)00152-5 @MedCellPress /4

Rapid, robust CD4+ T cell response to 1st dose vaccination, gradual CD8+ increase. Both up in people w/o prior covid but little added T cell boost after 1 dose in people with prior covid
https://www.biorxiv.org/content/10.1101/2021.04.21.440862v1 @markmpainter @WherryLab @EJohnWherry @divijmathew @rishirajgoel /5