Fig. 7.

Memory T cell responses to SARS-CoV-2 in children and adults.

(A) Frequency of CD25⁺CD134⁺CD4⁺ T cells in cultures of PBMCs stimulated with recombinant SARS-CoV-2 RBD protein from children and non-ICU adults in Acute and Convalescent phases.

(B) Frequency of CD25⁺CD134⁺CD4⁺ T cells in cultures of PBMCs stimulated with recombinant SARS-CoV-2 Spike (S) protein from children and non-ICU adults in Acute and Convalescent phases.

(C) CD4⁺ T cell proliferative response in 14-day cultures of PBMCs stimulated with recombinant SARS-CoV-2 RBD protein from children and non-ICU adults in Acute and Convalescent phases.

(D) CD4⁺ T cell proliferative response in cultures of PBMCs stimulated with recombinant SARS-CoV-2 S protein from children and non-ICU adults in Acute and Convalescent phases.

(E) Linear regression of CD25⁺CD134⁺ response to RBD protein by CD4⁺ T cells with age in Acute (left) and Convalescent (right) phases. The magnitude of the memory response to RBD scales linearly with age in convalescent samples.

(F) Linear regression of CD25⁺CD134⁺ response to S protein by CD4⁺ T cells with age in Acute (left) and Convalescent (right) phases. The magnitude of the memory response to RBD scales linearly with age in convalescent samples.

(G) Linear regression of proliferative response to RBD protein by CD4⁺ T cells with number of SARS-CoV-2-specific naïve (left) and memory (right) T cells. The magnitude of the proliferative memory response to RBD scales linearly with age in convalescent samples.

(H) Linear regression of proliferative response to S protein by CD4⁺ T cells with number of SARS-CoV-2-specific naïve (left) and memory (right) T cells.