Figure 5.

B.1.617.2 challenge induces an anamnestic T cell response in the periphery of vaccinated NHPs

(A–E) Peripheral blood mononuclear cells (PBMCs) collected at weeks 0, 6, 25, and 42 post-immunization and days 2, 4, 7, and 14 post-challenge. Cells were stimulated with SARS-CoV-2 S1 and S2 peptide pools and then measured by intracellular cytokine staining (ICS).

(A and B) Percentage of memory CD4⁺ T cells with (A) T_H1 markers (interleukin [IL]-2, tumor necrosis factor [TNF], or interferon [IFN]γ) or (B) T_H2 markers (IL-4 or IL-13) following stimulation.

(C) Percentage of CD8⁺ T cells expressing IL-2, TNF, or IFNγ.

(D and E) Percentage of T_FH cells that express (D) CD40L or (E) IL-21.

(F–H) BAL fluid was collected at weeks 6, 25, and 42 post-immunization and days 2, 4, 7, and 14 post-challenge. Lymphocytes in the BAL were stimulated with S1 and S2 peptide pools and responses measured by ICS using T_H1 (F), T_H2 (G), and CD8 (H) markers. Samples from weeks 6 and 25 were only stimulated with S1 peptides.

Circles in (A)–(H) indicate individual NHPs. Boxes represent interquartile range with the median denoted by a horizontal line. Dotted lines set at 0%. Reported percentages may be negative due to background subtraction. 4–8 NHPs per group. Statistical analysis shown for mRNA-1273 cohort only.

See also Figures S3 and S4.