Figure 3.

Acute and memory CD4⁺ T cell responses after mRNA-1273, BNT162b2, Ad26.COV2.S, or NVX-CoV2373 immunization

(A) Longitudinal spike-specific CD4⁺ T cell responses induced by four different COVID-19 vaccines measured by OX40⁺CD137⁺ AIM⁺ after spike megapool (MP) stimulation. See Figure S2B for the representative gating strategy of OX40⁺CD137⁺ AIM⁺ cells.

(B) Longitudinal spike-specific CD4⁺ T cell responses induced by four different COVID-19 vaccines measured by OX40⁺ surface CD40L⁺ AIM after spike megapool (MP) stimulation. See Figure S2C for the representative gating strategy of OX40⁺sCD40L⁺AIM⁺ cells.

(C) Longitudinal spike-specific circulating T follicular helper cells (cTfh) induced by COVID-19 vaccines. Spike-specific cTfh cells (CXCR5⁺OX40⁺sCD40L⁺, as % of CD4⁺ T cells) after stimulation with spike MP. See Figure S2D for the representative gating strategy of cTfh cells.

(D–F) Comparison of spike-specific CD4⁺ T cells by OX40⁺CD137⁺ AIM⁺ (D), OX40⁺sCD40L⁺AIM⁺ (E), and cTfh (F) between COVID-19 vaccinees at 185 ± 6 days post-vaccination and SARS-CoV-2-exposed subjects 170 to 195 days PSO. Data are represented as geometric mean ± geometric SD.

The dotted black line indicates the limit of quantification (LOQ). The color-coded bold lines in (A), (B), and (C) represent the geometric mean each time post-vaccination. Background-subtracted and log data analyzed. p values on the top in (A), (B), and (C) show the differences between each time point in the different vaccines and are color-coded as per Figure 1. Bottom bars in (A), (B), and (C) show fold-changes between T3 and T5. Data were analyzed for statistical significance using the Mann-Whitney test ([A–F]). NS, non-significant.

See also Figure S2.