Figure 3. SARS-CoV-2 Spike–Specific Cellular Immune Responses in Vaccinated Pregnant, Lactating, and Nonpregnant Women.

Peripheral blood mononuclear cells (PBMCs) following 2 doses of vaccines were stimulated with SARS-CoV-2 USA-WA1/2020 spike peptides. The T-cell responses were measured using IFN-γ enzyme-linked immunospot (ELISPOT) assays and multiparameter intracellular cytokine staining assays to assess IFN-γ total CD4 T cells, CD45RA⁻ CD27⁺ central memory CD4 T cells, total CD8 T cells, and CD45RA⁻ CD27⁺ central memory CD8 T cells.

The red bars indicate the median and the dotted lines, the limit of detection. See Table 2 for an explanation of ELISPOT and ICS assays.