(A–G) Age (A), the percentage of male and female participants (B), the number of symptoms (sx) during acute infection (C), mean SARS-CoV-2 total anti-receptor binding domain (RBD) IgG levels (D), along with percentages of total CD56⁺ NK cells (E), CD56^dim/CD16⁺ NK cells (F), and CD56^dim NK cells expressing KIR2D (L1/S1/S3/S5) (G) approximately 4 months following acute infection in those with long COVID (LC) and those who fully recovered. (H and I) Spearman’s correlation analysis of CD56^dim/CD16⁺ NK cell percentages and the number of LC symptoms (H), and the percentage of CD56^dim/CD16⁺ NK cells in participants with neurocognitive (neuro), gastrointestinal (GI), fatigue, and cardiopulmonary (CP) LC (I) are shown. (J and K) CD56^dim/CD16⁺ NK cell percentages in male and female participants (J) and repeat CD56^dim/CD16⁺ comparisons, including only female participants (K). (L and M) NK cell cluster UMAP (L) and the percentage of adaptive NK cell clusters by LC symptom group, CMV IgG serostatus, and presence or absence of SARS-CoV-2 spike or nucleocapsid antigen in blood after COVID-19 (M). Mean (bars) and 95% confidence intervals are shown. P values are from 2-tailed Mann-Whitney U testing (I, J, and M) or Kruskal-Wallis testing (C, F, G, and K).