IGHE and myalgic encephalomeyelitis/chronic fatigue syndrome: Almost all individuals of this group (pHBD) had values over the cut-off for IgG and IgE against SARS-CoV-2 spike, which were statistically different in comparison to pre-pandemic controls (ppHBD + CFS) (p<0.0001 and p<0.001, respectively; right plots in Figures 2A, D), while very few IgA values and no IgM level surpassed the set cut-off values (right plots in Figures 2B, C).