FIGURE 8. Comparison of anti-N and anti–S1-RBD Ab responses in natural infections versus vaccination.

Serum anti-N and anti–S1-RBD Ab responses were measured in 18 subjects 13–28 d after the first dose (n = 13) and 4–8 d after the second dose (n = 7) of COVID-19 vaccination and compared against responses in the 69 naturally infected COVID-19 convalescent patients from Fig. 4 (mild/moderate patients represented as blue squares; severe/critical patients represented as red diamonds). Two of the eighteen vaccinated subjects had both a dose 1 and dose 2 sample. Two of the thirteen vaccine dose 1 (VD#1) subjects received the Moderna vaccine; the remaining 11 subjects received the Pfizer vaccine. All seven of the vaccine dose 2 (VD#2) subjects received the Pfizer vaccine. Dashed lines indicate the C₀ (from Fig. 1).