Fig. 3
From: A cohort study measuring SARS-CoV-2 seroconversion and serial viral testing in university students
Semester start and end IgG serology index values for students with only negative viral tests during the semester. A Students with baseline positive serology and negative viral tests reported during the semester. Anti-N IgG index values are shown. B Students with negative baseline serology and negative viral tests reported during the semester. The horizontal dotted line at index value of 1.4 indicates the threshold for positivity. C Anti-S results from students with negative viral tests reported during the semester. D As in B, anti-S results in students with negative test results reported during the semester. Horizontal dotted line at 50 AU/mL represents the threshold of positivity