Figure 5

Resiliency of anti-spike antibody titer over time. Serum samples from two recovered COVID-19 patients were collected at 57, 92, 134, and 190 days post onset of symptoms (Individual 1, left) or at 68, 82, 159, 187, 208, 236, 264, and 292 days post onset of symptoms (Individual 2, right). Anti-spike antibody titers were measured by ELISA at 50, 150, 450, 1350, and 4050 times dilution in quadruplicate (Individual 1, Days 57 and 92; Individual 2, Days 68, 82, 159, and 187) or in duplicate (Individual 1, Days 134 and 190; Individual 2, Days 208, 236, 264, and 292). The average and standard deviation for each dilution of each sample is plotted, revealing detectable antibody titers at 1:450 dilution for more than 9 months post onset of symptoms for Individual 2, with the day of symptoms onset being day 0.