Bimodal antibody-titer decline following BNT162b2 mRNA anti-SARS-CoV-2 vaccination in healthcare workers of the INT – IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy)

Table 4 Antibody titers’ fold changes (FC) in previously infected and not previously infected cohorts of healthcare providers to monitor vaccine immune responses

Analyzed cohorts	Mean FC	Min FC	Max FC
Previously infected subjects
T1 − T0	2.0	1.5	1.9
T2 − T1	0.1	− 0.1	0.2
T2 − T0	2.1	1.5	3.1
T3 − T2	− 0.6	− 0.6	− 0.5
T6 − T3	− 0.2	− 0.2	− 0.2
T9 − T6	− 0.2	− 0.2	− 0.1
T boost − T6	1.5	1.5	1.5
T boost − T9	1.7	1.7	1.7
T boost − T2	0.7	0.7	0.8
T boost − T0	2.3	2.3	2.4
Not previously infected subjects
T1 − T0	1.6	0.6	2.4
T2 I − T1	2.0	1.3	3.0
T2 II − T2 I	− 0.4	− 0.7	− 0.2
T2 I − T0	− 0.3	− 0.5	− 0.1
T3 − T2 II	− 0.2	− 0.5	0.1
T6 − T3	− 0.1	− 0.3	0.0
T9 − T6	− 0.1	− 0.3	0.0
T boost − T6	1.7	1.2	2.6
T boost − T9	1.9	1.3	2.6
T boost − T2 I	0.9	0.4	1.3
T boost − T2 II	1.2	0.7	1.8
T boost − T0	4.5	4.1	4.9

Previously infected subjects = subjects previously infected with SARS-CoV-2, Not previously infected subjects = subjects not infected with SARS-CoV-2, For previously infected subjects: T0 = baseline pre-vaccination after SARS-CoV-2 infection, T1 = 8 days after the unique dose, T2 I = 1 month after the unique dose, T3 = 3 months after the unique dose, T6 = 6 months after the unique dose, T9 = 9 months after the unique dose, T boost = 8 days after the administration of a further boost dose. For not infected subjects: T0 = baseline pre-vaccination, T1 = 20 days after the first dose, T2 I = 8 days after the second dose, T2 II = 1 month after the second dose, T3 = 3 months after the second dose, T6 = 6 months after the second dose, T9 = 9 months after the second dose, T boost = 8 days after the administration of boost dose, mean FC = mean fold changes of anti-SARS-CoV-2 S mean geometric titers, min FC = minimum value of fold changes of anti-SARS-CoV-2 S mean geometric titers, max FC = maximum value of fold changes of anti-SARS-CoV-2 S mean geometric titers, n = number of subjects

ISSN: 1750-9378