Non-vaccinated (a) (n=48)
Vaccinated
Vaccinated
P value
1 vaccine dose (b) (n=31) 2 vaccine doses (c) (n=317)
Age, mean (SD), yr* 87.2 (9.2) 85.1 (9.2) 87.6 (9.2) 0.22
Sex, n (%)** Female Male 35 (72.9) 13 (27.1) 25 (80.7) 6 (19.3) 252 (79.5) 65 (20.5)
0.56
Charlson index (median, IGR) [range] *
6.0 (5.0-7.0) 2-15 6.0 (5.0-8.0) 3-15 6.0 (5.0-7.0) 2-15
0.41
Prior SARS-CoV-2 positive RT-PCR, n (%)** 5 (10.4) 3 (9.7) 43 (13.6) 0.82
Positive RT-PCR during outbreak, n (%)**
21 (43.7)
10 (32.3)
72 (22.7)
0.0059 0.005 (a vs c)
N-protein IgG > 0.8 signal to cutoff ratio, n (%)*** 5 (20.0) 5 (17.9) 38 (14.0) 0.57
RBD-IgG level, AU/mL, median (IQR) *
n = 26 2 (1-415) n =28 534.00 (201.50 ; 2166.50) n =271 1522.00 (444.00 ; 5389.00) 0.000001 0.001 (a vs b) 0.01 (a vs c) 0.08: (b vs c)
Covid-19-related deaths, n (%)***
5 (10.4)
2 (6.4)
3 (0.9)
0.0007 0.004 (a vs c)