Table 3.

Bivariate analysis of the correlates of anti-S IgG antibody levels at the follow-up assessment among participants without reinfection.

	Number interviewed	Number tested for IgG anti-S	Geometric mean concentration (95% CI)	P-valuea
Age, years
18-34	491	82	412 (291-583)	0.473*
≥35	384	122	503 (341-741)
Sex
Males	688	173	467 (345-633)	0.913*
Females	187	31	448 (258-777)
Fever at primary infection
<38°C	225	62	481 (274-843)	0.433*
≥38°C	350	77	622 (428-903)
Hospitalization at primary infection
Yes	133	38	656 (370-1164)	0.226a
No	742	166	429 (316-582)
Anti-N at primary infection
Negative & Positive - up to 4	509	96	234 (147-372)	<0.001a
Positive 4+	366	108	854 (664-1098)
COVID-19 vaccination status
0 doses	100	30	38 (14-100)	<0.001a
1+ doses	775	174	716 (579-885)
COVID-19 vaccination status
0 doses	100	30	38 (14-100)	<0.001b
1 dose	402	79	603 (431-844)
2 doses	303	72	802 (578-1113)
3+ doses	70	23	906 (551-1489)
Time from 1st vaccine to anti-S testing, months		128	r = -0.084c	0.345
Time from primary infection to anti-S testing, months		194	r = 0.293c	<0.001

CI, confidence interval; Ig, immunoglobulin; S, spike.

^aP-value was obtained by Student's t-test or ^bindependent sample Kruskal-Wallis test

^cSpearman correlation coefficient