Dynamics of SARS-CoV-2 antibodies after natural infection: insights from a study on Pasteur Institute of Tunis employees

Figures & data

Table 1. Characteristics of participants (n = 137).

Variables	n (%)
Sex
Male	34 (24.8)
Female	103 (75.2)
Age (years)
<40	53 (38.7)
≥40	84 (61.3)
Profession
Scientific staff*	17 (12.4.)
Administrative staff	87 (63.5)
Others^$	33 (24.1)
Comorbidities
Yes	63 (46.0)
No	74 (54.0)
Tobacco consumption
Yes	16 (11.7)
No	121 (88.3)

*Post doc, medical doctor, Doctor in pharmacy.

^$Technicians, laborers.

Table 2. Correlation between neutralizing and anti-S-RBD antibodies.

Time of sampling (in months)	r	P value
1	0.9	<10^−3
3	0.8	<10^−3
6	0.8	<10^−3
9	0.8	<10^−3
12	0.7	0.037

r: Spearman’s rank correlation coefficient.

Figure 1. Antibody response over time following natural infection: a and c: illustrate the median value of the log-transformed anti-S-RBD IgG levels with the interquartile range; b and c: illustrate the median value of neutralizing antibodies with the interquartile range.

Figure 2. Kinetics of anti-SARS-CoV-2 antibodies over time in reinfected participants (n = 23).

Table 3. Factors associated with reinfection: results of univariate analysis.

Variables	N	Reinfection n (%)	p-value
Sex			0.19
Male	19	4 (21.1)
Female	51	19 (37.3)
Age (years)			0.33
<40	27	7 (25.9)
≥40	43	16 (37.2)
Comorbidities			0.94
Yes	30	10 (33.3)
No	40	13 (32.5)
Symptomatic infection			1
Yes	61	20 (32.8)
No	9	3 (33.3)
Mask wearing			0.46
Always/Frequently	61	19 (31.3)
Rarely/Occasionally	9	4 (44.4)
Hand Hygiene			0.09
Always/Frequently	54	15 (27.8)
Rarely/Occasionally	16	8 (50.0)

Figure 3. Antibody response over time following natural infection among non-reinfected participants: a and c: illustrate the median value of the log-transformed anti-S-RBD IgG levels with the interquartile range; b and c: illustrate the median value of neutralizing antibodies with the interquartile range.

Figure 4. Percentage of detectable anti-spike and neutralizing antibodies over time (n = 47).

Data availability statement

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.