Table 1.

Comparisons of the SARS-CoV-2 S1-specific antibody levels in nasal epithelial lining fluid (NELF) between symptomatic paediatric and adult patients with mild disease.

Nasal Epithelial Lining Fluid (NELF)
Days Post Diagnosis	IgA	0–4	5–9	12–16	19–23	26–30	83–99	169–197
Symptomatic paediatric patients	n	17	19	19	18	17	16	15
	Median ± IQR	0.7 ± 0.13	1.5 ± 3.1	8.2 ± 12.7	7.7 ± 8.8	8.3 ± 10.7	3.1 ± 5.6	1.8 ± 2.4
	%	35	63	95	89	94	88	53
Adult patients with mild disease	n	13	17	18	15	14	10	8
	Median ± IQR	0.3 ± 1.7	1.1 ± 4.0	3.4 ± 5.5	4.7 ± 6.7	5.9 ± 8.5	1.1 ± 4.2	1.7 ± 3.9
	%	31	47	89	93	93	50	63
Mann-Whitney test between groups		0.3203	0.2676	0.1701	0.1004	0.2619	0.1089	0.8746
Fisher’s Exact test between groups		ns	0.5027	0.6039	ns	ns	0.0687	ns
	IgG
Symptomatic paediatric patients	n	16	18	18	18	17	16	15
	Median ± IQR	0.1 ± 0.0	0.1 ± 0.1	0.2 ± 0.2	0.5 ± 1.2	0.6 ± 1.0	0.4 ± 0.8	0.2 ± 0.3
	%	0	0	0	28	24	19	7
Adult with mild disease	n	10	10	10	10	9	8	7
	Median ± IQR	0.1 ± 0.1	0.1 ± 0.1	0.1 ± 1.0	0.2 ± 0.2	0.6 ± 0.8	0.1 ± 0.3	0.1 ± 0.1
	%	0	0	20	0	11	0	0
Mann-Whitney test between groups		0.8664	0.1632	0.2400	0.0821	0.6723	0.0034	0.0085
Fisher’s Exact test between groups		ns	ns	0.1190	0.1282	0.6279	0.5257	ns