Fig. 3: Children and adults produce antibodies with equal neutralizing potential and their antibodies offer the same protection against Variants of Concern.
From: Robust and durable serological response following pediatric SARS-CoV-2 infection
a Box and whisker plot showing that antibodies produced by children (orange, n = 118) have a significantly higher inhibition of ACE2 binding than those produced by adults (blue, n = 267, p = 4.37 x 10−13) at T1 and T2 (p = 0.02, child n = 59, adult n = 106) as determined by the sVNT assay. Boxes represent the median, 25th and 75th percentiles, while whiskers show the largest and smallest non-outlier values. Outliers were identified using upper/lower quartile ±1.5 times IQR. Statistical significance was calculated using Mann–Whitney-U (two-sided) with *** indicating a p value < 0.001, * indicating a p value < 0.05, and ns indicating a non-significant p value > 0.05. To determine whether this was due to the higher titers in children, SARS-CoV-2 S1 humoral response was determined using MULTICOV-AB for T1 and plotted against the results of the sVNT assay (b). Spearman’s rank was calculated to measure the ordinal association between them, confirming that the increase in neutralization is due to higher titers. Protection against the Alpha (c) and Beta (d) VOCs was determined by MULTICOV-AB and plotted as a linear regression against the antibody binding response to the wild-type (wt) receptor binding domain (RBD), with Spearman’s rank calculated to measure the ordinal association. There was no difference in antibody response between children (n = 166, T1 samples only) and adults (n = 381, T1 samples only) for either variant. (e) Box and whisker plot showing reduced neutralization responses in both adults (blue, n = 142, p = 4.38 x 10−3) and children (orange, n = 83, p = 6.36 x 10−3) against Delta VOC as compared to WT as determined by a pseudotype virus assay (VNT). Boxes represent the median, 25th and 75th percentiles, while whiskers show the largest and smallest non-outlier values. Outliers were identified using upper/lower quartile ±1.5 times IQR. Statistical significance was calculated using Mann–Whitney-U (two-sided) with ** indicating a p value < 0·01 and ns indicating a non-significant value >0.05. Titers are given as serum dilution factor resulting in 50% pseudovirus neutralization (PVNT50). The dashed line represents the lower limit of detection. f Linear regression comparing wild-type (VNTwt) and delta (VNTdelta) neutralization responses with Spearman’s rank calculated to measure the ordinal association. ACE2 angiotensin-converting enzyme 2, MFI Median Fluorescence Intensity, (s)VNT (surrogate) Virus Neutralization Test, wt wild type.
