Abstract

Background: The rapid and deadly spread of the novel coronavirus in Mumbai necessitated population wide seroprevalence analysis including the paediatric subset. This would assist in healthcare interventions and shaping of public policies amidst the raging pandemic. Methods: This observational, cross-sectional study was conducted across twenty-four wards of Mumbai using left over blood samples from individuals younger than 18 years from public and private laboratories, during the delta wave. Chemiluminescence assay (CLIA) was performed to detect anti-nucleocapsid IgG (anti-N IgG); anti-N IgG negative samples were subsequently tested for anti-spike protein S1-receptor binding domain IgG (anti-S1RBD IgG). The primary outcome of presence of either anti-N IgG or anti-S1 RBD IgG, was reported using Chi–squared test of equal proportions to determine the strength of association. The 95% confidence interval of the seroprevalence was calculated using Clopper Pearson exact method. Results: 51.5% of the 2172 samples tested were seropositive for either anti-N IgG or anti-S1 RBD IgG antibodies. Samples collected from public facilities showed higher seropositivity than those from private facilities. There was no significant difference in seropositivity based on gender or age alone. Conclusion: The results of this study suggest that half of the children living in Mumbai had antibodies to SARS-CoV-2 during the Delta wave. The study highlights the involvement of the paediatric population in community transmission despite school closures and lockdown measures. With the evolution of SARS-CoV-2 into Omicron, it is safe to assume that the virulence of SARS-CoV-2 has the potential to alter. Therefore, the physical, mental and social well-being of children must be weighed into every public health policy moving forward.

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