Estimated Prevalence of SARS-CoV-2 Antibodies in the Texas Pediatric Population, 2021

Background: The extent of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children and adolescents at a population level in 2021 remains unclear. Children and adolescents have been considered to play an important role in transmission regardless of presence of symptoms. The objective of this study was to estimate the prevalence of SARS-CoV-2 antibody status in children ages 5-to-19 years in a sample from the State of Texas in the presence and absence of symptoms. Methods: The TX CARES (Texas Coronavirus Antibody Response Survey) is an ongoing prospective population-based sample from the Texas general population (~29·8 million) that commenced in October 2020. For the current analysis, volunteers ages 5-to-19 years were recruited throughout the state from large pediatric healthcare systems, Federally Qualified Healthcare Centers, urban and rural pediatric and family medicine practices, health insurance providers, and a social media campaign. SARS-CoV-2 antibody status measured via the Roche Elecsys® Anti-SARS-CoV-2 Immunoassay. Prevalence of IgM, IgA, or IgG antibodies were adjusted using sampling weights and post-stratification of age and sex. We report here findings from January 1-June 1, 2021. Findings: This analysis that included 503 children ages 5-to-19 years showed 38·7% (95% CI, 34·5-43·1) of the sample was SARS-CoV-2 antibody positive in fully adjusted estimates. A total of 30·1% (95% CI, 29·4-31·5) of adults (N=6992) in the sample were antibody positive. Over half (55·8%) of those with positive antibody status were reportedly asymptomatic. Headache (25·4%), congestion/runny nose (20·8%), and fatigue (20·3%) and were the most frequently reported symptoms among those with a positive antibody result. The odds of having a positive antibody status was 37% higher in 15-to-19 year olds versus adults (OR 1·37, 95% CI, 1·03-1·83). Interpretation: These results highlight that a majority of the pediatric population remains immunologically naive to SARS-CoV-2, emphasizing the important role vaccines may play in reaching whole population herd immunity. Funding: Texas Department of State Health Services. Declaration of Interest: We declare no competing interests. Ethical Approval: All protocols were reviewed and approved by the University of Texas Health Science Center at Houston Institutional Review Board (IRB), but also deemed public health practice by the Texas Department of State Health Services IRB.