Estimated pediatric SARS-CoV-2 seroprevalence in Arkansas over the first year of the COVID-19 pandemic

Boehme, K. W.; Kennedy, J. L.; Snowden, J.; Owens, S. M.; Kouassi, M.; Mann, R. L.; Paredes, A.; Putt, C.; James, L.; Jin, J.; Du, R.; Kirkpatrick, C. R.; Modi, Z.; Caid, K.; Zohoori, N.; Kothari, A.; Boyanton, B.; Forrest, J. C.

ABSTRACT Importance: As vaccines for children under the age of 12 are not yet approved, determining the SARS-CoV-2 infection rate in children is important for decisions about protective measures to be taken during the 2021-2022 school year. Objective: To estimate the prevalence of SARS-CoV-2 antibodies in residual serum samples from pediatric patients in the state of Arkansas over the first year of the COVID-19 pandemic as an indicator of SARS-CoV-2 infection rates in children. Design: The study is a survey of SARS-CoV-2 seropositivity in children in Arkansas over the first year of the COVID-19 pandemic. From April 2020 through April 2021, remnant serum samples were collected across five time periods (waves): April 2-May 6, June 6-August 10, September 8-October 17, November 7-December 17, 2020 and April 5-April 28, 2021. Setting: The multi-site survey collected remnant serum samples from four clinics across the state of Arkansas: Arkansas Children's Hospital (ACH, Little Rock, AR), Arkansas Children's Northwest (Springdale, AR), and UAMS Family Medical Centers (Ft. Smith, AR and Pine Bluff, AR) Participants: The study population consisted of 2400 convenience serum samples from children ages 1-18 who visited hospitals or regional clinics in Arkansas for non-COVID-19-related reasons. Exposures: Infection with SARS-CoV-2. Main outcomes and measures: The presence of IgM and/or IgG antibodies to the SARS-CoV-2 Spike and Nucleoprotein were determined using a two-step enzyme-linked immunosorbent assay. Seroprevalence was estimated by demographic group, including age (1-4, 5-9, 10-14, and 15-18 years), sex, race/ethnicity (white, black, Hispanic), metropolitan status, SARS-CoV-2 PCR testing, and co-morbidities (respiratory virus infection within 6 months, asthma, hypertension, obesity, diabetes, autoimmune disease). Association with SARS-CoV-2 antibody reactivity was determined by demographic group. Results: The overall SARS-CoV-2 seroprevalence rose from 7.9% in Wave 1 (95%CI, 4.9-10.9%) to 25.8% in Wave 5 (95% CI, 22.2-29.3%), as did the age- and sex-standardized seroprevalence rate which ranged from 8.6% in Wave 1 (95%CI, 5.1-11.1%) to 24.2% in Wave 5 (95% CI, 20.1-28.2%). Hispanic children had a significantly higher risk of testing positive for SARS-CoV-2 antibodies than non-Hispanic white children in Wave 3 (RR 2.82, 95% CI, 1.81-4.38), Wave 4 (RR 1.76, 95% CI, 1.03-3.00), and Wave 5 (RR 2.37, 95% CI, 1.69-3.33) Similarly, black children also showed a significantly higher risk of testing positive for SARS-CoV-2 antibodies than white children in Wave 3 (RR 1.71, 95% CI, 1.03-2.84) and Wave 5 (RR 1.59, 95% CI, 1.08-2.34). Conclusions and relevance: The percentage of Arkansas children with SARS-CoV-2-specific antibodies increased from April 2020 to April 2021. These data indicate that many more children have been infected with SARS-CoV-2 than indicated by diagnostic testing. With the emergence of SARS-CoV-2 variants, recognition of long-term effects of SARS-CoV-2 even after mild or asymptomatic infections, and the lack of an authorized pediatric SARS-CoV-2 vaccine, these results highlight the importance of including children in SARS-CoV-2 public health, clinical care, and research strategies. These findings are important for state and local officials as they consider measures to limit SARS-CoV-2 spread in schools and daycares for the 2021-2022 school year.