SARS-CoV-2 Antibody Prevalence in a Pediatric Cohort of Unvaccinated Children in Mérida, Yucatán, México

Abstract

Background: The prevalence of SARS-CoV-2 exposure in children during the global Covid-19 pandemic has been underestimated due to lack of testing and the relatively mild symptoms in adolescents. Understanding the exposure rates in the pediatric population is essential as children are the last to receive vaccines and can act as a source for SARS-CoV-2 mutants that may threaten vaccine escape. This study aims to quantify the prevalence of anti-SARS-CoV-2 serum antibodies in children in a major city in Mexico.Methods: We obtained socioeconomic information and blood samples from 1,005 children and tested the sera for anti-SARS-CoV-2 IgG and IgM antibodies using lateral flow immunochromatography.Findings: We found that 25·5% of children in our cohort were positive for anti-SARS-CoV-2 antibodies and there was no correlation between age and antibody prevalence. Children that lived with large families were statistically more likely to have antibodies against SARS-CoV-2. Spatial analyses identified two hotspots of high SARS-CoV-2 seroprevalence in the west of the city.Interpretation: These results indicate that a large urban population of children has been exposed to SARS-CoV-2 and that a correlating factor was the number of people within the child’s household. There is also a larger population of children that may be susceptible to future infection upon easing of social distancing measures. This is the first analysis of a large cohort of children in a Latin American country and the results may inform public health decisions and vaccination strategies.Funding Information: This work was supported by NIH grant U01AI148069 and received support from the Universidad Autónoma de Yucatán.Declaration of Interests: The authors declare no conflicts of interestEthics Approval Statement: This study capitalized on a pediatric cohort established to evaluate the epidemiological impact of indoor residual spraying on arbovirus transmission and utilized serum stored after either participant written consent or verbal assent was attained.(7) All participants agreed to have their specimens kept for future use. All procedures for participant assent/consent, blood acquisition, and serum storage were approved by the Institutional Review Boards of Emory University (IRB00108666) and the Universidad Autónoma de Yucatán (CEI-05-2020).