Enrolled participants will have a survey about demographic information, history of previous suspected/confirmed Covid-19 infection or exposed to SARS-CoV-2, Covid-19 vaccination status. For participants aged less than 12 months, participants' mothers' status of Covid-19 vaccination and/or previous infection will be recorded. Participants will then complete serologic testing for SARS-CoV-2 IgG antibodies using residual plasma specimens collected/stored for routine laboratory tests on the date of enrollment. The study will characterize the prevalence of antibody positivity in this population and assess whether there is a correlation between demographic characteristics and antibodies levels.
