Abstract

Background By July 14, 2021, 81.3 % of adults (aged >= 18 years) in Chile had received a first SARS-CoV-2 vaccine and 72.3% had received a second SARS-CoV-2 vaccine, with the majority of people given Sinovac's inactivated CoronaVac vaccine (75.3% of vaccines dispensed) or Pfizer-BioNTech's mRNA BNT162b2 vaccine (20.9% of vaccines dispensed). Due to the absence of simultaneous real-world data for these vaccines, we aimed to compare SARS-CoV-2 IgG positivity between vaccines using a dynamic national monitoring strategy.