Silva Jr, Almir Ribeiro da, et al. “Neutralizing Antibodies Against the SARS-CoV-2 Omicron Variant Following Two CoronaVac Vaccinations and a Pfizer BioNTech MRNA Vaccine Booster”. Revista Do Instituto De Medicina Tropical De São Paulo, vol. 64, June 2022, p. e43, https://doi.org/10.1590/S1678-9946202264043.