evidence: Uversky, V.N.; Redwan, E.M.; Makis, W.; Rubio-Casillas, A. IgG4 Antibodies Induced by Repeated Vaccination May Generate Immune Tolerance to the SARS-CoV-2 Spike Protein. Vaccines 2023, 11, 991. https://doi.org/10.3390/vaccines11050991 Uversky VN, Redwan EM, Makis W, Rubio-Casillas A. IgG4 Antibodies Induced by Repeated Vaccination May Generate Immune Tolerance to the SARS-CoV-2 Spike Protein. 2023; 11(5):991. https://doi.org/10.3390/vaccines11050991 Chicago/Turabian StyleUversky, Vladimir N., Elrashdy M. Redwan, William Makis, and Alberto Rubio-Casillas. 2023. "IgG4 Antibodies Induced by Repeated Vaccination May Generate Immune Tolerance to the SARS-CoV-2 Spike Protein" Vaccines 11, no. 5: 991. https://doi.org/10.3390/vaccines11050991