THURSDAY, Jan. 20, 2022 (HealthDay News) A fourth dose of an mRNA-based anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine may increase antispike immunoglobulin (Ig)G titers in kidney transplant recipients, according to a research letter published online Jan. 11 in the Annals of Internal Medicine. Sophie Caillard, M.D., Ph.D., from the University Hospitals of