Study design
SECONDARY, SARS-COV-2 INFECTION
The study was a single-center, randomized, triple-blinded, placebo-controlled intervention study with a parallel design and two study arms. The primary outcome parameter was the effect of probiotic supplementation on serum anti-spike (S) IgG levels following SARS-CoV-2 infection. The secondary outcomes included the serum levels of other anti-SARS-CoV-2 specific antibodies as well as the severity and duration of COVID-19 symptoms. COVID-19 vaccine-induced antibody responses were included as exploratory outcome measures.After giving their informed consent and completing the screening procedures, participants eligible for the study were randomized into the two study arms (placebo, active treatment) prior to undergoing a baseline visit before the start of the intervention period (Study design.