2.2. Study Outcomes
diabetes, psychiatric, angina, cardiovascular diseases
MALIGNANT TUMORS, DIABETES, MYOCARDIAL INFARCTION, STROKE, CARDIOVASCULAR DISEASES
The inclusion criteria for this study included the following: adults aged 30 years or older, participants who had taken red ginseng for at least one month within the last month prior to vaccination (KRG group), and individuals who had not taken red ginseng for two or more months before vaccination (control group). Subjects were excluded if they met any of the following criteria: patients being treated for cardiovascular diseases such as angina, myocardial infarction, stroke, uncontrolled diabetes, undergoing treatment for malignant tumors, taking antidepressants, antipsychotics, other psychiatric medications, and consuming functional foods including multivitamins. All subjects received the COVID-19 vaccine three times, and they visited the hospital five times to measure vaccine-induced antibodies to the spike protein receptor-binding domain (anti-S-Ab) and nucleocapsid (anti-NC) SARS-CoV-2 protein and anti-N-Ab. We checked anti-NC antibodies to evaluate whether patients were infected with COVID-19. No anti-NC antibodies were detected during or after vaccination. The second dose of the vaccine was administered four weeks after the first dose. We evaluated antibodies just before the second dose (baseline), 2, 4, and 12 weeks after the second dose, and 4 weeks after the third dose, independent of the type of vaccine. We first measured serum antibody levels and investigated possible changes at each time point. The change after 4 weeks compared with baseline was considered as the primary endpoint to calculate statistical power. We further compared changes in antibody levels in the KRG group vs. the control group.