2.2.11. Randomization
INFLUENZA
On the basis of sex, age, salivary sIgA level, serum IgA level, serum IgG level, POMS2 score, COVID-19 vaccination, and influenza vaccination status, the participants were divided into two groups according to the block-randomization method. Subsequently, an independent controller assigned each group to either the LG2055 or placebo group. The controller sealed the assignment list until the designated unmasking time.