SAEs and pregnancy events
A total of four (0.95%) participants reported SAEs from day 28 till month 12. All of the participants with SAEs were resolved within 5 days after the hospitalization. All the four SAEs were determined to be unrelated to vaccination (Table S5). In addition, five female participants became pregnant during the follow-up period. No adverse pregnancy outcomes or fetal abnormalities were observed during the 12-month follow-up after the booster vaccination (Table S6).