This is a phase I, open-label clinical study to evaluate the ability of UB-612 vaccine to boost immunity of subjects who previously received two doses of AstraZeneca COVID-19 vaccine (ChAdOx1-S) with an 8-16 week interval between first and second doses.~This study will enroll approximately 30 subjects aged 20 to 55 years. The previous COVID-19 vaccine series will have been completed at least six months before study enrollment. Both sexes should be evenly distributed in subjects.~Subjects will be enrolled to receive one dose of 100 μg UB-612 vaccine at Day 1. The subjects will come to the clinics at Visit 1 (screening, Day -28 to -1), Visit 2 (Day 1, vaccination), Visit 3 (Day 15, 14 days after vaccination), Visit 4 (Day 29, 28 days after vaccination), Visit 5 (Day 169, 6 months after vaccination) and will receive phone calls at 7 days after vaccination for safety check.
This is a study to evaluate the ability of UB-612 vaccine to boost immunity of subjects who previously received two doses of AstraZeneca COVID-19 vaccine (ChAdOx1-S) with an 8-16 week interval between first and second doses.