A Phase I/II Study to Evaluate the Safety and Immunogenicity of GC3111B in Healthy Adults

Inclusion Criteria: * Healthy adults aged 19 to 64 years old as of the date of written consent. * Individuals with no history of vaccination with a vaccine containing diphtheria, tetanus, or pertussis antigens within the past 2 years prior to administration of the investigational product. Exclusion Criteria: * Individuals who have received a vaccine within 4 weeks prior to administration of the investigational product. * Individuals with a history of Tdap vaccination prior to administration of the investigational product. * Pregnant and breastfeeding women. * Individuals who have participated in other clinical trials involving investigational products/devices within 6 months prior to administration of the investigational product.