The purpose of this study is to evaluate safety and efficacy (immunogenicity) of a single dose of GC3111 versus Boostrix® vaccine among healthy adults in 19-64 years of age.

To evaluate immunogenicity of GC3111 as tetanus, diphtheria and acellular pertussis (Tdap) vaccine in healthy adults.

To evaluate safety of GC3111 in healthy adults.

Inclusion Criteria:

1. Healthy adults aged above 19 and under 64 at the time of screening
2. Subject without history of administrating vaccines including diphtheria, tetanus or whooping cough antigens within 2 years prior to administration of investigational drug
3. Subject who provided informed consent and assent forms

Exclusion Criteria:

1. Subject who received vaccine within 4 weeks prior to receiving study vaccine
2. Subject who received Tdap vaccine prior to receiving study vaccine
3. Subject with chronic cough history within 12 weeks before receiving study vaccine
4. Subject who is pregnant, lactating, or of child bearing potential without using an effective method of contraception or not practicing abstinence
5. Subject who participated in any other clinical study (investigational drug/equipment) within 6 months before receiving study vaccine
6. Subject with any condition that, in the opinion of the Investigator, might interfere with the ability to comply with trial procedures