The immunogenicity and safety of the adsorption of cell-free diphtheria and tetanus (three-component) combined vaccine were evaluated at 2 months, 4 months and 6 months.

Inclusion Criteria:

1. Healthy infants and young children who are permanent residents aged 2 months (60-89 days), and can provide valid identification documents for the subject and their legal guardian;
2. Obtain the informed consent of the subject's legal guardian and sign the informed consent form;
3. The legal guardian of the subject can comply with the requirements of the clinical trial protocol.

Exclusion Criteria:

1. History of pertussis, diphtheria, or tetanus;
2. Contact with individuals diagnosed with pertussis or diphtheria within the past 30 days;
3. Vaccination with vaccines containing DTaP components, inactivated poliovirus vaccine, 13-valent pneumococcal polysaccharide conjugate vaccine, or Hib vaccine;
4. Premature infants (born before 37 weeks of gestation), infants with severe abnormal labor processes or a history of asphyxia rescue, or low birth weight infants (<2500g);
5. Axillary temperature >37.0°C on the day of enrollment*;
6. Severe congenital malformations or developmental disorders, genetic defects, severe malnutrition, or congenital diseases (such as Down syndrome, sickle cell anemia, congenital nervous system diseases, etc.);
7. History of epilepsy, convulsions, or seizures, history of cerebral palsy, or family history of mental illness;
8. Autoimmune diseases or immunodeficiencies (such as perianal abscesses suggesting possible immunodeficiency in infants, human immunodeficiency virus infection, lymphoma, leukemia, etc.), or parents/siblings with autoimmune diseases or immunodeficiencies;
9. Asplenia or splenic dysfunction due to any cause;
10. Clinically diagnosed coagulation disorders (such as coagulation factor deficiencies, coagulation diseases, platelet abnormalities) or obvious bruising/coagulation disorders that may contraindicate intramuscular injection;
11. History of severe allergic diseases (such as anaphylactic shock, allergic laryngeal edema, allergic purpura, thrombocytopenic purpura, local allergic necrotic reactions), history of severe allergic reactions to any vaccine (widespread urticaria, angioedema, etc.), or allergy to any known component of the test vaccine (pertussis toxoid, filamentous hemagglutinin, 69KD outer membrane protein, diphtheria toxoid, tetanus toxoid, aluminum hydroxide, sodium chloride, sodium hydroxide, etc.);
12. Vaccination with subunit or inactivated vaccines within the past 7 days; vaccination with live attenuated vaccines within the past 14 days*;
13. Receipt of immunoglobulin and/or any blood products (except hepatitis B immunoglobulin) before enrollment;
14. Receipt of any immunostimulant or immunosuppressant therapy before enrollment (continuous oral administration or infusion for ≥14 days, or topical steroid use [inhaled, nasal spray, intra-articular, eye drops, ointments, etc.] exceeding the recommended dosage in the package insert);
15. Suffering from acute illnesses within 3 days before enrollment (acute illness is defined as moderate or severe illness with or without fever)*;
16. Administration of prophylactic medications (such as antipyretic analgesics, antiallergic drugs, antidiarrheal drugs, etc.) within 3 days before enrollment*;
17. Known or suspected severe clinically diagnosed diseases (including but not limited to severe diseases of the nervous, cardiovascular, hematological and lymphatic, immune, renal, hepatic, gastrointestinal, respiratory, metabolic, and skeletal systems, as well as a history of malignant tumors);
18. Currently participating in other clinical trials or planning to participate in other trials during the study period;
19. Any other factors that, in the judgment of the researcher, make the subject unsuitable for participating in the clinical trial.