• Basic immune stage:

‣ 3-month-old infants who can provide valid identification documents;

⁃ Infants should be born following a 37-42 weeks of pregnancy and have a birth weight that meets the standard (2500g ≤ body weight ≤ 4500g);

⁃ The legal guardian of the subject voluntarily agrees to their child's participation in the trial and signs a written informed consent form;

⁃ The legal guardian of the subject has the ability to understand the trial procedure and participate in all planned follow-up visits;

⁃ Has not received a vaccine containing the active ingredients of pertussis, diphtheria, tetanus combined vaccine;

⁃ Active control group 2 has not been vaccinated with any vaccine containing the active ingredients of poliomyelitis vaccine or haemophilus influenzae vaccine;

• Enhanced immunity stage:

‣ Infants and young children aged 18-24 months who have been enrolled in this clinical trial at the age of 3 months;

⁃ Basic immunization has been completed in this clinical trial;

⁃ According to the researcher's opinion, the subjects and their legal guardians are able to comply with the requirements of the clinical trial protocol.