Safety and Immune Response Study of DTaP-IPVHib Pentavalent Vaccine in Chinese Infants Vaccinated at 2 Months

What this Trial Is About

This research aims to evaluate the immune response persistence and rates of pertussis breakthrough infections between 19 and 36 months of age in healthy infants in China who received two different vaccination schedules of the DTaP-IPVHib Pentavalent Vaccine starting at 2 months old. The study is a randomized, open clinical trial with two groups differing in the timing of vaccine doses to optimize immunization strategies. Participants receive the Pentaxim vaccine, a combination vaccine including acellular DPT, inactivated polio, and Haemophilus influenzae type b components. The intervention group gets doses at 2, 4, 6, and 18 months, while the control group receives doses at 2, 3, 4, and 18 months. Immunogenicity and safety are assessed before and after the initial three doses and after the booster at 18 months. Additionally, pathogen surveillance occurs with frequent follow-ups and sample collections. During the study, participants undergo visits for sample collection and questionnaires from 2 to 19 months, followed by twice-weekly phone calls to monitor acute respiratory infections, with further testing if infections are detected. Blood and throat samples are taken at 30 and 36 months to monitor vaccine immunity and respiratory pathogens. Researchers measure antibody levels against pertussis, diphtheria, tetanus, Hib, and polio at these timepoints to evaluate immune persistence, alongside monitoring pertussis infection rates.

Safety and Immunogenicity of DTaP-IPV/Hib Pentavalent Vaccine in Chinese 2-month-old Infants