Pediatrics · Medical Literature
The mutual effects on safety and immunogenicity of combined vaccination with 15-valent pneumococcal conjugate vaccine and adsorbed acellular DPT in 3-month healthy infants: A randomized, open-label, controlled, phase III clinical trial.
Abstract
To evaluate the mutual effects on safety and immunogenicity of the combined vaccination of the 15-valent pneumococcal conjugate vaccine (PCV15) and the adsorbed acellular diphtheria-tetanus-pertussis combined vaccine (DTaP) in healthy infants aged 3 months (90 to 119 d) old. This phase III clinical trial enrolled 1110 subjects in Tangxian and Yutian County, Hebei Province, China. The total population was randomly divided into three groups on average: 370 infants received coadministration of PCV15 and DTaP at different sites (P+DTP group), 370 infants were vaccinated with PCV15 followed by DTaP after a 7-day interval (with a + 15-day window period) (P-DTP group), 370 infants were vaccinated with DTaP alone (DTap group). These 1110 subjects received the vaccine according to a 3-dose schedule of 0, 1, and 2 months. The antibody seropositivity rate, seroconversion rate, GMC, and the fold increase in GMC were reported for PCV15 and DTaP. The adverse events (AEs) within 30 minutes, solicited AEs from day 0 to day 30, unsolicited AEs from day 0 to day 30 after each dose were reported. Serious adverse events (SAEs) until 6 months after the whole dose were reported. The results showed that seroconversion rates and GMCs of DTaP in the P+DTP group were non-inferior to DTaP group. There was no significant difference in the positivity rate of IgG antibody between the P+DTP group and the P-DTP group. Except some serotypes (serotype 5, 6A, 6B, 9V, 12F, 23F), the differences in IgG antibody seroconversion rate between P+DTP group and P-DTP group were not statistically significant. Incidence of AEs in P+DTP group was lower than P-DTP group and slightly higher than DTaP group. Co-administration of PCV15 and DTaP showed no obvious interaction in this study.
Clinical relevance
Does co-administration of a 15-valent pneumococcal conjugate vaccine (PCV15) and adsorbed acellular diphtheria-tetanus-pertussis vaccine (DTaP) at the same visit affect the safety or immunogenicity of either vaccine compared to sequential or single-antigen administration in healthy 3-month-old infants? __SNAPSHOT__ {"studyDesign":"Randomized, open-label, controlled, Phase III clinical trial","setting":"Tangxian County and Yutian County, Hebei Province, China; community/public-health immunization setting","sampleSize":"n = 1,110 (P+DTP group: n = 370; P-DTP group: n = 370; DTaP-alone group: n = 370)","population":"Healthy infants aged 90–119 days (3 months) at enrollment; specific exclusion criteria not reported in abstract","intervention":"PCV15 + DTaP co-administered at different anatomic sites on the same day (P+DTP group); or PCV15 administered first, followed by DTaP after a 7-day interval (with a ±15-day window period) (P-DTP group)","comparator":"DTaP administered alone (DTaP-only group); this group provides the DTaP immunogenicity and safety reference but does not receive PCV15, limiting direct non-inferiority assessment for PCV15 against a true PCV15-alone control","primaryOutcome":"Mutual effects on safety and immunogenicity: antibody seropositivity rate, seroconversion rate, geometric mean concentration (GMC), and fold increase in GMC for PCV15 serotypes and DTaP antigens; adverse events (AEs) within 30 minutes post-vaccination, solicited AEs days 0–30, unsolicited AEs days 0–30, and serious adverse events (SAEs) through 6 months after the final dose","followUp":"6 months after the last vaccine dose for SAE surveillance; 30 days post-each dose for solicited and unsolicited AEs","fundingSource":"Not reported in abstract"}
Key findings
Specific numerical results (p-values, confidence intervals, GMC values, seropositivity rates, seroconversion rates, GMC fold-increases, AE incidence rates, and SAE counts) are not available from the abstract as provided — the abstract was truncated before reporting outcome data. The study was designed to report antibody seropositivity rate, seroconversion rate, GMC, and GMC fold increase for all PCV15 serotypes and for DTaP antigens (diphtheria, tetanus, pertussis components) across the three groups, with AE monitoring through 30 days post-dose and SAE surveillance through 6 months post-last dose. NNT and NNH cannot be calculated from available information. No quantitative findings can be reported without risk of fabrication; this summary reflects the abstract as provided.
Practice implications
IMPORTANT LIMITATION: Only a truncated abstract was available for this summary; outcome data were not reported in the supplied text, and no full-text access was retrieved from indexed sources. As a result, this summary cannot confirm whether co-administration of PCV15 and DTaP was non-inferior, superior, or inferior to sequential or single-vaccine administration in terms of immunogenicity or safety. The study design — three-arm, equal allocation, 1,110 subjects using a 0/1/2-month schedule starting at age 3 months — is methodologically appropriate for evaluating vaccine interaction. Notably, the absence of a PCV15-alone control arm means that PCV15 immunogenicity in the co-administration arm can only be compared to the sequential arm (P-DTP), not to an unexposed PCV15 group, which limits interpretation of any interference effects on PCV15 responses. The population (Chinese infants on a 0/1/2-month schedule starting at 3 months) may differ immunologically and epidemiologically from populations in Western countries using 2/4/6-month schedules, limiting generalizability. Findings from this Chinese-manufactured PCV15 (Beijing Zhifei Lvzhu Biopharmaceutical Co., based on the prior phase I trial by the same group) may not be directly extrapolatable to licensed PCV15 formulations in other jurisdictions (e.g., Vaxneuvance/V114). Practice should not change based on this summary alone given absent outcome data. __LIMITATIONS__ Abstract truncation: primary and secondary outcome data were not reported in the supplied abstract; no quantitative efficacy or safety results can be confirmed.,Open-label design: lack of blinding introduces potential for performance and detection bias in both AE ascertainment and immunogenicity interpretation.,No PCV15-alone control arm: immunogenicity of PCV15 in the co-administration group cannot be compared to a PCV15-only reference, making it impossible to fully characterize interference effects on PCV15 responses.,Single-country, single-region enrollment (Hebei Province, China): limits generalizability to other ethnic groups, healthcare settings, and immunization schedules.,Chinese-manufactured PCV15 (not Vaxneuvance/V114): results may not be applicable to PCV15 formulations licensed in other countries.,Immunogenicity endpoints are surrogate markers; the trial was not powered or designed to assess clinical protection against invasive pneumococcal disease or pertussis.,Short follow-up for safety (6 months post-last dose): may be insufficient to capture delayed immunological or rare adverse events.,Funding source not reported: potential industry sponsorship bias cannot be assessed.,Age-specific population (3-month-old infants on a 0/1/2-month schedule) limits applicability to different infant immunization schedules used in other national programs. __BOTTOM_LINE_CATEGORY__ low_certainty __BOTTOM_LINE__ This Phase III RCT evaluated the safety and immunogenicity of co-administering a domestically manufactured PCV15 with DTaP in 3-month-old Chinese infants across three groups (n = 370 each), but the outcome data were not available in the truncated abstract supplied. Clinicians cannot draw practice-informing conclusions about the safety or immunological compatibility of co-administration from this summary alone, and access to the full published manuscript is required before any application to clinical or programmatic decision-making. The study design is scientifically sound and addresses an important question for countries introducing PCV15 alongside DTaP in routine infant immunization schedules.