Home›Pediatrics› PCV10 vs PCV13 in Infants: Serotype-Specific Seroinfection Risk Differences
PCV10 vs PCV13 in Infants: Serotype-Specific Seroinfection Risk DifferencesTrial shows different protection levels for two pneumococcal vaccines
Human vaccines & immunotherapeuticsPublished September 17, 2026Study authors: Akeju Oluwasefunmi, Feng Shuo, Clarke Ed, Bashorun Adedapo O, Adigweme Ikechukwu, Pidduck Nicola, Vo…PubMed ↗DOI ↗Editorial oversight: Dr. Sofia Müller, MD · Lifespan & Whole-Person Care
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Key Takeaway
PCV10 lowered serotype 14 seroinfection risk but increased 6A and 6B risk versus PCV13 in infants.
In a randomized trial of 716 infants, researchers compared the 10-valent pneumococcal conjugate vaccine (PCV10) with the 13-valent vaccine (PCV13) for their impact on seroinfection risk. Seroinfection served as the primary outcome, measured four weeks after primary vaccination and at booster vaccination.
For serotype 14, PCV10 was associated with a 65% lower risk of seroinfection compared with PCV13 (RR 0.35; 95% CI 0.22, 0.57). In contrast, PCV10 was linked to a 2.27-fold higher risk for serotype 6A (RR 2.27; 95% CI 1.40, 3.68) and a 2.91-fold higher risk for serotype 6B (RR 2.91; 95% CI 1.84, 4.60). No difference was found for shared serotypes.
Secondary outcomes included serotype-specific IgG levels, though these results were not detailed in the abstract. Safety outcomes such as adverse events, serious adverse events, and discontinuations were not reported.
The study's main limitation is that seroinfection is a surrogate marker for colonization, subclinical infection, or disease, not a direct measure of clinical illness. Therefore, the observed differences in seroinfection risk should not be overinterpreted as differences in clinical disease.
Funding was provided by the Gates Foundation (INV-056261_2023). The findings suggest that PCV10 may offer better coverage in settings with high prevalence of serotype 14 disease, but its higher risk for 6A and 6B seroinfection warrants consideration in cost-effectiveness analyses and vaccine policy decisions.
How this fits prior evidence
How this fits prior evidence: This finding extends the evidence regarding pneumococcal disease and the protective effects of pneumococcal conjugate vaccines in children. It specifically addresses the differences in serotype-specific coverage between PCV10 and PCV13. While previous coverage noted that PCVs reduce antimicrobial resistance through direct serotype suppression, this study highlights specific serotype risks (6A and 6B) associated with the PCV10 formulation.
Protecting infants from pneumococcal disease is a major goal for public health. However, not all vaccines provide the same level of protection against every strain of the bacteria. A trial involving 716 infants compared two types of vaccines: PCV10 and PCV13.
The results showed that PCV10 was much more effective at reducing the risk of infection for serotype 14. However, the study found that infants who received PCV10 had a higher risk of infection for serotypes 6A and 6B compared to those who received PCV13. For other shared serotypes, the two vaccines performed similarly.
It is important to note that the study measured seroinfection, which is a marker for how the body reacts to the bacteria, rather than clinical illness. Because different regions have different amounts of specific strains, the best vaccine choice may depend on which strains are most common in a specific area.
What this means for you:
Different pneumococcal vaccines provide different levels of protection against specific strains of the bacteria.
Common questions
How do the two vaccines compare for different strains?
The trial found that PCV10 showed a 65% lower risk of infection for serotype 14 compared to PCV13. However, PCV10 showed a 2.27-fold higher risk for serotype 6A and a 2.91-fold higher risk for serotype 6B when compared to PCV13.
What is seroinfection?
Seroinfection is used as a way to measure how the body responds to the bacteria. It can be a sign of colonization, a minor infection, or a more serious disease. Because it is a proxy, it does not directly measure the severity of clinical illness.
Which vaccine is better for infants?
The best vaccine depends on which strains are most common in a specific area. For example, PCV10 may offer better coverage in places where serotypes 6A and 19A are common. You should talk to a doctor to determine the best option for your child.
BACKGROUND: A new 10-valent pneumococcal conjugate vaccine (PCV10) was prequalified by WHO in 2019 for children based on non-inferiority of immunogenicity to PCV13 and PCV10. However, the efficacy of PCV10 against pneumococcal carriage or disease has not been compared with other PCVs. We compared the risk of seroinfection in PCV10 with PCV10 and PCV13-vaccinated infants.
METHODS: Data were available for 716 infants from two randomised trials comparing the immunogenicity of PCV10 with PCV13 and PCV10. Serotype-specific IgG levels were measured from serum samples collected at four weeks after the primary vaccination series and at the time of booster vaccination. We defined seroinfection as any increase in serotype-specific IgG between post-primary vaccination and the booster dose, indicating likely colonisation, subclinical infection, or disease. We compared the relative risk (RR) of seroinfection between PCVs.
RESULTS: There was no difference in the risk of seroinfection between PCV10 and PCV10 for the shared serotypes, but PCV10 showed better protection against 6A and 19A, not included in PCV10. Compared with PCV13, the risk of seroinfection was 65% lower in PCV10 for serotype 14 (RR = 0.35, 95% CI: 0.22, 0.57), 2.27-fold (95% CI: 1.40, 3.68) and 2.91-fold (95% CI: 1.84, 4.60) higher for 6A and 6B seroinfection, and similar for the remaining serotypes.
CONCLUSION: PCV10 demonstrated comparable seroefficacy as PCV10 against colonisation by serotypes common to both and may offer better coverage in countries with high prevalence of 6A and 19A disease. The serotype-specific differences in seroefficacy between PCV10 and PCV13 should be considered when evaluating cost effectiveness. Funding Gates Foundation (INV-056261_2023).
