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Safety and Immunogenicity of SII's 10-Valent Pneumococcal Conjugate Vaccine (PCV10-SII) in Vietnamese Children Aged
Vu Tung Son1, Bui Dang The Anh1, Vu Ngoc Hoan1
1Department of Military Epidemiology, Vietnam Military Medical University (VMMU), Hanoi 100000, Vietnam.
Insights
The 10-valent pneumococcal conjugate vaccine (PCV10-SII) showed excellent safety and strong immune responses in Vietnamese children. This affordable vaccine is suitable for national immunization programs to prevent pneumococcal disease.
Area of Science:
- Pediatric Infectious Diseases
- Vaccinology
- Public Health
Background:
- Pneumococcal conjugate vaccines (PCVs) are crucial for preventing severe childhood pneumococcal disease.
- High costs of existing PCVs limit accessibility in many regions.
- The World Health Organization prequalified PCV10-SII (PNEUMOSIL) in 2019 as a cost-effective alternative.
Purpose of the Study:
- To evaluate the safety and immunogenicity of PCV10-SII in Vietnamese children.
- To assess the vaccine's performance across different age groups (6 weeks to 24 months).
Main Methods:
- An open-label, single-arm study involved 304 children aged 6 weeks to 24 months.
- Participants received two or three doses of PCV10-SII.
- Safety was monitored via adverse events, and immunogenicity assessed by IgG GMCs, OPA titers, and seroresponse rates.
Main Results:
- High completion rate (96.7%) with no serious adverse events reported.
- Mild, transient local/systemic reactions occurred.
- PCV10-SII demonstrated robust immunogenicity with seroresponse rates exceeding 90% for 9 out of 10 serotypes.
Conclusions:
- PCV10-SII exhibits a favorable safety profile and strong immunogenicity in Vietnamese children.
- The vaccine is a viable, affordable option for integration into national immunization programs for pneumococcal disease prevention.
Background:
Pneumococcal conjugate vaccines (PCVs) prevent severe disease in children, but high costs limit access. PCV10-SII (PNEUMOSIL), a 10-valent PCV prequalified by the World Health Organization (WHO) in 2019, offers a cost-effective alternative. This study assessed its safety and immunogenicity in Vietnamese children aged 6 weeks-24 months.
Methods:
An open-label, single-arm study enrolled 304 children in three age groups: 6 weeks-6 months (n = 151), >6-12 months (n = 76), and >12-24 months (n = 77). Participants received two or three doses. Safety was evaluated through immediate reactions, adverse events (AEs), serious adverse events (SAEs), and withdrawals. Immunogenicity was measured 28 days after the final dose using serotype-specific IgG geometric mean concentrations (GMCs), opsonophagocytic activity (OPA) titers, and seroresponse rates. The trial was approved by the IRB of the National Ethics Council (code: No. 75/CN-HĐĐĐ on date 4 June 2021) and was registered with ClinicalTrials.gov, NCT05140720.
Results:
Of 304 enrolled participants, 294 (96.7%) completed follow-up. No immediate adverse events or serious adverse events occurred. Unsolicited adverse events were reported in 17%, mainly respiratory, while serious adverse events occurred in 4%. Mild local/systemic reactions (e.g., injection site pain, crying) resolved without sequelae. Immunogenicity was strong, with GMCs 1.8-9.11 µg/mL, GMTs 277.8-22,342, and seroresponse rates >90% for 9 of 10 serotypes, serotype 6B demonstrated a slightly lower seroresponse rate of 88.6%.
Conclusions:
PCV10-SII demonstrated favorable safety and robust immunogenicity, supporting its inclusion in national immunization programs as an affordable option for pneumococcal disease prevention.
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