Immunogenicity and safety of Sabin-strain inactivated poliovirus vaccine in infants: a systematic review and meta-analysis.

BACKGROUND

Poliomyelitis remains a threat to children under five despite global vaccination efforts. The Sabin-strain inactivated poliovirus vaccine (sIPV) has emerged as a safer alternative to conventional Salk-strain IPV (cIPV) due to lower biosafety requirements. This systematic review and meta-analysis evaluated the immunogenicity and safety of sIPV compared with cIPV in healthy infants completing the primary IPV series.

METHODS

PubMed, Embase, Scopus, and Cochrane Library were searched for RCTs. Outcomes included seroconversion rates, seroprotection rates, geometric mean titers (GMTs), and adverse events. Data were pooled using random-effects models, and evidence certainty was assessed using RoB 2.0 and GRADE.

RESULTS

Seven RCTs with 4646 infants were included. Seroconversion rates were comparable: PV1 100% (RR 1.00, 95% CI 1.00-1.01), PV2 102% (RR 1.02, 95% CI 0.98-1.07), PV3 100% (RR 1.00, 95% CI 0.99-1.01). GMTs were higher for sIPV after PV1 (MD 1.50, 95% CI 0.98-2.02) and PV2 (MD 0.52, 95% CI 0.06-0.98). Local adverse events were similar (OR 1.27, 95% CI 0.95-1.71), while systemic adverse events were higher with cIPV (OR 1.36, 95% CI 1.15-1.60). Fever (OR 1.50, 95% CI 1.20-1.87) and allergic reactions (OR 2.19, 95% CI 1.02-4.69) were slightly more frequent with sIPV.

CONCLUSIONS

sIPV provides immunogenicity comparable to cIPV with an acceptable safety profile in infants. Its lower biosafety requirements support its use in global polio eradication programs.