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Published on: September 7, 2017
Safety, Immunogenicity and Lot-to-Lot Consistency of Sabin-Strain Inactivated Poliovirus Vaccine in 2-Month-Old
Yan Zheng1, Zhifang Ying2, Yanxiang Zou1
1Vaccine Clinical Research Center, Yunnan Provincial Center for Disease Control and Prevention, Kunming 650034, China.
Insights
The Sabin-strain inactivated poliovirus vaccine (sIPV) demonstrated strong and consistent immune responses in infants. Safety and tolerability were comparable to the control inactivated poliovirus vaccine (IPV).
Area of Science:
- Vaccinology
- Pediatric Infectious Diseases
- Clinical Trials
Background:
- Sabin-strain inactivated poliovirus vaccine (sIPV) is crucial for global polio eradication efforts.
- Phase III clinical trials are essential for evaluating vaccine efficacy and safety in target populations.
- Assessing lot-to-lot consistency is vital for ensuring vaccine quality and reliable protection.
Purpose of the Study:
- To evaluate the safety and immunogenicity of a Sabin-strain inactivated poliovirus vaccine (sIPV).
- To assess the lot-to-lot consistency of the sIPV in 2-month-old infants.
- To compare the sIPV's performance against a control inactivated poliovirus vaccine (IPV).
Main Methods:
- Phase III, randomized, double-blind, positive-controlled trial involving 1300 infants.
- Infants received one of three sIPV lots or control IPV at 2, 3, and 4 months of age.
- Immunogenicity assessed via seroconversion rates and geometric mean titers (GMTs); safety monitored through adverse event recording.
Main Results:
- High seroconversion rates (92.88%-99.67%) observed across all three poliovirus types for sIPV lots.
- sIPV lots demonstrated immunological equivalence, meeting predefined criteria for GMT ratios.
- Pooled sIPV group showed non-inferior seroconversion rates compared to the IPV group, with similar mild-to-moderate adverse reactions.
Conclusions:
- Three consecutive lots of sIPV exhibited robust and consistent immunogenicity.
- The sIPV demonstrated acceptable safety and tolerability profiles, comparable to the IPV.
- The sIPV is a promising candidate for continued use in poliomyelitis eradication programs.
Background:
The Sabin-strain-based inactivated poliovirus vaccine (sIPV) plays an important role in poliomyelitis eradication in developing countries. As part of the phase III clinical development program, this study aimed to evaluate the safety, immunogenicity and lot-to-lot consistency of the sIPV in 2-month-old infants.
Method:
We conducted a phase III, randomized, double-blind, positive-controlled trial in which 1300 healthy infants were randomly assigned to four groups in a 1:1:1:1 ratio to receive one of the three lots of the sIPV or the control IPV at 2, 3 and 4 months of age. Serum samples were collected before the first dose and 30 days after the third dose of vaccination to assess the immunogenicity. Solicited local and systemic reactions were recorded within 7 days and unsolicited adverse events within 30 days after each vaccination.
Results:
Of the 1300 randomized infants, 1190 infants completed the study and were included in the per-protocol population. The seroconversion rates in the three lots of the sIPV were 95.67%, 97.03% and 95.59%, respectively, for type 1; 94.33%, 93.73% and 92.88%, respectively, for type 2; and 98.67%, 99.67% and 99.32%, respectively, for type 3. The ratios of GMTs for poliovirus types 1, 2 and 3 of each pair of lots were all between 0.67 and 1.50, therefore meeting the predefined immunological equivalence criteria. For the seroconversion rate of poliovirus types 1, 2 and 3, the pooled sIPV group was non-inferior to the IPV group. The incidence of solicited and unsolicited adverse reactions (ARs) was similar in the pooled sIPV lots and the IPV group, and most of them were mild to moderate in severity. Non-vaccine-related serious adverse events (SAEs) were reported.
Conclusions:
Three consecutive lots of sIPV demonstrated robust and consistent immunogenicity. The safety and tolerability of the sIPV was acceptable and similar to that of the IPV.
