Sequential vaccination with Sabin-strain and wild-strain inactivated polio vaccines

An Open-labelled, Randomized, Controlled, Clinical Trial to Evaluate the Immunogenicity and Tolerability of Sequential Vaccination of Sabin Strain and Wild Strain Inactivated Poliovirus Vaccine

It will test different combinations and injection routes of inactivated polio vaccines in healthy 2-month-old infants to see if they produce strong antibody protection with good safety.

Quick facts

• Phase: Phase 4
• Study type: Interventional
• Enrollment: 480 (estimated)
• Ages: 56 Days to 84 Days
• Sex: All
• Sponsor: Sinovac Biotech Co., Ltd (Industry-sponsored)
• Locations: 3 sites (Kawit, Cavite and 2 other locations)
• Trial ID: NCT07457060 on ClinicalTrials.gov

What this trial studies

This open-label, randomized, controlled Phase IV trial will enroll 480 healthy infants aged 56–84 days and randomize them equally into four vaccination regimens: 2wIPV+1sIPV, 1wIPV+2sIPV, 3wIPV, and 3sIPV, with 28-day intervals between doses. Within each regimen, two-thirds of participants will receive injections intramuscularly and one-third subcutaneously to compare injection routes. Blood samples taken before the first vaccination and 28 days after the last vaccination will measure neutralizing antibody titers against the three poliovirus serotypes, and safety monitoring will include immediate observation, guardian diary cards for solicited and unsolicited adverse events, and collection of serious adverse events up to 28 days after the final dose. The trial is open-label and uses standardized procedures for immunogenicity and safety data collection.

Who should consider this trial

Good fit: Healthy infants aged 56–84 days with parental consent, no prior polio vaccination, available vaccination records, and mothers documented negative for HIV, syphilis, hepatitis B and C are eligible.

Not a fit: Premature infants, those with immunodeficiency or autoimmune disease, serious chronic conditions, prior polio vaccination, or known severe allergies to vaccine components are excluded and would not be expected to benefit from participation.

Why it matters

Potential benefit: If successful, the results could identify a vaccination schedule and injection route that gives infants strong poliovirus immunity with acceptable safety and inform routine immunization practice.

How similar studies have performed: Previous clinical work with both Sabin-derived and wild-strain inactivated poliovirus vaccines has shown they can generate protective antibody responses, although direct comparisons of these specific sequential regimens and injection routes are limited.

Eligibility criteria

Inclusion Criteria:

1. Infants of 2 months old (aged 56-84 days).
2. Have a parent/legal guardian who has provided written informed consent after being fully informed about the study.
3. Be able to provide the vaccination records since birth.
4. The infant's mother is tested negative for HIV, syphilis, hepatitis B, and hepatitis C during or before the infant's enrollment to this study (test results obtained during pregnancy are acceptable, if provided).

Exclusion Criteria:

1. History of any polio vaccination.
2. History of severe allergic reaction to previous vaccinations or hypersensitivity to any vaccine component.
3. Premature infants (born before week 37 of gestation).
4. History of asphyxia rescue or nervous system injury.
5. Congenital malformations, developmental disorders, clinically significant genetic defects, severe malnutrition.
6. Autoimmune diseases or immunodeficiency/immunosuppression.
7. Serious chronic diseases such as Down's syndrome, diabetes, sickle cell anemia, or neurological disorders.
8. Abnormal coagulation functions (e.g., coagulation factor deficiency, blood coagulation diseases, platelet disorders).
9. Received immunosuppressant (excluding topical or inhaled corticosteroids), cytotoxic drug, or other immunomodulatory therapies.
10. Received blood products before trial vaccine inoculation.
11. Received other study drugs within 30 days before enrollment.
12. Received live attenuated vaccines within 14 days before enrollment.
13. Received subunit or inactivated vaccines within 7 days before enrollment.
14. Acute diseases or acute exacerbations of chronic diseases within 7 days before enrollment.
15. Significant acute diseases, chronic infections, or axillary temperature ≥ 37.5°C before enrollment.
16. Any other factors deemed by the investigators as unsuitable for participation.

Where this trial is running

Kawit, Cavite and 2 other locations

• Centennial Clindev Research and Development of Medical Sciences — Kawit, Cavite, Philippines (Recruiting)
• Iloilo Doctors' Hospital — Iloilo City, Philippines (Recruiting)
• Health Index Multispecialty Clinic - Research and Development on Medical Sciences — Imus, Philippines (Recruiting)

Conditions Poliomyelitis