Trial of a supplemental dose of four poliovirus vaccines

Area of Science:

• Immunology
• Vaccinology
• Public Health

Background:

• Oral poliovirus vaccine (OPV) shows lower immunogenicity, especially for type 3, in infants from developing countries compared to industrialized nations.
• A multicenter trial was conducted in Oman to assess responses to supplemental poliovirus vaccine doses.
• Infants had previously received five doses of OPV before the study intervention.

Purpose of the Study:

• To evaluate the immunogenicity of different poliovirus vaccine formulations as a supplemental dose.
• To compare the immune response to inactivated poliovirus vaccine (IPV) versus oral poliovirus vaccine (OPV) formulations, including monovalent type 3 OPV.

Main Methods:

• 1025 infants were enrolled at nine months of age and randomly assigned to receive either IPV (subcutaneous), trivalent OPV (US or European), or monovalent type 3 OPV.
• Serum samples were collected at enrollment, 7 days, and 30 days post-vaccination.
• Seroprevalence and median antibody titers for poliovirus types 1, 2, and 3 were analyzed.

Main Results:

• Among 785 infants meeting study criteria, IPV recipients showed a significant increase in type 3 poliovirus seroprevalence (87.8% to 97.1%) and median antibody titer (1:228 to ≥1:1448) by day 30.
• No significant increases in type 3 seroprevalence or antibody titers were observed in infants receiving supplemental OPV doses.
• The rapid antibody titer increase in IPV recipients suggests a secondary immune response.

Conclusions:

• A supplemental dose of inactivated poliovirus vaccine (IPV) demonstrates excellent immunogenicity against type 3 poliovirus.
• IPV administration leads to a significant increase in antibody titers for type 3 poliovirus.
• Supplemental oral poliovirus vaccine doses did not elicit a comparable immune response in this study population.