Safety, immunogenicity and lot-to-lot consistency of a new Bivalent Oral Polio Vaccine (bOPV) in healthy Infants: Results of a Phase III, observer blind, randomized, controlled clinical study

Abstract Background Poliomyelitis infection continues to be endemic in few countries despite rigorous efforts for eradication. A new Bivalent Oral Polio Vaccine (BBio bOPV) was tested in a Phase III Clinical study. Methods An observer blind, randomized, controlled clinical study was conducted comparing BBio bOPV with a licensed bOPV (SII bOPV). Initially in Part 1, 40 children 5–6 years of age were given a single dose of either vaccine in 1:1 ratio. In Part 2, 1080 infants of 6–8 weeks of age were received in 1:1:1:1 ratio one of the 3 lots of BBio bOPV or SII bOPV at 6, 10 and 14 weeks of age. Blood samples were collected to assess neutralizing antibody responses against Polio Type 1 and 3 viruses. Safety of the vaccines were recorded. Results All children were seroprotected against both Type 1 and Type 3 polioviruses post-vaccination. More than 96% of the infants demonstrated seroconversion as well as seroprotection against both types of polioviruses. The geometric mean titres (GMT) for Type 1 and Type 3 antibodies were comparable between the groups. The 3 lots of BBio bOPV generated similar GMTs of Type 1 and Type 3 antibodies. In total 387 participants reported at least one adverse event and 18 serious adverse events. None of these events were vaccine related. Conclusions The new bOPV vaccine demonstrated immunogenicity that was non-inferior to a licensed bOPV vaccine. Consistency in immune response by 3 consecutively manufactured lots was also demonstrated. The vaccine did not cause any adverse event. Clinicaltrials.gov.identifier: NCT02766816 .