Clinical Study to Assess the Immunogenicity and Safety of Hexavalent Vaccine Containing Reduced Dose IPV

Overview

In 2012, the World Health Assembly (WHA) endorsed the proposed Polio Endgame Strategy, which includes withdrawal of the Sabin-virus type 2 antigen-responsible for an estimated 95% of vaccine derived cases of polio by replacing the trivalent Oral Polio Vaccine (OPV) in the routine immunization schedule with a bivalent OPV that lacks the type 2 Sabin virus. Since the WHA resolution, all countries that were solely using OPV have either introduced Inactivated Polio Vaccine (IPV) into their routine immunization schedule or decided to introduce IPV but have been unable to secure supply. The global demand for IPV has therefore substantially increased in just a few years. Many initiatives are ongoing to meet the increasing demand for IPV. One potential approach is the reduction of the amount of antigen per vaccine dose. Therefore, to enhance the affordability, effectiveness and accessibility of IPV. SIIPL has manufactured hexavalent combination vaccine containing diphtheria, tetanus, pertussis, hepatitis B, Haemophilus influenzae type b and a reduced dose of three IPV antigens. Based on available published data, reduction of the antigen content of each of the three poliovirus types in IPV is feasible, without substantially compromising the immunogenicity of the vaccine. Advantages of a reduction in antigen content are two-fold: increased availability of IPV and reduced cost, both of major importance for the global eradication programme.

This is an observer-blind, randomized, active-controlled, multi-centric study in healthy infants and toddlers to assess the immunogenicity and safety of SIIPL reduced IPV hexavalent vaccine in comparison with the licensed SIIPL HEXASIIL® vaccine. One thousand five hundred and fifty-seven infants aged 6-8 weeks (42 to 56 days, both days inclusive) will be randomized in a 2:1 ratio (1038 infants in SIIPL reduced IPV hexavalent group and 519 in SIIPL HEXASIIL® group), to receive a 3-dose primary vaccination series followed by their booster doses, respectively. The safety and immunogenicity data collected up to 28 days following third vaccination i.e., Visit 7, shall be submitted to the regulatory authority. All subjects will be followed up further for booster dose. After Visit 7 (i.e., 28 days following completion of primary vaccination series) subjects will be followed up for safety every 3 months starting from the age of 6 months (i.e., at 6, 9, 12, 15, 18, and 21 months of age) until they receive the booster dose anytime between 12-24 months. There will be post booster follow up visit (EOS visit) 28 days after the booster immunization i.e., Visit 10 to assess the safety and post booster immunogenicity.