JNJ-64152348

Replacing oral polio vaccines with inactivated polio vaccines (IPVs) is necessary to stop the potential transmission of vaccine-derived polio viruses. We aimed to compare the safety and immunogenicity of a dose-sparing IPV (ds-IPV) with a full-dose IPV in infants in Bangladesh.

This double-blind, randomised, controlled, phase 3 study was done at two field sites in Bangladesh (Kamlapur and Matlab). Eligible participants were healthy infants aged 6-8 weeks, with parents who intended to reside in the area during the study period. Participants were randomly assigned (1:1:1:1) to receive either ds-IPV from one of the three lots (lot A, B, or C; Serum Institute of India, Pune, India) or an IPV (Serum Institute of India). Three intramuscular doses (0·5 mL) were administered at age 6, 10, and 14 weeks in addition to other standard vaccines. The study staff involved in safety evaluation, study procedures, parents of the participants, and the laboratory personnel were masked to the treatment allocations. The primary endpoint was seroconversion for poliovirus types 1, 2, and 3 at 28 days after the third dose, assessed in the per-protocol and full analysis populations. Solicited adverse events were collected up to 4 days after each vaccine dose and unsolicited adverse events and serious adverse events were collected up to 28 days after the third dose. This study is registered with ClinicalTrials.gov, NCT05163561, and is complete.

Between Jan 9, 2022, and April 29, 2023, 1072 eligible participants were randomly assigned to receive ds-IPV (n=801) or IPV (n=267), of whom 1052 completed the study. 755 (96% [95% CI 94 to 97]) of 786 participants in the ds-IPV group versus 256 (97% [94 to 98]) of 265 participants in the IPV group had seroconversion for poliovirus type 1 (difference -0·55% [95% CI -3·05 to 1·95]). 744 (95% [93 to 96]) of 786 participants in the ds-IPV group versus 261 (98% [96 to 100]) of 265 participants in the IPV group had seroconversion for poliovirus type 2 (difference -3·83% [-6·48 to -1·19]). 765 (97% [96 to 98]) of 786 participants in the ds-IPV group versus 260 (98% [96 to 99]) of 265 participants in the IPV group had seroconversion for poliovirus type 3 (difference -0·78% [-2·73 to 1·16]). Solicited events were observed in 446 (56%) of 801 participants in the ds-IPV group and 143 (54%) of 267 participants in the IPV group. Unsolicited events were observed in 746 (93%) of 801 participants in the ds-IPV group and 250 (94%) of 267 participants in the IPV group. Serious adverse events were observed in 23 (3%) of 801 participants in the ds-IPV group and five (2%) of 267 participants in the IPV group. The common serious adverse events were pneumonia (n=10 in the ds-IPV group; n=3 in the IPV group), bronchiolitis (n=3 in the ds-IPV group; n=1 in the IPV group), and diarrhoea (n=3 in the ds-IPV group; n=1 in the IPV group). None of the unsolicited events and serious adverse events were causally related to the study vaccines.

Delivery of three intramuscular doses of the novel ds-IPV vaccine is safe and immunologically non-inferior to the delivery of three intramuscular doses of IPV, and the dose sparing formulation might therefore become an attractive option for some national immunisation programmes due to lower expected vaccine costs.

Serum Institute of India.