Chikungunya is a viral infection transmitted by mosquitoes. While the disease is more prevalent in Africa and India, it has been reported worldwide. This study aims to assess the safety and immunogenicity of the newly developed single-shot live-attenuated chikungunya virus (CHIKV) vaccine.

This randomized, dose-escalation, single-blind, phase 1 study included a total of 120 healthy adults (aged 18-45 years). The participants were randomly assigned in a 1:1:2 ratio to receive a single shot of one of three escalating doses of the vaccine. The participants were revaccinated at month 6 or 12 and were followed-up for 28 days. The primary outcome of the study was the safety of the vaccination, along with immunogenicity analysis in participants who completed the study.

Out of 120 participants, 31 were assigned to low, 30 to medium, and 59 to a high dose of the vaccine. The findings suggested that the vaccine was well-tolerated in low-dose and medium-dose groups, and was safe in the high-dose group. A total of 11 (36%), 12 (40%), and 40 (68%) in the low-dose, medium-dose, and high-dose groups, respectively reported some types of solicited system reaction. All participants showed good immunogenicity profile with 100% seroconversion rates at day 14.

The research concluded that single-shot live-attenuated CHIKV vaccine was safe and highly immunogenic in healthy adults.