Table 3.

The US FDA’s approval of Valneva’s IXCHIQ brought the world’s first chikungunya vaccine to market—Clinical Trials Arena.

Phase	Focus	Key findings
Phase I	Safety and immunogenicity	The Phase I trials were conducted on a few healthy volunteers, and the findings are not publicly available.
Phase II	Safety and immunogenicity	In the Phase II trials, a single dose of IxChiq, a live attenuated vaccine, developed viral resistance in 98% of those tested after 28 days, and 85% still showed resistance after one year. However, 8% of people reported transient joint pain.
Phase III	Safety and efficacy	In the pivotal Phase III data reported in 2022, IxChiq demonstrated a 98.9% (263 of 266 subjects tested for immunogenicity) seroresponse rate at 28 days with a single vaccination. 233 of 242 subjects tested for immunogenicity, seroresponse rates at 28, 84, and 180 days postvaccination were 98.9, 98.0, and 96.3%, respectively.