Six-month IXCHIQ chikungunya vaccine data demonstrates sustained antibody levels

Six-month IXCHIQ chikungunya vaccine data demonstrates sustained antibody levels | Image Credit: © Monir - © Monir - stock.adobe.com.

Among children aged 1 to 11 years, new data for Valneva's chikungunya vaccine, IXCHIQ, revealed antibody persistence and safety for up to 6 months for the single-shot vaccine in both half- and full-dose levels, according to a press release from Valneva.¹

In the phase 2 VLA1553-221 trial (NCT06106581), a full dose elicited a more robust immune response in the patient population at day 15 and day 180 post-vaccination compared to a half dose. Overall immunological response was in line with previously announced data, demonstrating tolerability and a safety profile that was similar to adolescents and adults. The primary and secondary objectives of the trial are to evaluate the safety and immunogenicity of 2 different dose levels of the vaccine.

Among CHIKV-naïve children, a 96.5% seroresponse rate was observed for the full dose at day 180. Regardless of dose or previous infection, VLA1553 was well-tolerated with no safety concerns identified. Regarding safety and tolerability, in addition to the more pronounced immune response of the full dose for all age groups tested in children up to 180 days post-vaccination, Valneva stated these observations support the full-dose use for this population.

In the multi-center, randomized, observer-blinded, dose-response trial among 304 healthy children aged 1 to 11 years, individuals were randomized 2:2:1 to receive either a full dose, half dose, or an active control (Nimenrix).

"The 6-months persistence and safety data in children are aligned with the robust antibody response and safety profile we reported in adolescents after a single vaccination," stated Juan Carlos Jaramillo, MD, chief medical officer, Valneva, in a press release. "Considering the significant risk chikungunya poses to individuals living in or traveling to endemic areas, it’s crucial to ensure that the vaccine is accessible to people of all ages and capable of potentially offering long-term protection from a single shot. This is especially important in Low- and Middle-Income countries where access to vaccines is often limited.”

Currently, IXCHIQ is approved by the FDA for the prevention of disease caused by CHIKV in individuals aged 18 years and older who are at an increased risk of CHIKV exposure.^2,3

References:

1. Valneva reports positive six-month antibody persistence and safety phase 2 results in children for its single-shot chikungunya vaccine IXCHIQ. Valneva SE. Press release. June 5, 2025. Accessed June 5, 2025. https://valneva.com/press-release/valneva-reports-positive-six-month-antibody-persistence-and-safety-phase-2-results-in-children-for-its-single-shot-chikungunya-vaccine-ixchiq/https://valneva.com/press-release/valneva-reports-positive-six-month-antibody-persistence-and-safety-phase-2-results-in-children-for-its-single-shot-chikungunya-vaccine-ixchiq/

2. Fitch J. IXCHIQ chikungunya vaccine meets phase 2 endpoint in children. Contemporary Pediatrics. January 23, 2025. Accessed June 5, 2025. https://www.contemporarypediatrics.com/view/ixchiq-chikungunya-vaccine-meets-phase-2-endpoint-in-children

3. Fitch J. World’s first chikungunya vaccine FDA approved for individuals 18 years and up. Contemporary Pediatrics. November 10, 2023. Accessed June 5, 2025. https://www.contemporarypediatrics.com/view/world-s-first-chikungunya-vaccine-fda-approved-for-individuals-18-years-and-up