2026-01-26 ロックフェラー大学
<関連情報>
- https://www.rockefeller.edu/news/38934-in-rare-cases-autoantibodies-can-cause-severe-reactions-to-a-live-attenuated-virus-chikungunya-vaccine-that-has-been-discontinued-in-the-u-s/
- https://www.pnas.org/doi/10.1073/pnas.2532212123
I型インターフェロン自己抗体はチクングニア熱生弱毒化ワクチン脳炎の原因となる Type I IFN autoantibodies underlie chikungunya live-attenuated vaccine encephalitis
Adrian Gervais, Paul Bastard, Qian Zhang, +18 , and Jean-Laurent Casanova
Proceedings of the National Academy of Sciences Published:January 22, 2026
DOI:https://doi.org/10.1073/pnas.2532212123
Significance
Autoantibodies that block type I interferons (IFNs) have recently been recognized as major causes of a growing number of life-threatening viral infections. We report that these autoantibodies also explain severe brain inflammation in elderly individuals following vaccination with the live-attenuated chikungunya virus (CHIKV) vaccine, VLA1553 (IXCHIQ®). This finding reveals that type I IFN-neutralizing autoantibodies can cause severe adverse reactions to live-attenuated CHIKV vaccines, as they do for yellow-fever vaccines. Identifying individuals with these autoantibodies before vaccination could prevent such outcomes and improve vaccine safety for older adults.
Abstract
Human autoantibodies neutralizing type I interferons (IFNs) have emerged as strong, common, and global determinants of a growing number of severe viral diseases, including hypoxemic viral pneumonia, arboviral encephalitis, and adverse reaction to the live-attenuated yellow fever virus (YFV) vaccine. Chikungunya virus (CHIKV) is a growing global health concern that the live-attenuated vaccine VLA1553 (IXCHIQ®) was developed to address. In 2025, five unrelated adults (aged 82 to 88) on the island of La Réunion (France) developed severe reactions postvaccination; two died. The three patients with encephalitis (aged 84 to 85), including one lethal case, had immunoglobulin G autoantibodies in the blood neutralizing high concentrations of both IFN-α and -ω on admission. An 82-y-old survived rhabdomyolysis without encephalitis, and an 88-y-old died during hospitalization following CHIKV infection despite late vaccination; both lacked autoantibodies against type I IFNs. Autoantibodies neutralizing type I IFNs underlie all three cases of live-attenuated CHIKV vaccine encephalitis studied. Individuals with autoantibodies neutralizing type I IFNs should not be inoculated with live-attenuated YFV and CHIKV vaccines.
