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National Center for Emerging and Zoonotic Infectious Diseases
UPDATE ON LICENSURE OF LIVE
ATTENUATED CHIKUNGUNYA VACCINE
Susan Hills, MBBS, MTH
CDC Lead , Chikungunya Vaccines Work Group
Arboviral Diseases Branch
Division of Vector -Borne Diseases
Fort Collins, Colorado
ACIP meeting, February 28, 2024
Key points from FDA licensure and package insert
Vaccine approved on November 9, 2023 and named IXCHIQ
Indicated for individuals at increased risk of exposure to chikungunya virus
Single dose primary schedule and for use in individuals aged ≥18 years
Contraindications
Immunocompromised individuals
Individuals with a history of a severe allergic reaction (e.g.,
anaphylaxis) to any component of IXCHIQ
2
Warnings and precautions in package insert
Vaccine may cause severe or prolonged chikungunya -like adverse
reactions
Vaccine viremia occurs in the first week following vaccination and
no data on risk of vertical transmission to fetus or neonate
Licensure through accelerated approval pathway
Tradition approval would have been challenging and clinical development
would likely have been delayed
–Chikungunya outbreaks unpredictable and duration can be relatively short
–No established immunologic correlate of protection
Accelerated approval pathway endorsed at FDA VRBAC* meeting, 2019
–FDA can grant for products for serious conditions that fill unmet medical need
–Effectiveness demonstrated by controlled clinical trials showing vaccine has effect
on surrogate endpoint reasonably likely to predict clinical benefit
–Marker of protection for chikungunya vaccine based on neutralizing antibody titer estimated from validated non -human primate model
–Post-licensure requirement for controlled trials to confirm the clinical benefit
*Vaccines and Related Biological Products Advisory Committee
Required post -marketing studies
Vaccine effectiveness case -control study in persons aged ≥12 years,
Brazil
–Plan to initiate by March 2026, complete by March 2028
Pragmatic randomized controlled trial for effectiveness and safety in
adults in endemic area
–Plan to initiate by Oct 2025, complete by Jul 2029