Document text
Work Group interpretation of data for
virus -like particle chikungunya vaccineNational Center for Emerging and Zoonotic Infectious Diseases
Susan Hills MBBS MTH
CDC Lead , Chikungunya Vaccines Work Group
Arboviral Diseases Branch
Division of Vector -Borne Diseases
Fort Collins , Colorado
ACIP Meeting, October 23, 2024
•No vaccine effectiveness data
•Short -term* immunogenicity data available from ~2,750
vaccinated subjects in two Phase 3 studies
-Majority adults aged 18 –64 years (~2350 subjects)
-Smaller numbers of adolescents aged 12 –17 years and older adults
aged ≥65 years (~200 subjects in each group)Vaccine effectiveness (immunogenicity) data availability
*Seroresponse rates at 21 days after vaccination
2
•Robust response to vaccination with seroresponse rates* at 21 days
after vaccination of 98% in adolescents/younger adults vs. 87% in
older adults
•Relatively good seroresponse rates maintained at 6 months after
vaccination with rates in younger and older age groups of 86% vs. 76%
•No longer -term (>6 months) data available from Phase 3 studies so
need for booster dose unknownKey immunogenicity results
*Percent of subjects with anti -chikungunya virus 80% serum neutralizing antibody titer ≥100 3
•Safety data available from ~3,000 vaccinated subjects in
two Phase 3 studies
-Majority adults aged 18 –64 years (~2,580 subjects)
-Smaller numbers of adolescents aged 12 –17 years and older adults
aged ≥65 years (~210 subjects in each group)Safety data availability
4
•Solicited adverse events within 8 days of vaccination
-Local: 24%; severe in 0.2%; m ostly injection site pain
-Systemic: 32%; severe in 1.5%; fatigue, headache, and myalgia in 1 8%–20%
•New onset or worsening arthralgia requiring medical attention in 0.2%
•One serious adverse event (i.e., retinal detachment) assessed as related
by investigator but unrelated by safety monitoring committee chair
•All rates lower in older adults aged ≥65 yearsKey safety results in adolescents and adults aged 12 –64 years
5
•Will provide option, in addition to the licensed live attenuated vaccine, for
vaccination of adults aged ≥18 years
•Will provide option for adolescents aged 12 –17 years
•Immunogenic vaccine but no vaccine effectiveness data which will be gathered post -licensure, and need for booster dose currently unknown
•No apparent safety concerns but safety data only from ~3,000 people so
insufficient to detect rare events, and post -marketing surveillance important
•Work Group to conduct comprehensive data review and present GRADE assessment as part of Evidence to Recommendations framework at future meetingWork Group summary for chikungunya virus- like
particle vaccine
6
Chikungunya Vaccines Work Group plans
Anticipated votes on vaccine recommendations, 2025
Population Live attenuated vaccine Virus -like particle vaccine
Travelers≥18 years completed
YES†
YES*
Laboratory workers Completed YES
Residents of U.S. territories
with transmission risk YES YES
Residents of U.S. states with transmission risk YES YES
*12– 17 years †≥12 years
For more information, contact CDC
1-800- CDC- INFO (232 -4636)
TTY: 1 -888- 232- 6348 www.cdc.gov
The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.