Document text
National Center for Emerging and Zoonotic Infectious Diseases
Value of a vaccine to prevent travel -related
chikungunya for US persons
Nicole Lindsey, MS
CDC Deputy Lead , Chikungunya Vaccines Work Group
Arboviral Diseases Branch
Centers for Disease Control and PreventionJune 22, 2023
Potential value of a chikungunya vaccine among
international travelers (Valneva survey)
2021 online survey of 2,002 US residents aged ≥ 18 years who either
travelled internationally in last 3 years or planned to do so in next 3 years
–Excluded anyone who self -identified as ‘anti -vaccination’
Limited information provided about the surveyed population
Participants provided basic information about chikungunya disease
–Disease distribution, symptoms of disease, rarely joint pain/fatigue that lasts
for months or years, and lack of treatment
–No information on risk of infection, potential adverse events, costs of vaccineAwareness of chikungunya and value of a chikungunya
vaccine among travelers
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Only 18% had heard of chikungunya prior to survey
After participants provided information about chikungunya, asked two
questions:
–How likely would you be to ask a healthcare professional about a vaccine to
protect yourself against chikungunya? 72% Likely
–If a doctor or health care provider recommended the chikungunya vaccine for you, how likely would you be to get vaccinated? 81% LikelyAwareness of chikungunya and value of a chikungunya
vaccine among travelers
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Low awareness of chikungunya virus disease among traveler population
Most would likely ask healthcare provider about a chikungunya vaccine
and be vaccinated if their provider recommended vaccination
Limitations
–No info rmation provided to participants about risk of disease or
risks/benefits of vaccination
–No information about co sts
–Although traveler population, unknown if representative of traveler
population to areas at risk for chikungunyaAwareness of chikungunya and value of a chikungunya
vaccine among travelers: Summary
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Potential value of a chikungunya vaccine among U.S.
persons (CDC survey)
Method: Porter Novelli Consumer Styles surveys
Online panel representative of non -institutionalized U.S. population
–Members randomly recruited using probability -based sampling by address
–Provided with a laptop or tablet and access to internet if needed
–Receive small monetary rewards for participation
2022 Summer Styles respondents included 4,156 invited adults (69%
response rate)
Core questions capture demographic information in addition to consumer attitudes, values, and behaviors
Data weighted to U.S. Population Survey proportions for sex, age, household income, race/ethnicity, household size, education, census region
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Questions on value of a chikungunya vaccine
1.Imagine you are going on a trip to another country. You have a 1 in 150
chance of getting a disease. About 1 in 4 people who get the disease
suffer from long -term joint pain. A vaccine is available that costs $350
and is not covered by insurance. How likely would you be to get the
vaccine?
2.Now imagine you are going on the same trip, but your chances are 1 in
15,000 of getting the disease. About 1 in 4 people who get the disease
suffer from long -term joint pain. The vaccine costs $350 and is not
covered by insurance. How likely would you be to get the vaccine?
3.Which factors are most important to you in deciding whether or not to get the vaccine?
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50% female; median age 54 years (range: 18- 94 years)
72% identified as white, non- Hispanic
Education
–5% with less than high school education
–25% with high school education
–70% with at least some college or higher education
Household income
–<$25K: 10%
–$25- <$75K: 30%
–≥$75K: 60% Demographics of survey participants (N=4,156)
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Imagine you are going on a trip
to another country. You have a
1 in 150 chance of getting a
disease. About 1 in 4 people who get the disease suffer from
long -term joint pain. A vaccine
is available that costs $350 and is not covered by insurance. How likely would you be to get
the vaccine? (n=4,146)
*Includes very and somewhat likely responses
**Includes very and somewhat unlikely responses42%
26%32%
Likely* Unsure Unlikely**
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Likelihood of chikungunya vaccination by age group
where disease risk is 1 in 150
45%43%43%35%
26%26%24%28%
30%31%33%37%
70+50-6930-4918-29
Likely Not Sure Unlikely
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Likelihood of chikungunya vaccination by sex where
disease risk is 1 in 150
39%44%
29%22%
32%33%
FemaleMale
Likely Not Sure Unlikely
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Likelihood of chikungunya vaccination by
race/ethnicity where disease risk is 1 in 150
51%42%36%42%
26%21%35%25%
24%37%29%33%
OtherHispanicBlackWhite
Likely Not Sure Unlikely
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Likelihood of chikungunya vaccination by education
where disease risk is 1 in 150
54%41%31%
19%26%32%
27%33%38%
College and higherSome collegeHigh school or less
Likely Not Sure Unlikely
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Likelihood of chikungunya vaccination by household
income where disease risk is 1 in 150
51%38%31%22%
22%29%27%36%
27%33%42%42%
75K+50-74K25-49K<25K
Likely Not Sure Unlikely
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Likelihood of chikungunya vaccination where disease
risk is 1 in 150: Summary
42% respondents likely to be vaccinated when disease risk is high
–About a third unlikely to be vaccinated even in high -risk scenario
–About a quarter unsure
Main differences by group
–Lower likelihood of vaccination among youngest age groups, those with lower
education and household income levels
–Blacks less likely to be vaccinated and more likely to report ‘unsure’
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Now imagine you are going on
the same trip, but your
chances are 1 in 15,000 of
getting the disease. About 1 in 4 people who get the disease
suffer from long -term joint
pain. A vaccine is available that
costs $350 and is not covered
by insurance. How likely would
you be to get the vaccine?
(n=4,138)27%
24%49%
Likely* Unsure Unlikely**
*Includes very and somewhat likely responses
**Includes very and somewhat unlikely responses 23
Likelihood of chikungunya vaccination where disease
risk is 1 in 15,000: Summary
Level of risk is important factor in determining likelihood of vaccination
with 27% being likely to vaccinate in low -risk scenario compared to 42% in
higher risk scenario
About a quarter of respondents unsure for both risk level scenarios
Similar trends for different demographic factors between high and low risk scenarios, with responses more towards ‘unlikely’ end of scale
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Which factors are most important to you in deciding
whether or not to get the vaccine? (n=4,130)
6%11%36%41%43%57%
I do not get any vaccinationsOther factors not listedChance of getting long-term joint painCost of the vaccineChance of side effects from the vaccineChance of getting the disease
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Not many differences by age
–Youngest age group more concerned about costs and less about long -term
joint pain
–Middle aged (45 -59 years) most concerned about vaccine side effects
No meaningful differences by sex or race/ethnicity
Importance of risk of disease and risk of long -term joint pain following
infection increased with both education level and household income
Conversely, proportion of respondents that do not receive vaccination
decreased by increasing education and incomeDifferences in factors influencing vaccination by
demographics
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Factors influencing vaccination in high- risk scenario
by likelihood of vaccination
71%
51%
40%
33%
1%44%
21%42%51%
14%
Chance of getting
diseaseChance of long-term
joint painChance of side
effects from vaccineCost of the vaccine I do not get any
vaccinationsLikely
Unlikely
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Factors influencing vaccination in lower risk scenario
by vaccine acceptance
68%
53%
40%
27%
1%55%
28%43%51%
9%
Chance of getting
diseaseChance of long-term
joint painChance of side
effects from vaccineCost of the vaccine I do not get any
vaccinationsLikely
Unlikely
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Factors influencing likelihood of vaccination:
Summary
Most commonly reported factor was risk of getting disease, which is
consistent with findings for high and low risk scenario questions
Also important are risk of side effects, vaccine cost, and risk of long -term
join pain following infection
Significant differences between those likely and unlikely to be vaccinated in importance of factors, with exception of concern about side effects
–For “likely to be vaccinated” key factors were chance of disease and chance of
long -term joint pain
–For “unlikely to be vaccinated”, key factors were vaccine cost and chance of disease
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Survey limitations
Not a traveler population
–Unknown how well these responses reflect attitudes of a traveler population
Only very basic disease information provided
No information on likelihood or type of side effects from vaccination
Vaccine cost was estimate based on typical travel vaccine not actual cost
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Potential value of a chikungunya vaccine among U.S.
persons: Summary
42% of respondents likely to be vaccinated when disease risk is high; 27%
when disease risk is low
–About a quarter of participants were unsure in both scenarios
Lower likelihoods of vaccination than reported in Valenva survey (81%),
but were important differences in methods
–Traveler vs general population
–Different background information provided – more general information on
chikungunya vs. information focusing on disease risks, sequela, and costs
–Response to question on “likelihood of getting vaccine if recommended by
healthcare provider” vs “likelihood of getting vaccine”
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Awareness of chikungunya and value of a
chikungunya vaccine to U.S. travel healthcare
providers (Valenva survey)
Online survey conducted in 2021 of 158 US travel healthcare providers
–All participants routinely preform pre -travel health counseling and prescribe
and/or administer relevant travel vaccines
–Mix of provider types and practice settings relevant to travel health
How familiar, if at all, are you with chikungunya disease?
–Familiar with disease and have clinical knowledge of it (30%)
–Have heard of it but don’t know what it is (20%)
–Majority not familiar (51%)Awareness of chikungunya and value of a vaccine to
U.S. travel healthcare providers
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Value of chikungunya vaccine to U.S. travel
healthcare providers
Participants provided information:
–Disease epidemiology, clinical presentation, types and duration of sequelae
–Chikungunya vaccines likely available within few years
Asked to indicate likelihood to recommend/prescribe a vaccine for
chikungunya if recommended by ACIP
–15% Very likely
–73% Somewhat likely–11% Neither likely nor unlikely
–1% Unlikely
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Low awareness of and familiarity with chikungunya among U.S. healthcare
providers, even among those who work in travel medicine
Following minimal education, 88% of providers surveyed would be likely to recommend/administer vaccine to travelers if recommended by ACIP
–Explicit in question that vaccination would be recommended by ACIP
–No estimates of risk of disease or possible risks of vaccination Awareness of chikungunya and value of a vaccine to
U.S. travel healthcare providers: Summary
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Value of chikungunya vaccine to U.S. travelers and
healthcare providers: Summary
Awareness of chikungunya low among travelers and healthcare providers
Healthcare providers likely to prescribe vaccination as recommended by
ACIP and travelers interested in vaccination if recommended by provider
Independent of healthcare provider recommendation, about 30– 40% of
U.S. persons interested in vaccination and remainder unsure or unlikely to
be vaccinated
–Variability in population perception of whether potential desirable effects
outweigh undesirable effects
–Risk of disease, vaccine cost, vaccine side effects, and risk of chronic arthralgia are influential factors in deciding on chikungunya vaccination
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