Acceptability of hypothetical dengue vaccines among travelers.

Background: Dengue viruses have spread widely in recent decades and cause tens of millions of infections mostly in tropical and subtropical areas. Vaccine candidates are being studied aggressively and may be ready for licensure soon.

Methods: We surveyed patients with past or upcoming travel to dengue-endemic countries to assess rates and determinants of acceptance for four hypothetical dengue vaccines with variable efficacy and adverse event (AE) profiles. Acceptance ratios were calculated for vaccines with varied efficacy and AE risk.

Results: Acceptance of the four hypothetical vaccines ranged from 54% for the vaccine with lower efficacy and serious AE risk to 95% for the vaccine with higher efficacy and minor AE risk. Given equal efficacy, vaccines with lower AE risk were better accepted than those with higher AE risk; given equivalent AE risk, vaccines with higher efficacy were better accepted than those with lower efficacy. History of Japanese encephalitis vaccination was associated with lower vaccine acceptance for one of the hypothetical vaccines. US-born travelers were more likely than non-US born travelers to accept a vaccine with 75% efficacy and a risk of minor AEs (p = 0.003). Compared with North American-born travelers, Asian- and African-born travelers were less likely to accept both vaccines with 75% efficacy.

Conclusions: Most travelers would accept a safe and efficacious dengue vaccine if one were available. Travelers valued fewer potential AEs over increased vaccine efficacy.