BACKGROUND: CYD-TDV is a recombinant, live-attenuated tetravalent vaccine indicated for the prevention of dengue disease. As a “first in class” vaccine, CYD-TDV requires further safety evaluation in real-world immunization settings. METHODS: DNG15 is a prospective, multinational, non-interventional cohort event monitoring study utilizing active surveillance to identify adverse events (AEs) of interest after CYD-TDV vaccination: allergic and anaphylactic reactions, epilepsy or convulsions, hospitalized dengue disease, Yellow Fever vaccine-associated neurotropic (YEL-AND) and viscerotropic (YEL-AVD) disease, as well as any other serious adverse events (SAEs). Participants were enrolled immediately after their first CYD-TDV dose, primarily from public vaccination centers in the Philippines and Brazil (Paraná), as well as from private clinics in Mexico. They were contacted 3 times at 6-week intervals after each dose (short-term surveillance) and then quarterly up to 5-years after their first dose (long-term surveillance). All data collected between 13 December 2016 (study start) and 23 August 2021 were included in this interim analysis. Adverse event rates and 95% confidence intervals were calculated among those with at least one contact post-vaccination.
OBJECTIVES: To evaluate short- and long-term safety of CYD-TDV when used in real-world immunization settings.
RESULTS: The cohort comprised 12,594 eligible participants, 10,829 (86%) of whom had at least one follow-up contact. The median age of participants was 11 years (range: 7.0 - 73.0 years) and 51% were female. Just over 91% of participants received only 1 dose of CYD-TDV, while 5.1% and 3.7% received 2 and 3 doses, respectively. Overall, 5.9% (95% CI, 5.5-6.4; n=644) of participants reported at least one AE (serious and nonserious). Eleven reported an allergic reaction (0.1%; 95% CI, 0.1-0.2), all during short-term surveillance, 10 of which were assessed as related to CYD-TDV, and none being anaphylaxis. Six participants reported seven episodes of epilepsy or convulsions (< 0.1%; 95%CI, 0.0-0.1), none assessed as related and 57.1% reported during short-term surveillance. There were 104 cases of hospitalized dengue disease (1.0%; 95% CI, 0.8-1.2) most during long-term surveillance, none of which were fatal or assessed as related, with all but one categorized as non-severe. There were 235 participants who reported at least one other SAE (2.2%; 95% CI, 1.9-2.5), most during long-term surveillance and none considered related. No cases of YEL-AND or YEL-AVD have been reported to date.
CONCLUSIONS: CYD-TDV was found to be well tolerated in this large cohort study conducted in real-world settings. No safety concerns were identified during either the short- or long-term surveillance period.
