Recent study results published in The Lancet Infectious Diseases demonstrated that Takeda Pharmaceuticals’ live-attenuated tetravalent dengue vaccine increased seropositivity rates against dengue virus types 3 and 4 in children who were not previously exposed to infection.
The interim phase 2, randomized, double blind, placebo-controlled trial also demonstrated that in all exposure circumstances, the vaccine could produce a broad antibody response against all dengue virus types in two doses, with seropositivity ranging from 87% to 100% in the first month. Seropositivity was sustained to the end of the 6-month study (85%-100%).
The immunogenicity and safety of the tetravalent dengue vaccine (TDV) were assessed by administering one dose, two doses or a placebo to 1,794 participants aged 2 to 17 years living in the Dominican Republic, Panama and the Philippines.
“The levels of immunogenicity induced by [the vaccine] against all four dengue serotypes, even in seronegative participants, are encouraging because seropositivity after vaccination may be an important measure of vaccine performance,” researcher Xavier Sáez-Llorens, MD, head of infectious diseases and director of clinical research at the Panama Children’s Hospital, said in a press release. “Infection with one dengue serotype makes subsequent infection with a different serotype a major risk factor for severe disease, hence the need for a safe and effective vaccine that simultaneously protects against all four serotypes.”
Although there is a licensed vaccine against dengue for those aged 9 years and older — Dengvaxia (CYD-TDV, Sanofi Pasteur) — a vaccine for all ages against all four serotypes is “an urgent medical need,” according to the researchers.
“A vaccine that generates humoral and cellular immunity and shows measurable seropositivity to all dengue serotypes in most individuals, even those without previous exposure to dengue, suggests that such a vaccine is suitable for assessment in a large-scale efficacy trial,” Sáez-Llorens and colleagues wrote. “The dosing schedule chosen for this trial should generate multivalent responses in the highest proportion of individuals who were initially seronegative.”
Takeda Pharmaceuticals recently announced that it completed enrollment for a phase 3 clinical trial of its dengue vaccine candidate — known as the Tetravalent Immunization against Dengue Efficacy Study, or TIDES — which includes more than 20,000 children aged 4 to 16 years from eight dengue-endemic countries. – by Katherine Bortz
- Sáez-Llorens X, et al. Lancet Infect Dis. 2017;doi:10.1016/S1473-3099(17)30166-4
Disclosure: Sáez-Llorens reports receiving funds through his organization from Takeda Vaccines in support of this trial. Please see the full study for a list of all other authors’ relevant financial disclosures.