History of Dengue Vaccine

 

Dengue Vaccines Market

To reduce the danger of severe dengue infection in patients infected with one of the four virus serotypes not included in immunisation, experts agree that a dengue vaccine must be effective against all four virus serotypes. The only licenced dengue vaccine is Sanofi Pasteur's Dengvaxia, which is registered in several endemic countries, Europe, and the United States. This vaccine is made up of four live-attenuated chimeric viruses with the backbone of yellow fever virus, a flavivirus with a genomic organisation similar to dengue, in which the prM and E genes from the four DENV viruses have been replaced.

The global dengue vaccine market is estimated to account for US$ 1,262.0 Mn in terms of value by the end of 2027.

The vaccine was not totally protective against all serotypes, especially DENV2, according to results from phase 2 clinical trials with children in Asia. Because those youngsters had large amounts of NAb against all dengue serotypes, these findings suggested that induction of neutralising antibodies might not be enough to offer protection, and they also suggested the necessity of T-cell responses. Other DENV antigens not found in Dengvaxia, such as non-structural proteins, may be critical for generating substantial protection, according to the report. DENV seronegative patients, primarily children, became more susceptible to DHF when infected following vaccination, according to phase 4 trials conducted in the Philippines and Brazil. As a result of these findings, the WHO now exclusively recommends Dengvaxia vaccination to dengue seropositive people. Dengvaxia, on the other hand, is thought to be effective for at least 5 years in seropositive people.

Several additional vaccines have been studied in preclinical investigations using various animal models, with some of them progressing to clinical trials. Two dengue vaccines based on live-attenuated viruses are now in phase 3 studies (TV003 and TAK-003). 30 nucleotides in the 3′ UTR of DENV1, DENV3, and DENV4 were removed for attenuation, and prM/E genes from attenuated DENV4 were replaced by the identical DENV2 genes, resulting in DENV2/4. The vaccine was created by the National Institutes of Health in the United States and is being evaluated in Brazil by the Instituto Butantan (Butantan-DV). Seroconversion against the different serotypes ranged from 76 to 92 percent in phase 2 clinical trials with DENV-naive and DENV-exposed healthy individuals. CD8+ T-cell responses to non-structural dengue proteins were also associated with IFN-production in vaccinees. When DENV-exposed people were compared to DENV-naive people, neutralising antibody titers were 2–4 times greater. Furthermore, the results demonstrated a link between antibody response and the occurrence of adverse events, particularly rash.