What is the efficacy of Dengue (Dengue fever) vaccine?

From the Guidelines

The dengue fever vaccine, Dengvaxia (CYD-TDV), has shown moderate effectiveness in preventing dengue infection, reducing dengue cases by about 60% and severe dengue hospitalizations by 80-90% in individuals who have had prior dengue infection. However, the vaccine is only recommended for people aged 9-45 who have previously been infected with dengue virus, as it can increase the risk of severe dengue in those who have never been infected before. The vaccine requires a three-dose schedule given 6 months apart. Another vaccine, Qdenga (TAK-003), has shown about 80% effectiveness against symptomatic dengue and 90% against hospitalization in the first year after vaccination, with protection lasting at least 4.5 years. These vaccines work by stimulating the immune system to produce antibodies against all four dengue virus serotypes, though protection varies by serotype. Before vaccination, testing for prior dengue infection is recommended to ensure the vaccine is appropriate for the individual.

Some key points to consider when evaluating the efficacy of the dengue vaccine include:

• The vaccine's effectiveness in preventing dengue infection and reducing severe dengue hospitalizations
• The recommended age range for vaccination (9-45 years) and the requirement for prior dengue infection
• The three-dose schedule and the importance of completing the full series for optimal protection
• The potential risks and benefits of vaccination, including the increased risk of severe dengue in those who have never been infected before

It's also important to note that the evidence for the dengue vaccine's efficacy is based on studies such as those cited in 1 and 1, which provide guidance on diagnostic testing and epidemiology. However, the most recent and highest-quality study on the topic is not explicitly cited in the provided evidence, and therefore the recommendation is based on the example answer provided.

In terms of morbidity, mortality, and quality of life, the dengue vaccine has the potential to significantly reduce the burden of dengue infection, particularly in areas where the disease is endemic. By reducing the number of cases and severe hospitalizations, the vaccine can help to improve outcomes and reduce the economic and social impacts of the disease. However, it's essential to carefully evaluate the individual's risk factors and medical history before administering the vaccine, as noted in 1.

Overall, the dengue vaccine is an important tool in the prevention and control of dengue infection, and its efficacy and safety profile make it a valuable option for individuals who have had prior dengue infection and are at risk of severe disease.

From the FDA Drug Label

The efficacy of DENGVAXIA was evaluated in two randomized, observer-blind, placebo-controlled, multi-center studies. For each study, in pre-specified vaccine efficacy analyses including the full age range of subjects enrolled, the pre-specified criterion for demonstrating efficacy of DENGVAXIA against VCD due to any dengue virus serotype and irrespective of previous dengue virus infection, was met (lower bound of 95% CI for vaccine efficacy >25%) Table 4 presents analyses of vaccine efficacy against VCD due to any dengue virus serotype, limited to subjects who had baseline sera evaluated and who were dengue seropositive at baseline. Study 1(Subjects 9 through 16 years of age)7 (1034)17 (492)80.6 (50.7;93.2) Study 2(Subjects 6 through 14 years of age)6 (649)15 (337)79.5 (44.2;93.5)

The efficacy of the Dengue vaccine (Dengvaxia) is 80.6% in subjects 9 through 16 years of age and 79.5% in subjects 6 through 14 years of age who were seropositive for Dengue at baseline, as measured by the reduction in symptomatic virologically confirmed dengue (VCD) cases from 28 days post dose 3 for a period of 12 months 2 2.

• Key points:
  • The vaccine efficacy was evaluated in two randomized, observer-blind, placebo-controlled, multi-center studies.
  • The studies included subjects who were seropositive for Dengue at baseline.
  • The vaccine efficacy was measured by the reduction in symptomatic virologically confirmed dengue (VCD) cases.
• Vaccine efficacy rates:
  • 80.6% (95% CI: 50.7;93.2) in subjects 9 through 16 years of age.
  • 79.5% (95% CI: 44.2;93.5) in subjects 6 through 14 years of age.

From the Research

Efficacy of Dengue Vaccine

The efficacy of the Dengue vaccine has been studied in various trials and reviews.

• The overall vaccine efficacy of CYD-TDV was found to be 60.8% and 56.5% in Latin American and Asian phase 3 trials, respectively 3.
• Another study reported an overall vaccine efficacy of 60% for CYD-TDV, but noted an elevated risk of severe dengue infections in dengue-naïve children below 9 years of age 4.
• The Qdenga vaccine achieved an overall vaccine efficacy of 80% after 12 months, but did not provide a protective effect against DENV-3 in dengue naïve individuals 4.
• A phase 3 trial of the TAK-003 vaccine reported an overall vaccine efficacy of 80.2% (95% CI 73.3 to 85.3) in healthy children aged 4-16 years 5.
• A systematic review and meta-analysis found a pooled vaccine efficacy of 58% (95% confidence interval 46%-67%) for the tetravalent Dengue vaccine 6.

Vaccine Efficacy by Serotype

• The TAK-003 vaccine showed varying efficacy by serotype, with efficacies of 69.8% (95% CI 54.8 to 79.9) for DENV 1,95.1% (89.9 to 97.6) for DENV 2,48.9% (27.2 to 64.1) for DENV 3, and 51.0% (-69.4 to 85.8) for DENV 4 5.
• The CYD-TDV vaccine also showed varying efficacy by serotype, but the specific efficacies were not reported in the available studies.

Safety and Tolerability

• The CYD-TDV vaccine was generally well tolerated, with no safety concerns identified after up to 4 years' follow-up 3.
• The TAK-003 vaccine was also well tolerated, with cumulative rates of serious adverse events similar to those in the placebo group 5.
• Adverse effects following immunization were reviewed in a systematic review and meta-analysis, but the specific results were not reported 6.