What we do

GDAC provides leadership, promotes innovations and strategies in all fields that contribute to the sustainable control of Aedes-transmitted diseases, with a particular focus on dengue, Zika, chikungunya and yellow fever.

We champion an integrated approach

GDAC adopts a holistic approach based on integrating several strategies to combat Aedes-transmitted diseases.

Promising new tools such as vaccines, therapeutics and vector control methods are being developed, but none will likely halt the spread of Aedes-transmitted diseases if used alone. Each endemic country is epidemiologically, ecologically and culturally unique, and will need to determine the most cost-effective and synergistic way to implement these tools. High quality clinical management, disease and vector surveillance data, reliable diagnostics, trained staff and coordinated application will be required at a local, national and international level.

At the interface between several disciplines, the GDAC consortium promotes cross-fertilization and has created unprecedented opportunities for scientists from different fields to leverage their combined expertise and fill important knowledge gaps.

We tackle tough questions

Our workshops and publications address questions such as:

– What are best practices for vector control and vaccination?
– What are the most promising vaccines and vector control tools in the development pipeline?
– What is the most effective way to measure synergies between vector control and vaccination?
– What are the best diagnostic tools for surveillance and clinical management?

Our taskforces

GDAC taskforces are think tanks where leading experts identify and assess new developments, draft recommendations and suggest topics for PDC-sponsored workshops.

For example, our Vector Control Taskforce has delivered key outcomes about the most effective vector control methods, critical endpoints for clinical trials, and the design of trials to assess synergies between vector control and vaccination for the prevention of human dengue disease.

A more recent taskforce has elaborated pre-vaccination screening strategies for the dengue vaccine.

Our initiatives

Through GDAC taskforces, workshops, scientific publications, advocacy and video campaigns, we design and implement initiatives that bring us closer to the goal of sustainable control and prevention of dengue and other Aedes-transmitted diseases.

Our 3 workstreams

Our triple focus encompasses 3 major workstreams:

– Prevention through vector control
– Prevention through vaccination
– Surveillance

Vector control

Vector control must be an integral part of every successful program to control Aedes-transmitted diseases. When there is no vaccine or cure, controlling mosquito vector populations or interrupting human–vector contact are the only methods proven to be effective to control mosquito-borne diseases.

However, data on its impact on diseases such as dengue, chikungunya, yellow fever and Zika, suggest that as currently practiced, vector control alone is not cost-effective.

Some of the key questions and challenges in Aedes mosquito control today include:

– What are the best control methods available today?
– What tools are most effective to measure the impact of vector control on disease incidence?
– How should clinical studies be designed to assess the efficacy of vector control?

To answer these questions, regular workshops on Aedes aegypti control are organized.

Workshops on vector control

– 2015: Developing a Research Agenda for Assessing Vector Control to Prevent Dengue
The 2015 workshop provided answers to some questions raised at the 2013 meeting. Participants agreed on the importance of using epidemiological rather than entomological outcomes for field trials, as well as the best design for clinical studies (randomized controlled trials). They concluded that indoor residual spraying associated with larva control has the most powerful impact on dengue incidence.

– 2013: A Critical Assessment of Vector Control for Dengue Prevention
This meeting brought together 30 of the world’s leading experts on Aedes aegypti control and provided a “state of the art” assessment of current and future vector control methods. It identified knowledge gaps to be addressed in order to accurately evaluate synergies between vaccination and vector control.

Vaccines

A yellow fever vaccine that has proven its effectiveness in protecting individuals and preventing outbreaks is available. The first dengue vaccine was recently licensed and two other dengue vaccines are currently in phase 3 efficacy trials.

Unexpected adverse events following vaccination by the first licensed dengue vaccine led WHO to recommend pre-vaccination screening for the dengue vaccine. For other Aedes-transmitted diseases, Zika or chikungunya, a vaccine is still lacking.

Workshops on vaccines

– 2019: Dengue pre-vaccination screening based on serostatus: rapid tests and implementation strategies
Experts discussed rapid diagnostic tests and pre-vaccination screening strategies for dengue vaccine implementation following SAGE’s April 2018 recommendations.
– 2016: Dengue Immune Correlates of Protection
This workshop aimed to generate consensus and further our understanding of the immune response to infection with the dengue virus to more accurately measure vaccine efficacy.
– 2015: Dengue Clinical Case Classification for Clinical Research
Standardized clinical case definitions are essential to compare interventions to ensure protection and to monitor the long-term safety and effectiveness of dengue vaccines.

Surveillance & Diagnostics

Disease surveillance today must not only detect outbreaks but also measure the impact of vaccine and vector control interventions. With a changing surveillance landscape and the new vaccines, methods must be developed to accurately assess the burden of disease and the impact of interventions.

Passive surveillance systems based on physician reporting and case counts have considerable limitations, including poor sensitivity caused by delays between case occurrence and reporting, under-reporting, and insufficient serological and virological diagnosis. More research is needed to develop better tools for surveillance for Aedes-transmitted diseases.

For dengue, WHO recently published a new toolkit to estimate the burden of disease.

Workshops on surveillance

– 2017: New and Innovative Approaches to Laboratory Diagnosis of Zika, Dengue and other Arboviruses
This workshop aimed to identify gaps in the laboratory diagnosis of arboviral infections, review the new technological innovations that may be available to fill those gaps and promote and develop mechanisms for accelerating the pathway from tool development to impact.
– 2014: Meeting on Dengue Surveillance: New Paradigms and Innovations
Standardized clinical case definitions are essential to compare interventions to ensure protection and to monitor the long-term safety and effectiveness of dengue vaccines.