Speaker: Dr Marie- Paule Kieny
WHO Assistant Director- General for Health Systems and Innovation
9 March Press Briefing
The WHO meeting that just finished provided the first global platform for scientists working on Zika virology and immunology, clinicians, product developers, regulators, funders and policy experts to take stock of the R&D pipeline, identify knowledge gaps and agree on a forward plan to accelerate product development and evaluation
The R&D community has responded vigorously to the need for Zika medical products and innovative vector control measures and the pipeline of candidate products has expanded rapidly.
Over 60 groups are currently involved in Zika R&D – approximately half of those working on diagnostic tests
Major advances compared to the Ebola product R&D response is the speed with which data is being shared – for example, the WHO Bulletin is posting on its website articles related to Zika research while the peer-review process is ongoing.
Key knowledge gaps that were identified during the meeting included:
the need to better understand the mosquito dynamics and the role of various species in virus dissemination the need for reliable animal models which would allow evaluation of medical interventions understanding how prior exposure to related viruses, such as dengue, would impact, if at all, the immune response to a Zika vaccine
Given these open questions, vaccine development is still at an early stage and the most advanced candidates are still months away from entering early human clinical trials. It is therefore possible that vaccines may come too late for the current Latin American outbreak, but the development of a vaccine remains an imperative for regions likely to be affected by Zika in the foreseeable future – in particular vaccines suitable for pregnant women and women of child bearing age.
We do know that the development of a Zika vaccine is technologically feasible based on the experience with licensed vaccines against other flaviviruses such as Japanese encephalitis, tick-borne encephalitis and dengue.
Zika diagnostic development is at a more advanced stage, and some tests have already obtained authorization in some countries.
However, additional, independent validation of these and future tests are urgently needed. The WHO Emergency Use, Assessment and Listing procedure provides a mechanism to rapidly qualify diagnostic tests, so we continue to urge developers to submit their products to WHO .
The meeting also encouraged the development and evaluation of products which enable differential diagnosis of Zika and related viruses such as Dengue and Chikunginya viruses – so called multiplex tests.
A key need identified at the meeting was for reference reagents and standards – these are measurement standards necessary for the development of various products, in particular diagnostics and vaccines. Producing such reference reagents and standards is dependent on timely sharing of biological Zika samples. The meeting heard that an international collaborative study to evaluate a candidate reference reagent may start as early as April.
On vector control, what we heard from experts at the consultation is that there is a clear lack of evidence that any classical vector control intervention has had any significant impact on dengue transmission. This is important because we must be sure that we invest in interventions that work. A target product profile is being developed for novel tools, such as Wolbachia, Oxitec and irradiated mosquitoes, as well as rigorous methods to evaluate these tools.
An emergency meeting of the WHO Vector Control Advisory Group will take place next week to discuss the best way forward.
Finally a word on regulation. Regulatory challenges around the use of experimental technologies in public health emergencies are many.
Major regulatory agencies – ANVISA, the Brazilian authority, the US FDA and the European Medicines Agency – committed to prioritizing the expedited evaluation of Zika products and will proactively reach out to developers of lead products to provide advice on regulatory issues
WHO will likewise lend support to scientists, developers, regulators and public health officials wishing to advance any new products that emerge and will foster greater collaboration and knowledge sharing among countries, also leveraging from lessons learned during the Ebola experience.
WHO media Team