Could a vaccine eventually wipe out all mosquito-borne diseases?
What do malaria, Zika virus, dengue fever and a dozen more diseases have in common? They are all spread by mosquito bites. In many parts of the world, the high-pitched whine that tells you a mosquito is close by is more than irritating – it is troubling. The number of people infected is staggering, with dengue fever and malaria affecting around 600 million people a year.
According to the World Health Organization (WHO), dengue is the most important mosquito-borne disease. Attempts to tackle the problem disease by disease have been problematic, as the genetic profile changes frequently and new viruses, such as Zika, suddenly appear.
Joint NIH/biotech approach
Any news about a vaccine that could prevent mosquitos spreading these diseases is eagerly taken up. We could now be a step closer, as the American National Institutes of Health (NIH) has joined with SEEK, a British biotech company, in a joint venture to test a vaccine that could both prevent disease spread and reduce the mosquito population.
The project is now moving to a phase one clinical trial for the vaccine. The preventative treatment, called AGS-v, has been in development for almost a decade and uses a technique that has been known about for some time but has proven difficult to implement effectively. This approach focuses not on the disease pathogens but on the mosquito’s saliva.
Saliva the key to a vaccine
SEEK has replicated four mosquito saliva proteins; when delivered as a vaccine, these proteins alert the human immune system to the presence of mosquito saliva. Next, they enable an immune response that differs from the usual reaction to a bite. It is specifically targeted at preventing the invading pathogens from establishing themselves and replicating – they die at the bite site, or at least this is the theory. SEEK has apparently carried out tests on rats, mice and dogs; however, human trials are quite different, often involving volunteers in medical studies that pay from clinical research organisations such as http://www.trials4us.co.uk/.
Understandably, the company is guarding its molecular data closely. The phase one trial will focus mainly on safety and it will be many years before the vaccine passes all its trials and begins to be used on the populations at risk from mosquito-borne diseases.