Q: What is the Genetically Attenuated Parasite (GAP) vaccine?
Developed by Seattle BioMed’s Stefan Kappe, Ph.D., this promising genetically engineered whole parasite malaria vaccine candidate has proven 100 percent protective, 100 percent of the time in mouse studies. This approach to vaccine development – using a weakened form of the whole organism that causes a particular disease – has proven successful in eradicating smallpox, as well as controlling diseases such as flu and polio but has never been used for fighting human parasites. Through precise deletion of two key genes in the parasite, Kappe and his team have developed a live vaccine that gives protection and yields accurate, reproducible results over time.

Q: What makes this approach unique?
While other malaria vaccine candidates are being tested, Seattle BioMed’s vaccine is unique in two aspects: its use of a specifically weakened form of the whole organism and the use of genetic modification of the parasite. (The RTS,S vaccine, developed by GSK, is a sub-unit vaccine, using a portion of the whole organism. And, while using the whole organism, a Sanaria vaccine relies on irradiation vs. genetic delection.)

Q: What is the burden of malaria on the world?
For centuries, malaria has been one of the greatest health challenges in the world, making more than 500 million people sick and killing about of one million people annually and destroying – through premature death and disability – the equivalent of at least 35 million years of healthy, productive human life each year.

Q: When will the GAP vaccine go into human trials?
The safety phase (proving that the vaccine itself isn’t harmful) began in 2010 and we anticipate the challenge phase (when volunteers exposed to malaria will be given the vaccine to see if it can protect against infection) to begin in early 2011.

Q: When will results be announced?
In early 2011.

Q: Why is the trial of the GAP vaccine being held at Walter Reed Army Institute of Research (WRAIR) when Seattle BioMed is building its own Malaria Clinical Trials Center?
For historical and timing purposes. WRAIR has been a longtime partner in the development of the GAP vaccine and has proven success and safety in human challenge trials (and in fact is working with Seattle BioMed to develop our own MCTC). Subsequent trials could potentially take place at the center in Seattle.

Q: How many total volunteers will you need?
We anticipate around 32 total volunteers: six in the safety phase and 20 in the immunization/challenge phase with six control volunteers that have not received the vaccine. We are currently working with the FDA for approvals before moving forward with this.

Q: What happens if the vaccine doesn’t work?
Our highest priority is to test if this type of live-attenuated vaccine is safe in humans. We anticipate achieving protection but the level of protection is hard to predict. While we hope the vaccine will prove highly protective, it will likely need refinement. Further development of next-generation attenuated strains is in progress and these strains will move forward into clinical testing. The one thing we are confident in is that we will gain valuable new knowledge that can be useful in the fight against malaria.

Q: What if trials prove the vaccine is successful?
There’ll be further refinement of the vaccine, development of next-generation attenuated strains and more clinical testing. One priority is to achieve complete protection with low doses of the vaccine. We’d also need to develop robust manufacturing platforms to make the vaccine and seek partners for development and distribution.