Canadian Business Article - This month's issueBiotech
Plant-based flu vaccines
New plant technologies are faster and cheaper than the old egg–based systems.
By Angelina Chapin
When the H1N1 pandemic was officially declared on April 24 of lastyear, the first dose took six months to make, meaning no one was treatedduring the first infection wave that summer. According to the PublicHealth Agency of Canada, 426 Canadians died from the influenza, and only41% of the population was ultimately vaccinated, far short of thenational target of 70%. Thanks to a $21-million grant from the U.S.Department of Defence, a Quebec biotech company thinks it has found asolution in plant-based vaccines — a technology that reduces theproduction time for vaccines by almost two-thirds.
The central bottleneck in producing flu vaccine is the 50-year-oldmethod of injecting the virus into the amniotic fluid of a fertilizedhen's egg. The process involves waiting for the virus from the WorldHealth Organization (WHO), finding a strain that can grow well in eggsand making sure the eggs are at the proper level of maturity beforeincubating them. In the case of H1N1, it took four months before vaccineproduction could start.
Over at Medicago's research facility in Quebec City, the company wasready to start making H1N1 vaccine in two weeks after using a muchsimpler process called recombinant DNA technology. Medicago has patentedthe process that enabled them to download the genetic sequence for thevirus from the Internet, rather than from the strain itself, and clone astrand of DNA to incubate within their plants. In under a month, theyproduced a vial of H1N1 vaccine.
In the event of another pandemic, "we could be a first-response solution," says CEO Andy Sheldon.
He says many aspects of the plant-based process are easier, whichinvolves soaking nicotine-free tobacco leaves from Australia in asolution containing the virus's DNA and incubating them in a greenhouse.Unlike fertilized hens' eggs, which will hatch if they aren't used, theleaves are easy to keep in stock. Leaves are also more efficient, eachproducing 100 vaccinations compared with the two to five doses from eachegg. Then there's cost: Sheldon says setting up a facility to produceplant-based vaccines costs less than a tenth of that by othertechnologies, including cell-based vaccines being used in Europeanmarkets.
The Pentagon funding will pay for a new 85,000-square-foot facilityin Durham, N.C., and it means Medicago will have the space and resourcesto move on to Phase 2 of the testing process — seeing if they canproduce 10 million vaccinations per month. This could have a significanteffect on preventing the spread of a pandemic, considering thataccording to StatsCan, during the H1N1 outbreak only 11.6 million peoplewere vaccinated.
Scott Halperin, director of the Clinical Trials Research Center(CTRC), a research centre at Dalhousie University that worked with thePublic Health Agency during the pandemic, says the only reason egg-basedvaccines are still around is that the infrastructure is established."Egg-based vaccines will disappear for the long term," he says. "Forshort and medium term, they'll be there as the main workhorse as gradualtechnologies scale up, because the transition cost is difficult forfunders."
The Canadian and U.S. governments have taken different strategies onvaccinations. Halperin says for the past 10 years, Canada has investedheavily in GlaxoKlineSmith, an international pharmaceutical company thatproduces egg-based vaccines, to make sure they have the capability toimmunize all Canadians.
The U.S. government has never prioritized the infrastructure tovaccinate all Americans, but since the H1N1 outbreak, it has decided toput its money toward funding the most advanced technology out there tocombat pandemics. Sheldon says this means that in case of a moderate tosevere pandemic breaking out, the U.S. would have priority access toMedicago's plant-based vaccines. He says the Canadian government isrenegotiating their pandemic plan in 2011 and would like them to investin a production facility for Medicago so Canadians could also benefitfrom the technology.
Halperin says though he would welcome a Canadian facility producingplant-based vaccines, the technology is still in its early stages ofdevelopment. "You can make the best vaccine in world that's 100%effective and perfectly safe," he says. "But for something to be usable,you have to be able to make hundreds of thousands or millions of doses,or it won't have an effect on the population."