Earlier this week, the HHS doubled down on new vaccine technology. The government granted Maryland-based Novavax a contract worth up to $179.1 million, while Cranbury, NJ's VaxInnate picked up a potential $196 million deal. Both companies are developing new approaches to seasonal and pandemic influenza that could help the country move away from slower, less reliable egg-based manufacturing.
The HHS has taken a systematic, portfolio-like approach to funding vaccine development in the U.S. In the mid-2000s, the federal government moved to secure egg-based vaccine manufacturing, putting its money into established technology to guarantee the vaccine supply. Then it started the next round of funding for cell culture production, and in the latest round, it has funded recombinant cell culture based technology. Three awards have been granted in this area, Novavax CEO Rahul Singhvi (pictured) explained in an interview with FierceVaccines. The first was granted to Protein Sciences in 2009; the company has yet to win approval for its seasonal flu vaccine, FluBlok, which was made by inserting flu genes into an insect virus and growing it in caterpillar ovary cells. Novavax and VaxInnate account for the other two contracts.
Novavax's influenza and pandemic influenza programs are based on the same recombinant virus-like particle (VLP) technology used to create the Gardasil and Cervarix HPV vaccines. "VLPs mimic the virus and, look like the virus, but they are created by expressing only a fraction of the genes needed to assemble the entire virus. It's an empty shell and doesn't have any RNA or proteins of the virus, and therefore doesn't have any replication machinery," explains Singhvi. But the body's immune system recognizes VLPs as a virus and builds up an immunity to the disease.
Traditional chicken egg-based manufacturing requires developers to actually grow the virus in eggs, kill it with chemicals and then use bits of the killed virus to make that year's vaccine. A number of companies are working on a new cell-based approach that promises to cut time off the development process. But as Singhvi explains, companies taking this approach are simply changing the growth substrate for the virus. The viruses to create the vaccine are still grown, but in mammalian cells rather than a chicken egg. "Our approach does not require growing the influenza virus. We construct the VLPs through recombinant DNA techniques." He points out that Novavax's VLP technology platform has already been validated by the approval of Gardasil, which mitigates the risks of applying this a new technology for flu vaccines. "Other new technologies being employed for flu vaccines don't have that kind of validation," he says. "The inherent risk of getting a prophylactic vaccine on the market is very high. When you use novel but proven technologies that have gone through regulatory scrutiny, it's a differentiating feature."
Novavax has completed five Phase II trials of VLP technology based influenza vaccines. The HHS funding will provide support for three clinical trials using its pandemic influenza vaccine candidate with adjuvants. The funding will also bankroll a Phase II dose-ranging trial and a Phase III registration trial of Novavax's seasonal influenza shot. Finally, the contract supports the development of a manufacturing facility to produce 50 million doses of vaccine within six months.
Last year, the Advisory Committee on Immunization Practices, a policy group that makes recommendations on vaccines, advised that a flu shot be given to everyone in the U.S. "That recommendation instantaneously increased market size by two-fold. It's policymakers that are making a big impact on the market," says Singhvi.