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The current outbreak of the H1N1 influenza strain is exactly the kind of situation the vaccine company Novavax (Rockville, MD) has been preparing for over the last three years.
The current outbreak of the H1N1 influenza strain is exactly the kind of situation the vaccine company Novavax (Rockville, MD) has been preparing for over the last three years. The only difficulty is the outbreak arose a little earlier than hoped, because the company has not quite finished testing its technology.
Nonetheless, the company’s President and Chief Executive Officer Rahul Singhvi, ScD, says the company is ready to play its part. “We hope to be a part of the overall solution for the government, to help in this moment of need,” he said. “We are ready to say ‘here’s what we have done and here’s what we can do, if you need us.’”
And what the company can do is prepare an influenza vaccine in only 10–12 weeks from the identification of a new viral strain after the Centers for Disease Control and Prevention (CDC) released the genetic code of the infectious virus strain. That compares to approximately 20–24 weeks for traditional egg-based methods. For more details, see the January 2009 supplement to BioPharm International.
Novavax produces its vaccines by using recombinant baculovirus vector and insect cell culture to produce proteins specific to the emerging influenza strain that then self-assemble into an enveloped, non-infectious particle (virus-like particle or VLP), similar to that used in Merck’s vaccine against human papillomavirus. The system’s high yields make it possible to produce significant quantities of vaccine using only 1,000–2,000-L disposable bioreactors, which significantly reduces the time and cost of setting up and validating a new production facility.
The challenge is that the company has not yet completed clinical testing of its influenza vaccines. Results of Phase 1/2a clinical tests of seasonal and H5N1 pandemic vaccines have been positive, however. In addition, results from a preclinical study published in March in collaboration with the CDC showed that mice that received intranasal immunizations with VLPs generated from structural proteins of the 1918 H1N1 virus were largely protected against both the 1918 virus and the H5N1 virus.
Singhvi said he did not yet know exactly what clinical testing would be required by the US Food and Drug Administration in an emergency situation like this. “It will probably not be a one-size-fits-all situation,” he said, noting that testing requirements for his company’s vaccine are likely to be a greater than those for vaccines produced by firms that have seasonal influenza vaccines on the market.
Novavax finished construction of its manufacturing facility in January, but scale-up efforts are not yet completed. Even using their current set of 100-L bioreactors, however, Singhvi says the company would be capable of producing hundreds of thousands of doses per week of a vaccine for H1N1 (assuming 15 mcg/dose). “If we could do scale-up work in parallel, we could quickly get up to producing millions of doses a week,” he said.
The vaccine would also require formulation, but Singhvi is confident that could be done fairly quickly. “We have not yet seen much variation in the formulations required from one VLP to another,” he said, which should facilitate formulation. The time need to conduct formulation work is included in the 10–12 time period to prepare the vaccine.