Producing Flu Vaccines Will Be Faster And Cheaper, Thanks To MSU Technology

While studying new techniques to produce vaccines for Marek's disease, a common chicken disease that causes big losses for poultry producers, Paul Coussens, MSU professor of animal science and microbiology and molecular genetics, and his colleagues found a cell line that had intriguing potential for growing flu virus – a change from the fertilized chicken eggs that are now used to grow the virus strains for vaccines.

HepaLife Technologies Inc., a biotechnology company based in Vancouver, has licensed the technology from MSU and plans to produce cell culture-based flu vaccine.

"We want to proceed as quickly as possible," said Harmel Rayat, president of HepaLife. "There's no time to waste. Sooner or later the avian flu virus will be in North America. It's not if, it's when."

"The recent highly virulent avian flu cases in Asia and fears about a pandemic have highlighted the problems with traditional influenza vaccine production methods, particularly the length of time to produce a new vaccine and the amount of vaccine that can be produced on short notice," said Coussens, who also is the director of the MSU Center for Animal Functional Genomics.

Building on work done by graduate student Amin Abujoub and assistant professor David Reilly, Coussens and his collaborators found the cell line would grow almost every type of flu virus: avian, swine, equine and human. In cell culture-based vaccine production, scientists infect cells with flu strains. Then they grow the virus in large vats or bioreactors. The virus is killed and purified to make the vaccine.

Growing virus in cell culture could dramatically speed up vaccine production. For the past 50 years, flu vaccines have been made by injecting 11-day-old fertilized chicken eggs with a flu virus strain. The virus grows in the eggs and is then killed and purified to make the vaccine. Each egg is injected with only one virus strain (a typical flu vaccine contains three strains) and produces enough virus for one or two doses.

This means that huge numbers of fertilized chicken eggs are needed – 270 million or more – to produce a sufficient vaccine supply for the United States. The process is time consuming and inflexible because vaccine makers have to order eggs months ahead of time. If there are any problems with the eggs, such as infection by another virus, the entire lot of flu vaccine is lost. Plus, anyone with an egg allergy can't have the vaccine.

"By growing cell culture-based flu virus, the cost and the time needed to produce the vaccine will be much lower," Coussens said. "We'll also be able to produce much more vaccine in a smaller space. And the virus that is grown is more pure. People with allergies to eggs are likely to benefit the most because they'll be able to have flu shots without the threat of allergic complications."

Coussens' research is supported by the U.S. Department of Agriculture and the Michigan Agricultural Experiment Station.