The threat of H1N1 swine flu appears to be easing, but the virus could come roaring back later in the year, and experts are now debating whether to produce a vaccine against pandemic influenza. A key problem is that almost all the vaccine against influenza in the world is produced using chicken eggs, and the production capacity is very limited. Many manufacturers are working on alternatives to the outdated technology for the production of vaccines, but those who will play a small role in the world should best be hit by an influenza pandemic this year, the World Health Organization vaccine expert Marie-Paule Kieny, told a news conference today. They could make a difference on the road, however.
Almost all vaccines against seasonal flu is made using a 50-year clumsy process, in which companies adapt the virus to multiply in chicken eggs, Growing the virus, then break open eggs and purify the key antigens which are needed to make a vaccine, hemagglutinin and neuraminidase molecules coming out of the surface of the virus. Overall, the process takes longer than 5 months. This is also how the vast majority of a vaccine against the pandemic would be made.
Most vaccine manufacturers are working on similar vaccines are grown in mammalian cells rather than eggs. This has several advantages: Manufacturers are less dependent on the supply of chicken that eggs that is difficult to increase quickly and may become vulnerable during the avian influenza outbreaks and could shave 10 weeks of leave of 22 weeks for necessary make a vaccine using eggs. It would also produce a vaccine that is safe for people allergic to eggs.
But much more convenient and cleaner, cell based vaccines do not promise a major boost in production capacity. Moreover, the success of the technique has been slow in coming, despite more than $ 1.5 billion in the Department of Health and Human Services US contracts to several companies to finance vaccines for clinical trials cells and intensify production. Novartis is the only company that began building a cell-based vaccine facility in the United States (North Carolina) with the help of a $ 487 million HHS contract awarded in January. It should be operational by 2012. No vaccine based on cells has not yet been approved in the United States, partly because obtaining regulatory approval is complicated.
In Europe, at least three companies licensed a vaccine based on cells, but none have actually started producing far. Solvay is building a plant in a small town outside Amsterdam several years ago, but technical problems delayed the start of production. "In terms of quantity, worldwide, [cell-based vaccines] only represent a small amount of the total," Kieney said today.
Some alternatives might be faster to scale up. Is furthest along Protein Sciences Corp. Meriden, Connecticut, which is a vaccine against influenza by infecting caterpillar cells with a baculovirus carrying the hemagluttinin gene. The company has completed clinical trials at an advanced stage for its vaccine against seasonal flu and is awaiting the approval of the US Food and Drug Administration this year; he plans to make a vaccine against swine flu in five weeks at its pilot plant production, says CEO Daniel Adams. This vaccine could be produced in many plants worldwide for the production of pharmaceutical proteins, which could allow production of enough vaccine for between $ 3 billion and 6 billion people in three months, said David Fedson, a retired officer of drug company living in France.
other recombinant vaccines that could really lead to an explosion of production capacity are further away. VaxInnate, a company in Cranbury, New Jersey, is developing a vaccine against the flu is in E. coli , which requires much less volume for the production of animal cells. It connects a portion of the hemagluttinin protein flagellin of bacteria to increase the response of immune cells. CEO Alan Shaw says the company could make enough doses for the state of New Jersey in a reactor the size of the gas tank on a barbecue.
"It is a much simpler production system," says expert vaccine against influenza John Treanor of the University of Rochester in upstate New York. Treanor notes, however, that this first new approach to stimulating immunity will require extensive clinical trials to establish that it is safe and works.
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