By Julie Steenhuysen
CHICAGO (Reuters) - Fighting the flu may soon get easier.
As early as next year, more modern and more effective vaccines will hit the market, thanks to investments by the U.S. government and pharmaceutical companies. And even bigger scientific advances are expected in the next decade, including a "universal" flu vaccine given every five to 10 years that would fight many strains of a virus, making annual shots all but obsolete.
Experts say it could take eight to 10 more years of testing before a universal flu vaccine would be ready. Meanwhile, they expect advances that could still incrementally improve the level of protection vaccines offer and shorten manufacturing times.
In the last 12 months, the U.S. Food and Drug Administration has approved two new seasonal flu vaccines that protect against four predominant strains of flu instead of three. One is a shot made by GlaxoSmithKline and the other is a nasal spray made by AstraZeneca.
In late November, the FDA approved Novartis' new flu vaccine grown in cultures of dog kidney cells instead of the conventional chicken eggs, a faster and more reliable manufacturing process that could help build stockpiles in the event of a pandemic.
And this past week, the FDA green-lighted the first gene-based flu vaccine by Protein Sciences Corp, which uses genetic engineering to grow portions of the virus in insect cells. "This means there are going to be more manufacturers and more types of vaccine available in future flu seasons," FDA Commissioner Dr. Margaret Hamburg said in a teleconference on Friday.
Flu vaccines have not been high-revenue generators for major pharmaceutical companies compared with big-selling drugs for diabetes, heart disease, rheumatoid arthritis and cancer. Vaccines are expensive to make, and the flu can mutate significantly from season to season. In a mild flu season, companies can be left with millions of unsold doses if the flu season is mild.
Interest in vaccines spiked after a particularly deadly strain of bird flu known as H5N1 re-emerged in 2003, raising the threat of a global pandemic that could kill millions. At the time, there were just two vaccine manufacturers located on U.S. soil.
A year later, U.S. flu vaccine supplies were devastated by contamination at a plant in Liverpool, England. That helped underscore the need for America to have its own manufacturing capabilities, said Robin Robinson, director of the U.S. Biomedical Advanced Research and Development Authority, or BARDA, a part of the U.S. Department of Health and Human Services (HHS).
Part of the fear was that in a pandemic, countries might be tempted to commandeer all flu vaccines made within their borders, leaving the U.S. exposed. "We needed to develop new vaccines using modern technologies that would make not only more vaccine available sooner, but also make it more effective," Robinson said.
A FASTER, SAFER PROCESS
Current flu vaccines are mostly grown in fertilized chicken eggs using a 60-year-old method that requires hundreds of millions of eggs. The technique can take up to six months and is an arduous process, prone to manufacturing problems.
First, experts at the World Health Organization and the FDA have to predict which flu strains will be causing most of the illness in the coming season. Then, they make seed strains of the flu from people who are infected, which must then be manipulated into a form that will grow in live chicken eggs.
At every step there is risk for contamination. In some years certain flu strains have refused to grow readily in eggs, and the end product only protects 50 to 70 percent of people who get it. The vaccine for the current flu season is estimated to have a 62 percent effectiveness rate.
With newer methods, companies can skip the egg portion of the process altogether.
In 2006, HHS provided more than $1 billion in contracts to six manufacturers to develop cell-based flu vaccine technology in the United States. Although its use in flu vaccines is new, cell-based vaccine technology has been around for years, offering a faster, more reliable alternative to egg culture.
In 2009, spurred by difficulties in growing vaccine for the H1N1 swine flu pandemic, HHS provided Novartis with nearly $500 million to build the first U.S. facility capable of producing cell-based vaccine for seasonal and pandemic flu in the United States. Novartis picked up the rest of the estimated $1 billion price tag.
The following year, Novartis opened a plant in Holly Springs, North Carolina, which was approved to make pandemic doses of H5N1 bird flu vaccine in late 2011. Last November, Novartis' Flucelvax became the first cell-based flu vaccine to win U.S. regulatory approval.
Novartis made a limited supply of the new vaccine available for this flu season, and more will be sold once the plant is licensed for seasonal flu production.
Baxter International Inc, one of the initial six companies to win an HHS grant, is almost ready to apply for approval in the United States for its cell-based flu vaccine Preflucel, which is already approved in 13 European countries.
TINKERING WITH GENES
The United States has also backed new approaches that use genes or proteins to make vaccine.
In 2009, HHS' five-year, $147 million investment helped bail out then-struggling Protein Sciences, and the tiny biotech has now produced the first gene-based vaccine to win FDA approval.
"The new technology offers the potential for faster start-up of the vaccine manufacturing process in the event of a pandemic, because it is not dependent on an egg supply or on availability of the influenza virus," Dr. Karen Midthun, director of the FDA's Center for Biologics Evaluation and Research, said in announcing the approval on Wednesday.
Protein Sciences says its vaccine, called FluBlok, has three times the active ingredient traditional vaccines have and contains no preservatives, which some people object to. It can also sidestep some of the risk of infection associated with vaccines grown in eggs.
Instead of using the whole virus, Protein Sciences makes its vaccine using a single flu gene known to evoke a strong immune response. The company places this into a harmless insect virus called baculovirus. The virus grows inside insect cells, which are then purified to become a basic part of a human vaccine. Continued...