By Tom Still
MADISON – It’s a new twist on an age-old question: What came first, the chicken or the fertilized egg?
So far as flu vaccine production is concerned, the answer is definitely the egg. Millions of contaminant-free, fertilized eggs are needed each year to produce vaccines against predicted strains of influenza. Absent sufficient numbers of “clean” fertilized eggs, there is no current way to produce the flu vaccines public health experts believe we’re most likely to need.
In fact, it’s hard enough to produce vaccines even with mounds of specially tailored eggs. Growing flu viruses inside fertilized chicken eggs, then breaking out the key proteins that provoke an immune response, is the start of a six-month purification, testing and packaging process. That means vaccine-makers are counting their eggs now in order to prepare for strains likely to hit this fall and winter.
Why not divert fertilized eggs to produce a swine flu vaccine? It’s not an easy choice. Between 250,000 and 500,000 people die each year worldwide from what might be described as “common” flu strains, so diverting production to produce a swine flu vaccine might leave millions of people dangerously exposed to influenza strains they’re actually much more likely to catch. Meanwhile, the current swine flu strain could mutate its way out of existence.
“The problem is that egg-based production technology is about 50 years old,” said Paul Radspinner, president and CEO of Madison-based FluGen, one of several Wisconsin companies engaged in the war against flu. “It’s cumbersome, expensive and open to contamination. We’ve got to find faster and better ways.”
FluGen is working on one answer. It is among a number of companies worldwide working to develop a safe, fast and reliable way to grow vaccine viruses inside vats of cells versus fertilized chicken eggs.
Different companies are working on different processes. At least one company is using insect cells; others are using animal cells. Radspinner won’t say what types of cells FluGen is using in its research, other than to say they are “well-characterized,” meaning well-understood by scientists.
Cell-based vaccine production has not been approved in the United States, but public and private investments in possible solutions have been intense. More than $1 billion has been spent by the federal government alone in the last five years to speed cell-based vaccine production, and one manufacturer (Novartis) is building a cell culture vaccine factory in North Carolina. But that factory won’t be ready for at least a year.
FluGen’s chief scientist is Yoshihiro Kawaoka, who is working with a sample of swine flu virus in a $12.5 million biosafety lab called the Institute for Influenza Virus Research. He’s a prominent example of a scientist who was retained by the UW-Madison after another university tried to lure him away.
Another Wisconsin company engaged in the “flu wars” is Waukesha-based Prodesse. It has developed a test that has successfully detected swine flu in specimens that were not revealed by other rapid tests.
Several clinical labs in the United States used Prodesse Inc.’s test, called ProFlu+, to re-analyze samples that were negative for swine flu, the company said in a news release.
“ProFlu+ sequences are a nearly perfect match to every known swine flu sequence, meaning that users can have high confidence that swine flu will be detected by ProFlu+,” the company said.
Producing vaccines to protect against flu is a sophisticated guessing game, but better technology is reducing risk and improving the odds of getting it right. It may be years before science can produce flu vaccines virtually on demand, but when that day arrives, some of the important research may well have been done in Wisconsin.
Still is president of the Wisconsin Technology Council. He is the former associate editor of the Wisconsin State Journal in Madison.