Keeping the eggs in the omelette

I feel like a pincushion.  I’ve had so many pre-emptive shots this season to ward off flu and pneumonia and such that I am thinking I might as well go ahead and get a tattoo.

When I was younger, I laughed at the flu and never got a shot.  In fact I laughed at the people who ran around getting the shots in the fall, and called them all sorts of effeminate names.  But for the past few years the flu decided to remind me that I am not 25 years old any more, so now I get the shots.

When I can get them, that is.  There always seems to be a shortage of vaccine when I need the shot, and I can tell you one reason.  Eggs.

Yep, you need about 2 eggs to make a single dose of flu vaccine, and the vaccine itself generally doesn’t cover all the possible ways you might get the flu anyway.  Plus, it takes about six months to crank up the amount of production needed for the general population, so if something new and slightly unexpected comes along, it’s hard to get the vaccine to people in time.

Eggs are used to make vaccine?  Yup.  It’s the traditional method.  Eleven days after fertilization the embryos are injected with live virus, which then incubates inside the fluid sac until it is harvested.  Obviously not a wonderful experience for the embryo, I’m guessing.  So, that means that you need millions of fertilized eggs to make the product, and it all seems rather difficult and messy to me.  And slow, which means that some people, like about 36,000 per year, could die from the disease.

But, Dr. Paul Roberts of the Virginia-Maryland Regional College of Veterinary Medicine is coming to the rescue.  Roberts has been experimenting with a different method of producing the vaccine, based on cell cultures.  His goal is to develop a faster way to produce vaccine which will also be more adaptable to changing mixes of flu variants that occur during a typical flu season.  To accomplish this, Roberts essentially makes the flu produce its own poison.

The way your body fights an invader, such as a flu virus, is to produce antibodies against it.  It’s sort of like tagging the invading cells with a little red flag, and then sending out other killer cells to wipe out anything with red flags.  Unfortunately, antibodies work best when they are very specific to a particular invader, but the flu doesn’t consist of just one flavor of threat.

Roberts is using new cell culture technology to coax infected cells to produce their own antidotes, so to speak.  He tags the envelope of the host cell containing the virus with proteins that will induce the body to make antibodies, and so when the virus emerges, or ‘buds’ from the host cell, it gets wrapped in the envelope, effectively painting itself with a big bullseye for the immune system.  The virus itself is killed and then it can be safely injected into the host (me, for example) where my own body will stimulate my immune system against it without my having to actually get the flu.  Later, when real flu bugs invade me because my office mate spent the last three days coughing and sneezing on me, I’ve already got my antibodies lying in ambush.

I love it when a plan comes together.

So, the point is that eventually this cell culture technique might replace the egg incubation technique, which means that vaccines could be produced more rapidly to address emerging health threats.

Plus, since you no longer need millions of eggs to produce vaccine, demand for eggs will go down, resulting in lower egg prices for consumers…well, we won’t go there.  I like to discuss topics that have predictable outcomes, like science.  Not economics.

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Filed under biotechnology, genetics, medical technology

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