STEVE INSKEEP, Host:
For many Americans, the most pressing health care question at the moment is how to get the swine flu vaccine. A big reason for the vaccine shortage has to do with how it's made. It's grown in chicken eggs that have been infected with a modified form of the H1N1 virus. That process takes months. And it's taken years to find an alternative. Last week an experimental vaccine reached the Food and Drug Administration for evaluation.
NPR's Joanne Silberner reports on the prospects.
JOANNE SILBERNER: At a press conference recently, Thomas Frieden, head of the Centers For Disease Control and Prevention said there's a problem with the system that relies on viruses growing in eggs.
THOMAS FRIEDEN: Even if you yell at them, they don't grow faster.
SILBERNER: According to Bill Hall, a spokesperson for the Department of Health and Human Services, the government has spent nearly $2 billion in the last five years on developing a way to make vaccines without using eggs.
The goal is simple: come up with a piece of the flu virus coat, a protein that your immune system will learn to recognize to foreign, get vaccinated with it, then when someone with flu coughs on you, your immune system is already primed to fight off the virus.
Coming up with a protein involves some pretty sophisticated science, says Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, which has funded much of the research. One approach starts with the genetic material of the flu virus, naked DNA.
ANTHONY FAUCI: You take the genes of that and you then inject the DNA directly into the muscle of the vaccine recipient.
SILBERNER: You just need a segment of the DNA. Your own cells pick up the segment and manufacture a protein. No yelling at eggs and no issues with egg allergies.
DNA: inserting a piece of the virus's DNA into a harmless virus that grows quickly and well - not in your body but in cell cultures - insect cells. Again, Anthony Fauci.
FAUCI: Since that virus grows in those insect cells, as it grows it starts to essentially spit out large amounts of the protein that you're interested in. You then take that protein, you harvest it from the cell culture, you purify it and there's your vaccine.
SILBERNER: It takes les than two months, as opposed to the five months or so it takes to develop and grow a vaccine in eggs. And there are variations on this approach. Hooking the virus's DNA into a harmless virus for direct use as the vaccine; or foregoing genetics entirely, and just building a protein out of chemicals in the lab.
All of this new technology to speed up vaccine manufacture actually takes a lot of time, says Robert Couch, a vaccine expert with the Baylor College of Medicine.
ROBERT COUCH: Nothing is done very rapidly in these systems, because so much time is required for developing, for evaluating safety, for doing the manufacturing systems that are optimal.
SILBERNER: These are new technologies and it's likely to take regulatory agencies a long time to be assured they're safe. Couch has been advising a company called Protein Sciences, which is furthest along towards a new flu vaccine. It's using the insect cell technology and has tested its product on more than a thousand people.
Last week, an FDA advisory committee gave it mixed reviews, saying the vaccine appears to be effective in 18- to 49-year-olds but needs more safety testing. Company head Daniel Adams says he'll press forward.
Joanne Silberner, NPR News.
INSKEEP: Here's another story we're following on this Thanksgiving Day: It is a workday in China, and Chinese officials have announced that they intend to sharply cut carbon emissions. The nation, sometimes known as the world's biggest polluter, is taking steps to cut back, and China now says it wants to fight global warming and also make its economy drastically more efficient.
Chinese officials have set an ambitious goal - it's not clear how they'll reach it - but an ambitious goal that, by the year 2020, they want to find a way to use around 40 percent less energy for the same amount of economic activity. The U.S. Congress is still debating what steps, if any, Americans will take.
(SOUNDBITE OF MUSIC)
INSKEEP: You're listening to MORNING EDITION from NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.