Scientists Develop Faster Process
To Produce Vaccine for Bird Flu
By BETSY MCKAY
Staff Reporter of THE WALL STREET JOURNAL
February 2, 2006; Page D2
Scientists at the Centers for Disease Control and Prevention and Purdue University have developed a technology that they say could make a vaccine for a pandemic strain of avian influenza more effective and easier to manufacture than a vaccine produced with currently available methods.
The research, being published today in the online version of the journal the Lancet, is the latest effort under way by scientists world-wide to modernize the typically time-consuming and antiquated process used to produce flu vaccines.
Public-health officials have warned that continuing to rely on the months-long process of producing vaccine in chicken eggs could leave much of the world defenseless in a pandemic because the disease could have spread widely by the time a vaccine was ready. Manufacturers wouldn't be able to make enough to inoculate the global population because there aren't enough production facilities, and about four billion eggs would be needed, public-health officials say. Tests of avian-flu vaccines produced using eggs have shown that people require high doses of vaccine to be sufficiently protected.
Experts said new technologies like the one detailed in the Lancet are promising. But they haven't been tested on humans, and it could be years before they are commercialized. The vaccine created by the CDC and Purdue scientists was tested using mice, while a similar study published by researchers at the University of Pittsburgh, with collaborators from the CDC, was conducted on chickens and mice. That study appears in this month's issue of the Journal of Virology.
"This is an important incremental advance," Anthony Fauci, director of the National Institute of Allergy and Infectious Disease, said of the latest study. The NIAID partially funded the CDC and Purdue research. The "proof of the pudding" is clinical trials to see if the vaccine generates the same immunity in humans that it did in mice, he added.
In the CDC and Purdue study as well as the study at the University of Pittsburgh, scientists said they had genetically engineered a common-cold virus to produce an important component of the avian-flu virus. The CDC and Purdue scientists then tested the vaccine on mice by immunizing them twice and then infecting them with lethal doses of the H5N1 virus, which has infected at least 160 people and killed 85 world-wide, according to the World Health Organization. The University of Pittsburgh team said their vaccine offered full protection against the H5N1 virus in both chickens and mice.
The new vaccine is easier to produce because it can be grown in cells that are widely available in a laboratory and doesn't require eggs, said Suresh Mittal, professor of veterinary pathobiology at Purdue and an author of the Lancet study. Using common-cold viruses would make mass production of a vaccine easier because pharmaceutical companies grow them in large amounts, he said.
The CDC and Purdue researchers said their vaccine could be more potent and versatile in humans than traditionally produced vaccines because it generated a stronger immune response and offered protection against several strains of the H5N1 virus in animal tests, not just the strain now circulating. The University of Pittsburgh researchers reported similar findings.
Suryaprakash Sambhara, a CDC scientist and co-author of the latest study, said the new vaccine's versatility would made it a good candidate for stockpiles to protect people against future outbreaks of avian flu.
Andrea Gambotto, assistant professor of surgery and infectious disease at the University of Pittsburgh and lead author of that institution's study, said that his team hopes to begin clinical trials in four to six months. Dr. Gambotto said his team is also exploring whether it can make a cost-effective avian flu vaccine for poultry. The CDC said it will start making plans for clinical trials as early as next week. |
