Thursday, April 12, 2007
Insect-based flu vaccine shows promise as rival to hen egg method-(bird flu related)
CHICAGO --Genetically engineered flu vaccine made from yellow striped caterpillars instead of hen eggs has been shown for the first time to keep people from getting the flu, scientists say.
The results are preliminary but suggest the insect method could be a quicker, easier alternative to the lengthy, antiquated egg-based procedure now used and lead to a more rapid response to a pandemic, the study authors say.
The experimental vaccine used in a study of 451 adults during the 2004-05 flu season was designed to protect against three common influenza strains. Among participants who got a single high-dose injection, at least two-thirds had a strong immune response and none developed the flu that season.
More than half of those given a lower dose had a strong immune response and two got the flu. By contrast, seven patients who received a dummy vaccine got the flu.
Vaccine-related side effects were mostly mild and included pain at the injection site and headaches.
Larger studies are needed to confirm the results, but the findings suggest the caterpillar model could be a promising approach for preventing seasonal and pandemic flu, the authors said.
The research was funded by the vaccine's maker, Protein Sciences Corp. of Meriden, Conn. The company designed the study with lead author Dr. John Treanor, a flu vaccine specialist at the University of Rochester in Rochester, New York.
The vaccine has been tested before, but this is the first time we've seen protection using this approach, Treanor said.
The results appear in Wednesday's Journal of the American Medical Association.
The current method takes about nine months each year. It relies on hens laying millions of eggs. Live flu viruses injected into the eggs multiply, then the eggshells are broken, the viruses are inactivated and are treated to create vaccine.
The experimental method uses fall army worms, abundant caterpillars that are vulnerable to a bug virus. Scientists replace a gene from that virus with a flu virus gene, then inject it into the worm, where it makes more flu virus.
The process takes about a month less than the egg method and doesn't involve using live flu virus, which can infect workers during the production process, Treanor said.
The study is important and suggests that the insect method is a technology that's worth pursuing, said Dr. Tom Talbot, a Vanderbilt University vaccine expert who was not involved in the study.
The process appears to be less labor-intensive than egg-based manufacturing, and would be useful for people who are allergic to eggs, Talbot said. Only a small percentage of people have egg allergies, but that still amounts to probably hundreds of thousands of people who go unvaccinated, he said.
Safety and Immunogenicity of a Baculovirus-Expressed Hemagglutinin Influenza Vaccine
In this study, a trivalent rHA0 vaccine was safe and immunogenic in a healthy adult population. Preliminary evidence of protection against a drifted influenza A(H3N2) virus was obtained, but the sample size was small. Inclusion of a neuraminidase component did not appear to be required for protection.
A high priority in vaccine research is the development of influenza vaccines that do not use embryonated eggs as the substrate for vaccine production.
To determine the dose-related safety, immunogenicity, and protective efficacy of an experimental trivalent influenza virus hemagglutinin (rHA0) vaccine produced in insect cells using recombinant baculoviruses.
Design, Setting, and Participants
Randomized, double-blind, placebo-controlled clinical trial at 3 US academic medical centers during the 2004-2005 influenza season among 460 healthy adults without high-risk indications for influenza vaccine.
Participants were randomly assigned to receive a single injection of saline placebo (n = 154); 75 µg of an rHA0 vaccine containing 15 µg of hemagglutinin from influenza A/New Caledonia/20/99(H1N1) and influenza B/Jiangsu/10/03 virus and 45 µg of hemagglutinin from influenza A/Wyoming/3/03(H3N2) virus (n = 153); or 135 µg of rHA0 containing 45 µg of hemagglutinin each from all 3 components (n = 153). Serum samples were taken before and 30 days following immunization.
Main Outcome Measures
Primary safety end points were the rates and severity of solicited and unsolicited adverse events. Primary immunogenicity end points were the rates of 4-fold or greater increases in serum hemagglutinin inhibition antibody to each of the 3 vaccine strains before and 28 days after inoculation. The prespecified primary efficacy end point was culture-documented influenza illness, defined as development of influenza-like illness associated with influenza virus on a nasopharyngeal swab.
Rates of local and systemic adverse effects were low, and the rates of systemic adverse effects were not different in either vaccine group than in the placebo group. Hemagglutinin inhibition antibody responses to the H1 component were seen in 3% of placebo, 51% of 75-µg vaccine, and 67% of 135-µg vaccine recipients, while responses to B were seen in 4% of placebo, 65% of 75-µg vaccine, and 92% of 135-µg vaccine recipients. Responses to the H3 component occurred in 11% of placebo, 81% of 75-µg vaccine, and 77% of 135-µg vaccine recipients. Influenza infections in the study population were due to influenza B and A(H3N2), and influenza A infections were A/California/7/2004-like viruses, an antigenically drifted strain. Seven cases of culture-confirmed CDC-defined influenza-like illness occurred in 153 placebo recipients (4.6%) compared with 2 cases (1.3%) in 150 recipients of 75 µg of vaccine, and 0 cases in recipients of 135 µg of vaccine.
Trial Registration clinicaltrials.gov Identifier: NCT00328107
Then they've had some recent financial difficulties but our govt helped them remain solvent HHS must be confident about the end product, if they awarded that kind of money( aprox. 150 million total) to an almost bankrupt company.
A small biotechnology company facing possible bankruptcy and liquidation has been awarded a $35 million federal contract to develop a faster way to make vaccines for pandemic influenza.
The award of the contract to the Protein Sciences Corporation of Meriden, Conn., was announced on Tuesday by the Department of Health and Human Services. But only a day earlier, creditors filed a petition in federal bankruptcy court in Wilmington, Del., seeking to force Protein Sciences into bankruptcy and liquidation, saying they were owed $11.7 million.
Almost all of that money is owed to Emergent BioSolutions, a vaccine company in Rockville, Md., that lent Protein Sciences $10 million last year in advance of the pending acquisition of virtually all the assets of Protein Sciences by Emergent. The acquisition deal fell apart, and Emergent sued Protein Sciences and its top executives, accusing them of fraud and breach of agreements.
The series of events raises questions about whether the government is entrusting part of the nation's influenza defense to a financially shaky or untrustworthy company. Robin Robinson, director of the branch of Health and Human Services that will administer the contract, said the government had spent months doing two very thorough financial audits of Protein Sciences. It was determined that they were healthy enough to go forward with development of this vaccine, he said.
The company, which is privately held, has already applied to the Food and Drug Administration for approval of a seasonal flu vaccine. And last week, Mr. Adams said, the company made its first 100,000 doses of a vaccine against the new swine flu.
The federal contract will help Protein Sciences develop its technology and obtain FDA approval. It can be extended up to five years for a total cost of $147 million.
If the technology is proved safe and effective and is licensed by the FDA, the contract calls for Protein Sciences to establish domestic manufacturing capacity, to provide a finished vaccine within 12 weeks of the onset of a pandemic and to produce at least 50 million doses of a pandemic flu vaccine within six months.
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