Better by design: Engineering flu vaccinesMarch 18, 2009A new computerized method of testing could help world health officials better identify flu vaccines that are effective against multiple strains of the disease. Rice University scientists who created the method say tests of data from bird flu and seasonal flu outbreaks suggest their method can better gauge the efficacy of proposed vaccines than can tests used today. Rice's Michael Deem, the lead scientist on the project, will present the group's results March 19 at the American Physical Society's 2009 meeting in Pittsburgh. The results are also slated to appear in the forthcoming book "Influenza: Molecular Virology" from Horizon Scientific Press. Avian flu, or bird flu, is a particularly deadly type of flu that's transmitted from birds to humans. It hasn't yet evolved into a form that can be transmitted readily between humans, but scientists and world health authorities are trying to prepare for a potential outbreak. Because the virus mutates continually, creating a vaccine in advance is problematic. For example, scientists have already found that a vaccine designed for the 1997 strain of bird flu does not work against a 2003 strain. "Current vaccines contain only a single version of a given flu subtype," Deem said. "We wanted to gauge the effectiveness of a vaccine that contained multiple versions of a given subtype." World health authorities currently test the efficacy of proposed flu vaccines using either ferrets, which can contract the same forms of flu as people, or genetic assays. Rice's new computerized method could be a cheaper and faster alternative. With the new method, flu virus mutations are assigned numerical scores. Deem, Rice's John W. Cox Professor of Bioengineering and professor of physics and astronomy, and colleagues developed the method so they could assign a number that captured the amount of difference or similarity between strains. The method can also be used to test how effective a vaccine will be against divergent strains. To verify this, the team checked their results against flu vaccine data collected by the World Health Organization from 1971 to 2004. "For seasonal influenza, we validated our model against observational data compiled by the World Health Organization's Global Influenza Surveillance Network," Deem said. "We also ran tests against bird flu data. We found that multiple-component bird flu vaccines appeared to be helpful in controlling the simultaneous multiple introduction of bird flu strains." Influenza viruses are like chameleons. They constantly change the patterns on their outer surface to avoid being targeted by antibodies. This rapid mutation rate is the reason seasonal flu vaccines must be changed annually. However, the vaccines sometimes offer less than ideal protection against newly evolved strains. It takes about six months to produce annual vaccine supplies; also, ideal vaccine strains are often difficult to produce by the standard hen's egg technology, and alternative strains are substituted. "Oftentimes, bird flu seems to emerge with multiple strains, and something similar can happen with newly released or evolved strains of seasonal flu as well," Deem said. The computational approach Deem will discuss is able to estimate the need for and the efficacy of a multiple-component vaccine in the face of the emergence of multiple flu strains. Each year, world health authorities create a flu vaccine that protects against three types of seasonal flu -- two subtypes of type A flu and one subtype of type B. Rice University |
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| Related Flu Vaccine Current Events and Flu Vaccine News Articles People with less education could be more susceptible to the flu People who did not earn a high school diploma could be more likely to get H1N1 and the vaccine might be less effective in them compared to those who earned a diploma, new research shows. Poll: Many parents, high-priority adults who tried to get H1N1 vaccine unable to get it A new national poll from Harvard School of Public Health (HSPH) researchers found that a majority of adults who tried to get the H1N1 vaccine for themselves or their children have been unable to do so. Initial Results Show Pregnant Women Mount Strong Immune Response To One Dose of 2009 H1N1 Flu Vaccine Healthy pregnant women mount a robust immune response following just one dose of 2009 H1N1 influenza vaccine, according to initial results from an ongoing clinical trial sponsored by the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health. Flu vaccine given to women during pregnancy keeps infants out of the hospital Infants born to women who received influenza vaccine during pregnancy were hospitalized at a lower rate than infants born to unvaccinated mothers. Pandemic flu vaccine campaigns may be undermined by coincidental medical events The effectiveness of pandemic flu vaccination campaigns - like that now underway for H1N1 - could be undermined by the public incorrectly associating coincidental and unrelated health events with the vaccines. Lessons from flu seasons past Pregnant women who catch the flu are at serious risk for flu-related complications, including death, and that risk far outweighs the risk of possible side effects from injectable vaccines containing killed virus, according to an extensive review of published research and data from previous flu seasons. Despite Risk, Older African Americans More Likely Than Others To Avoid Flu Vaccine A study about why African American seniors do or do not get influenza vaccinations finds that many of them do not have accurate and complete information about the flu itself, the safety and efficacy of the inoculations, and the ease and necessity of getting the shots. Earlier flu viruses provided some immunity to current H1N1 influenza, study shows University of California, Davis, researchers studying the 2009 H1N1 influenza virus, formerly referred to as "swine flu," have identified a group of immunologically important sites on the virus that are also present in seasonal flu viruses that have been circulating for years. Survey finds just 40 percent of adults 'absolutely certain' they will get H1N1 vaccine In a new survey, Harvard School of Public Health (HSPH) researchers found that just 40% of adults are "absolutely certain" they will get the H1N1 vaccine for themselves, and 51% of parents are "absolutely certain" that they will get the vaccine for their children. Surgical masks and N95 respirators provide similar protection against influenza A McMaster University study has found that surgical masks appear to be as good as N95 respirators in protecting health-care workers against influenza. More Flu Vaccine Current Events and Flu Vaccine News Articles |
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