Flu Vaccine (12.25.03) - Vaccines could be made more quickly and better target the actual strain of flu that's out there. Flu Vaccine Shortage (07.20.00) - Public health officials are preparing for a shortage of available flu vaccine. Is it a Cold or Flu? Influenza Vaccination Recommendations This year's sudden flu shot shortage may have some health consequences beyond just this year. As this ScienCentral News video reports, researchers have found that alternately getting and skipping flu shots may actually increase your chance of getting sick. Original Antigenic Sin On October 5, the Centers for Disease Control (CDC) was notified by the Chiron Corporation that none of its influenza vaccine would be available for distribution in the United States for the 2004– 05 influenza season. This will reduce the expected supply of flu shot available in the U.S. for the 2004– 05 flu season by approximately one half . Because of this, the CDC is giving the following groups priority for vaccination: all children aged six– 23 months; adults aged 65 years and older; people age two– 64 years with underlying chronic medical conditions; all women who will be pregnant during the influenza season; residents of nursing homes and long-term care facilities; children aged six months– 18 years on chronic aspirin therapy; health-care workers involved in direct patient care; and out-of-home caregivers and household contacts of children aged less than 6 months. But one bioengineer says that, even if you're not in one of those groups, if you got a flu shot last year, and don't get it this year, you’re at greater risk, too. In fact, you may be worse off than if you'd never gotten a flu shot at all. A flu shot gives the immune system something to "remember" to fight off. But the flu virus mutates very rapidly, and the vaccine is changed every year, so skipping that shot one year can mislead the immune system into thinking it knows how to combat the latest strain. "The immune system may use its memory from last year and try to combat this year's flu with last year's antibodies," says Deem. "The memory in the immune system is actually leading the immune system astray." As a result, Deem says, you may be more likely to get the flu during that year, compared to your chances of illness if you had never gotten a flu shot in previous years. Deem says an annual flu shot keeps the immune system up to speed. "This allows the immune system to build up its repertoire of antibodies that can control the flu for that particular individual," he says. "For rapidly mutating strains such as the flu, the vaccine needs to contain the most likely strains. And it's not simply that all the strains can be included in the vaccine, because the strains interfere with each other to some extent, so there is a limit to how many strains can be put into the vaccine every year." Deem's research appeared in the August 8, 2003 issue of the journal Physical Review Letters and was presented on September 8, 2003 at the national meeting of the American Chemical Society . It was funded by the National Science Foundation (NSF), and the Camille and Henry Dreyfus Foundation, Inc.

ann marie cunningham and orrin schonfeld, michael deem, rice university.,