Forms and Instructions
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Do you have the wrong idea about the flu and flu shots? Many people do. Some believe that the vaccine is worthless, or worse, that it can cause the flu. Many think nausea and vomiting are "the flu." Others call a bad cold the flu. Influenza is a viral illness that causes fever, muscle aches, headache, and cough. It may be complicated by pneumonia, either viral or a secondary bacterial pneumonia. It may be a minor illness or it may be fatal. The illness is caused by three distinct viruses, and within each virus, many different strains occur. The strains differ from year to year, because the virus is able to re-assort its RNA to produce different surface proteins. These proteins are what the body recognizes to set the immune response in motion, so having the flu last year won't protect you from this years strain.
A flu shot can not cause the flu. The flu virus is grown in chicken eggs, then harvested, inactivated and extensively purified. Early each spring, a group of influenza experts decide what strains of influenza to include in next winters vaccine. They base this decision on the strains that circulated late the previous winter. The vaccine is really three separate vaccines — two influenza A and one influenza B. The vaccine has been shown to be about 70-80% effective in reducing the occurrence of the disease and the associated mortality. Because it is grown in chicken eggs, it should not be used in persons allergic to eggs. Local side effects, such as soreness and redness around the injection for one to two days may occur in up to one-third of the recipients. Fever, muscle aches, and a general feeling of unwellness occur rarely, usually within 6 to 12 hours after the vaccination, and last one to two days. The most common cause of becoming ill after a flu vaccine is acquiring a cold or other virus that is circulating in the community at that time.
Who should get the flu vaccine? It is recommended for persons at increased risk for complications of influenza, including adults and children with chronic lung or heart disease, nursing home residents, persons age 65 or older, persons with diabetes, kidney disease, immune suppression, and children and teenagers who must take continuous aspirin therapy. It is also recommended for persons capable of transmitting influenza to high risk persons. This includes health care providers in hospitals, outpatient settings, homes and household members of high-risk persons.
Besides being accused of causing the flu, the flu vaccine has been accused of being ineffective. Younger people develop higher levels of protective antibodies than elderly people do, and older people clearly benefit from the flu vaccine. A 1994 study published by the New England Journal of Medicine showed that elderly vaccine recipients had a 48-57% reduction in hospitalization for pneumonia and influenza. There was a 27-39% reduction for all acute and chronic respiratory conditions. Vaccination was also associated with a 37% reduction in the rate of hospitalization for congestive heart failure. Most striking of all, vaccination was associated with reductions of 39-54% in mortality from all causes during the three influenza seasons studied.
We have two established anti-viral medications for the treatment of influenza — amantadine and rimantadine. They work only against influenza A. Both must be used early in the infection to be effective, and neither stops the infection in it's tracks. They can shorten the illness and reduce it's severity. They can also be used during the influenza season in a high-risk setting for the prevention of infection. This is not a substitute for vaccination, but primarily a control measure when influenza A outbreaks occur in high-risk settings. Some promising new anti-virals are on the horizon. Work is also being done on more effective vaccines. For example, vaccine administered as nose drops may be more immunogenic (provide better immunity) because it promotes more antibodies in the location where it is administered. For now, the influenza vaccine is the best protection available for the prevention of influenza and its many potential serious complications.
Dr. E. Patricia Gill is a physician at Longmont Clinic. She is board certified in internal medicine and infectious disease.
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