Every spring, some of the greatest minds in medicine match wits with one of the craftiest viruses on earth – influenza. By examining statistics and patterns of disease from the previous year, scientists at the Centers for Disease Control and Prevention (CDC), and the World Health Organization (WHO) and experts around the world try to predict which strains of influenza will be prominent when flu season officially begins the following December.
Based on those patterns, a vaccine is created months before flu season to protect against what are expected to be the common strains of flu for that year. If those calculations are correct, the flu vaccine will be 70 to 90 percent protective against illness, and 80 percent effective against death in the most vulnerable population — people age 65 and older. But if the virus mutates faster than expected, the vaccine is less effective.
Although a flu vaccine is no guarantee against illness, it offers the best protection available. Since most flu deaths are among the elderly and those with chronic diseases, the vaccine is especially important for anyone age 65 or older, and anyone with a weakened immune system, chronic heart disease, chronic pulmonary disease, diabetes or asthma. Also, anyone who works in a key position who may be needed in case of emergency (such as police, firefighters and military personnel) should be immunized.
Anyone who wants to avoid the misery of flu should get vaccinated between late October and mid-November.
Wait much longer and your body won't have enough time to build up antibodies before flu season starts in December; get vaccinated earlier and the protective effects of the vaccine may wear off before the flu season ends in March. Since the virus changes every year, new vaccines are needed every year.
The 1999-2000 Flu Vaccine Recommendations
The Advisory Committee on Immunization Practices (ACIP) strongly recommends vaccination for people who are at a higher risk of complications from a bout with the flu.
These groups include:
- People 65 years or older
- Residents of nursing homes and long-term care facilities
- Adults and children who have asthma, or chronic lung or cardiovascular disorders
- Adults and children with chronic metabolic diseases, including diabetes mellitus, kidney and blood disorders, or immunosuppression, including those caused by
- Children, up to 18 years old, who are receiving long-term aspirin therapy, which may increase their risk of developing Reye syndrome
- Women who will be in the second or third trimester of pregnancy during the flu season.
In mid-September 1999, the American Academy of Family Physicians (AAFP) announced it was lowering its recommended age for flu vaccination from 65 years old to 50. In doing so, the AAFP is going beyond the guidelines laid down by the Advisory Committee on Immunization Practices (ACIP), the most widely accepted national authority on immunization