Prevention

Options for heading off an attack of influenza have increased steadily in recent years.

• Vaccination - People who are at a high risk of infection with influenza (such as health care workers), or are more likely to get complications if infected, should get vaccinated against the disease every year. Each year's flu vaccine is different because it is adjusted to combat whatever virus strains are expected to be circulating that season. The vaccine is particularly recommended for people who:

  • Children, aged 6-23 months

  • Children or teenagers who are receiving long-term aspirin therapy

  • Pregnant women who will be in the second or third trimester during the epidemic

  • Adults, 50 or older, even if in good health

  • Adults or children who have certain chronic illnesses, especially those of the heart, lung or kidneys; diabetes; or severe forms of anemia

  • Adults or children who have illnesses or are taking medications that reduce or suppress immune defenses

  • Live in nursing homes or assisted-living centers

  • Health care professionals and others who are in close contact with anyone in the above high-risk groups

  There is growing support for a policy of recommending the influenza vaccine to all adults, and many doctors will give the vaccine to any adult who requests it.

  The standard influenza vaccine is 70% to 90% effective in helping healthy people under age 65 to avoid the disease or lessen its severity. For maximum effectiveness, doctors advise people to get vaccinated in October or November, the start of the flu season. Healthy people between the ages of 5 and 49 have an alternative to the flu shot. FluMist is an intranasal vaccine spray that appears to offer similar protection. It uses a deactivated live virus rather than the killed virus in the shot. FluMist is not any more effective than the standard flu shot. Because FluMist is so new, people at the highest risk for influenza (people over age 49 and those with chronic health conditions) should receive the injected vaccine.

• Good hygiene - The virus usually is passed through the air, by coughing. It also is passed by direct contact, such as shaking hands or kissing. For this reason, practicing good hygiene - covering your mouth when you cough and washing your hands frequently - can help you to avoid getting the flu or spreading it to others.

• Antiviral drugs - Two older antiviral drugs - amantadine (Symmetrel) and rimantadine (Flumadine) - and two newer ones - zanamivir (Relenza) and oseltamivir (Tamiflu) - can reduce your chance of getting the flu by 70% to 90%, if they are taken just before an expected outbreak. Zanamivir is a spray that is inhaled through the mouth. The others are pills. The older drugs, particularly amantadine, tend to have more side effects than the newer drugs. The side effects include nausea, vomiting, irritability, depression and difficulty sleeping. Zanamivir generally should be avoided in people who have asthma or chronic lung disease, since it may worsen wheezing. The two older drugs are effective only against the influenza type A virus, whereas the newer drugs also treat type B. The newer drugs are much more expensive.