Influenza virus infections occur every year in the United States but vary greatly in incidence and geographic distribution. Efforts to prevent or control influenza in the U.S. have been aimed at protecting persons at risk of serious illness or death.

The influenza virus vaccine for the 1998-1999 season contains 15 micrograms each of HA (hemagglutinin antigens) of A/Beijing/262/95-like (H1N1), A/Sydney/5/97-like (H3N2), and B/Harbin/07/94 (B/Beijing/184/93-like) in each 0.5 mL dose. Gelatin 0.05% is added as a stabilizer and thimerosal (mercury derivative) is added as a preservative.

WHO SHOULD BE IMMUNIZED?

The influenza vaccine is strongly recommended for:
1. Any person greater than or equal to six months of age, who by virtue of age or underlying     
        conditions is at increased risk for complications of influenza.

2. Health care workers and others (including household members) who may have close contact
        with high risk persons.

3. Any other person who wishes to reduce his/her chance of becoming   infected with influenza, 
        even if that person is not at increased risk forcomplications.

For persons infected with HIV, vaccination is advised because influenza may result in serious illness and complications in these individuals. The effectiveness of vaccination may be reduced due to the inability of HIV patients to mount an antibody response.

Persons with acute febrile illnesses usually should NOT be vaccinated until symptoms have abated. Inactivated influenza vaccine should NOT be given to persons with known hypersensitivity to eggs.

The vaccine is considered safe for use during pregnancy. Pregnant women who have medical conditions that increase their risk of complications from influenza should be vaccinated. To minimize the theoretical possibility of teratogenecity, it is reasonable to administer the vaccine after the first trimester if immunization will be accomplished when the influenza season begins.

High levels of influenza activity generally do not occur before December in the United States. Influenza vaccine may be offered to high risk patients presenting for routine care or hospitalization starting in September. Organized vaccination campaigns for high risk persons are optimal from October to mid November.

In facilities such as nursing homes, it is important to avoid administering the vaccine too far in advance of the influenza season, because antibody levels start to decline in a few months. If regional influenza is expected to begin earlier than December, vaccinations may be given as soon as the vaccine is available.

The recommended site of vaccination is the deltoid muscle for adults and older children. The anterolateral aspect of the thigh is recommended for infants and small children. NEVER administer the vaccine intravenously.

Because influenza vaccine contains only non-infectious viruses, it cannot cause influenza. The most frequent side effect is soreness around the injection site. Any significant adverse reactions should be reported to the Drug Information Center at ext 2328 and the appropriate VAERS (Vaccine Adverse Event Reporting System) forms will be completed. The following reactions have also occurred:

1. Fever, malaise and myalgia infrequently affect persons who have had no exposure to the
        influenza virus antigens. Symptoms usually occur six to 12 hours after the vaccination and
        can persist for one to two days.

2. Immediate, presumably allergic reactions are extremely rare post influenza vaccine
        administration. Persons who have anaphylactic hypersensitivity to eggs should not be    
        vaccinated. This includes people who develop hives,swelling of the lips, or respiratory
        distress after eating eggs.