Influenza is a major cause of illness and suffering in all age groups. Influenza vaccination is the cornerstone and primary method for preventing influenza and its severe complications that often result in hospitalization or death especially in high-risk persons. The primary target groups recommended for annual vaccination are;
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persons at increased risk for influenza-related complications: everyone of 65 years or older, children aged 0 – 23 months (influenza vaccination is possible in children of 6 months or older), pregnant women, and persons of any age with certain chronic medical conditions;
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persons aged 50 – 64 years because this group has an elevated prevalence of certain chronic medical conditions; and
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persons who live with or care for persons at high risk: health-care workers and household contacts who have frequent contact with persons at high risk and who can transmit influenza to those persons at high risk.
Currently licensed inactivated influenza virus vaccines have an excellent safety profile and are highly effective in preventing acute illness and serious complications. In addition to providing substantial health benefits, vaccination is also associated with significant economic benefits, not only among the elderly but also among healthy working adults and even children. Hundreds of millions of doses of these vaccines are used worldwide each year.
Although antiviral drugs can be used as a prophylaxis against influenza, vaccination is the first line of defense in the prevention of influenza. However, if vaccination is not performed during an epidemic, or if vaccinated subjects remain unprotected during an influenza outbreak, for instance because of a mismatch between a circulating influenza strain and the strains in the vaccine, the use of antiviral drugs can be considered. Also for patients with a known hypersensitivity to influenza vaccine the use of antiviral drug is indicated. If the new generation of antiviral drugs are administered within 24 to 48 hours after the onset of symptoms they can reduce the duration of uncomplicated influenza A and B illness by approximately 1 day.
