The flu is highly infectious and is a serious viral respiratory infection. Whereas with other viral respiratory infections the symptoms usually are mild and most people can continue working or going to school while ill, with the flu, the symptoms are severe and prolonged and cause individuals to miss days of work or school. The infection stresses the body. In addition, superinfections may occur. It is important to prevent the flu by vaccination. Although there are medications to treat the flu, they are expensive, not as effective as vaccination, and need to be started within 24-48 hours of the start of symptoms.
Flu vaccines are routinely available for seasonal influenza, but these vaccines are not likely to be protective against flu caused by the novel H1N1 (formerly termed swine flu) virus. A vaccine against the novel H1N1 flu is in production as of summer 2009 and may be ready for administration in fall of 2009.
There are two types of seasonal flu vaccines, the injection (with killed virus) and nasal spray vaccines (containing live but weakened virus).
Flu season can begin in October and last as late as May. October and November are considered the best times to receive the vaccination, but it is still effective when administered later.
Side effects include soreness at the site of the injection, muscle aching, fever, and feeling unwell. Very rarely, serious allergic reactions have been reported.
