THE CLINICAL EFFICACY OF INFLUENZA VACCINATION

Inactivated influenza vaccine was developed approximately 50 years ago . The formulation has been continually improved, and its efficacy in p reventing morbidity in healthy adults repeatedly demonstrated. Whether or not the vaccine is able to prevent hospitalisation and other compl ications of influenza in older individuals has been resolved by recent observational studies. During periods of influenza virus circulation, the vaccine has also been shown to be effective in preventing hospita lisation and, in some cases, death from all causes and specific causes such as all respiratory conditions. Antivirals are also available for use against type A influenza, and may be especially valuable when ant igenic change in the virus occurs. Now that questions regarding clinic al effectiveness have been answered, vaccine and antivirals should cer tainly be more extensively used than in the past. The determinations o f positive clinical effectiveness, which are based on observations of actual use of the vaccine, can form a basis for calculation of cost ef fectiveness.