Immunization of subjects aged 65 and older has led a 31 to 70% decrease in
the number of hospitalizations and a 31 to 68% decrease in mortality.
The more serious the direct or induced effects of influenza (complications of
infection in high-risk individuals or even death) the greater the protection
conferred.
This is particularly true given the fact that the influenza virus renders the
subject more vulnerable to other infections, including pneumococcus,
staphylococcus or H. influenzae, explains why the vaccine is able to
confer protection against child pneumonia or acute otitis.
The vaccine's ability to significantly curb the number of serious
consequences and thus reduce medical costs of the illness is well documented.
Studies have shown that the savings in direct costs alone (ambulance,
hospitalization - whether complications proved fatal or not) are greater than
the costs of vaccinating all individuals over 65 and other high-risk patients (27,
p.155).
