| Popis: |
Influenza/pneumonia is the only infections disease(s) among the top ten causes of death in the U.S. (Check, 1984). Influenza virus kills an average of over 20,000 people each year in the United States (Katz, 1985). In addition, the illness has a substantial economic impact. Schoenbaum (1987) estimated that the total direct cost of influenza (health care cost) exceeds $1 billion per year in the U.S., with the actual cost (including lost productivity) on the order of $3 to $5 billion per year. Yet, until recently at least, only about 20% of the over 43 million Americans at risk of death from influenza by virtue of their age or underlying medical condition receive vaccinations (Mostow, 1986; Check, 1984). If there is a close match between the vaccine strain and the circulating strain, protection can be 70 to 80% in the adult population (Douglas, 1990). Protection may be lower in the infirm elderly who are at greatest risk (Gross et al, 1989). |
