In the year 1900, influenza and pneumonia caused around 202 deaths per 100,000 population in the United States. By 2018, the rate of death from influenza and pneumonia had decreased to around 15 deaths per 100,000 population. Nevertheless, influenza and pneumonia remain among the ten leading causes of death in the United States, accounting for 2.1 percent of all deaths in 2018. It was estimated that during the 2018-2019 flu season there were over 35.5 million cases of influenza and 490,600 hospitalizations due to influenza.
Although receiving an annual seasonal influenza vaccination is the best way to protect against influenza, many people in the United States do not get regularly vaccinated. During the 2018-2019 flu season only 35 percent of those aged 18 to 49 years received a flu vaccination, while 68 percent of those aged 65 years and older had been vaccinated. The effectiveness of the influenza vaccine varies from season to season and depends on the age and health status of the receiver. Nevertheless, during the 2018-2019 season, it was estimated that for every 4,127 people who received an influenza A (H1N1) vaccination, one hospitalization was prevented. During that time, it was estimated that influenza vaccinations prevented over 1.3 million influenza cases among children aged 6 months to 4 years, alone.
