The mortality rate from influenza in the United States is by far highest among those aged 65 years and older. During the 2023-2024 flu season, the mortality rate from influenza for this age group was around 32.1 per 100,000 population. The burden of influenza The impact of influenza in the U.S. varies from season to season, but in the 2023-2024 flu season, there were an estimated 40 million cases. These cases resulted in around 470,000 hospitalizations. Although most people recover from influenza without requiring medical treatment, the disease can be deadly for young children, the elderly, and those with weakened immune systems or chronic illnesses. During the 2023-2024 flu season, around 28,000 people in the U.S. lost their lives due to influenza. Impact of vaccinations The most effective way to prevent influenza is to receive an annual vaccination at the beginning of flu season. Flu vaccines are safe and can greatly reduce the burden of the disease. During the 2022-2023 flu season, vaccinations prevented around 2,479 deaths among those aged 65 years and older. Although flu vaccines are usually cheap and easily accessible, every year a large share of the population in the U.S. still does not get vaccinated. For example, during the 2022-2023 flu season, only about 35 percent of those aged 18 to 49 years received a flu vaccination.

Chicken macrophages were treated with TLR ligands prior to, simultaneously, and post- infection with AIV. Supernatants were collected 14 hours post infection to measure virus titre via HA. There were four replicated for each treatment group. Titre of virus represented as Log geometric mean of haemagglutination unit (HAU) of four replicates.aHours relative to virus infection.*Significant difference (P < 0.05) between treatment group and medium control group.CRepresents control group which was not stimulated with TLR ligands.AIV titres in supernatants of MQ-NCSU cells following treatment with TLR ligands.