Finally, Sars2 causes immunity damage. It kills needed T-cells and damages the immune systems capability to respond to new infections. Sars2 uses ACE2 receptors found in most cells in your body to enter cells and can spread throughout your body to brain, heart, and in your circulatory system to other organs. Influenza cannot and does not do this, as it only binds to cells within the respiratory tract & lungs.
Influenza immunity also lasts > 3yrs. Sars2 immunity is gone in < 1yr.