Abstract: A bio-functional air filter medium is provided with a at least one particle filtration layer that retains particles and at least one bio-functional carrier coated with or having embedded therein antimicrobial, anti-viral and anti-allergenic materials. An air filter element having the bio-functional air filter medium is also disclosed. The bio-functional air filter medium is adapted to bind and capture allergens and block metabolism of bacteria, and provide anti-viral activity to effectively inhibit/deactivate viruses, all while filtering air in high flow, low pressure drop residential, HVAC or air purifier applications.