Influenza! (US data) 1) Plummeting mortality over the 20th century. 2) Pandemic influenzas after 1918-20…

Influenza! (US data) 1) Plummeting mortality over the 20th century. 2) Pandemic influenzas after 1918-20 often less lethal than non-pandemic influenzas. 3) Vaccination not responsible (wide use only since 1980). Ecological causes suggested. From: https://t.co/aszvgjcOIu https://t.co/h18NfOONBs