Feb 19th – The flu, a.k.a. influenza, is a respiratory infection caused by strains of orthomyxoviridae. The word “influenza” comes from the Italian word for influence – back when the stars were thought to influence the start of an epidemic! Every year 5% – 40% of the population gets the flu. Fortunately, most people recover completely in a couple of weeks. Even more fortunately, since there are only about a dozen different flu viruses, vaccines have been developed that can be up to 90% effective in preventing infection in the first place. These vaccines, or “flu shots,” are best taken in the fall before the flu season starts, since it can take several weeks for them to become fully effective. (However, since eggs are used to make the vaccines, people who are allergic to eggs should not get the shots.) In 1918, before there were any vaccines, there was a worldwide pandemic of Spanish flu. Twenty million people were killed. Maybe today we should thank our lucky stars for the vaccines! #365DaysOfMicroscopy