Читать книгу Vaccines For Dummies - Sharon Perkins - Страница 21

When you say, “I caught the flu,” you’re often referring to an influenza virus. These are the viruses that cause the sniffles, coughs, achy muscles, fever, and sore throat that can make your life miserable for a week or so. But some influenza viruses — often simply called the flu — can also make you extremely — even deathly — ill. Up to 500 million people are infected by influenza viruses worldwide. In the United States, between 12,000 and 61,000 have died from influenza viruses each year from 2010 through 2020.

Influenza viruses fall into one of four different types — unimaginatively named A, B, C, and D. Influenza viruses can affect many animal species. Some flu viruses just remain in other animals, but some flu subtypes can spread to us from animals, especially farm animals like chickens and pigs. Science has created influenza vaccines against some but not all types. The yearly flu vaccine consists of antigens against type A and type B influenza viruses.