If you were born in the last 70 years, you probably take your ability to avoid dying from diphtheria for granted—if you’ve even heard of it. The bacterial infection creates a poison that can cause a thick membrane to develop in the nose, throat and airway, making it difficult to breathe and swallow. In 1921, before there was a vaccine, it killed more than 15,000 Americans, according to the Centers for Disease Control and Prevention. From 2004 to 2014, only two cases of diphtheria were reported to the CDC, thanks to widespread vaccination, which became routine in 1940.
“I think vaccines are one of the greatest achievements of modern medicine,” says Sean Murphy, M.D., Ph.D., assistant director of the Clinical Microbiology Laboratory at University of Washington Medical Center and assistant professor in the Department of Laboratory Medicine at UW. He is currently working on developing a vaccine for malaria.
Without vaccines, the World Health Organization estimates that there would have been 5 million more deaths each year between 2010 and 2015. But how do they work? And are they really still important in the U.S. today? Here’s what you should know.
How Vaccination Works
Do you ever think about all of the germs you come into contact with every day? From washing your dishes with a sponge to riding on public transportation or petting your dog, most things you interact with are teeming with bacteria. One recent study found more than 17,000 bacterial gene copies on the cell phones of high school students. But most people don’t have to worry about getting sick from scrolling Instagram.
That’s thanks to your immune system. The organs, cells and tissues that comprise the immune system work like little guards, attacking the invaders—hopefully before they make you sick. When you’re immune to something, your body knows to fight it off. But when you aren’t, it can get through the gates and make you sick.
“The goal of a vaccine is to sort of mimic that infection, or educate the immune system, so that if it sees the pathogen another time—this time when it’s a live pathogen—it will know to search and destroy that,” says Murphy.