Today’s Wonder of the Day was inspired by Peyton . Peyton Wonders, “How do they make vaccines” Thanks for WONDERing with us, Peyton !
Uh oh. It's that time again. You just overheard a snippet of a phone call that sounded suspiciously like making an appointment for you to see the doctor.
Since you're not sick, that can only mean one thing: it's time for your annual check-up. While that's not a huge deal, you remember that you usually don't escape your annual check-up without getting a few shots.
While no one likes getting shots, you understand that it's necessary. The vaccines that you're given help ensure that you don't get a wide variety of terrible diseases. Still, that needle isn't anything to look forward to.
Have you ever given much thought to how vaccines are made? Over time, scientists have developed several methods for creating effective vaccines. Let's take a closer look at some of the most popular methods.
The MMR (measles, mumps, and rubella), chickenpox, and shingles vaccines are all made using weakened viruses. By weakening the viruses that cause these diseases, scientists ensure that they reproduce poorly when injected into the body in the form of a vaccine.
A full-strength virus can reproduce thousands of times over the course of an infection. A weakened virus, however, usually reproduces fewer than 20 times. The result is that weakened viruses don't produce disease, but they reproduce enough for the body to build up a resistance and even produce memory cells that will continue to fight the virus in the future.
Weakened-virus vaccines usually produce lifelong immunity with only one or two doses. The downside to these types of vaccines is that they usually can't be given to people with weakened immune systems.
Influenza, rabies, hepatitis A, and polio vaccines are made using completely inactivated viruses. Since the virus has been killed chemically, it can't cause disease, but it can still be recognized by the body in order to produce immunity.
Inactivated-virus vaccines can be given to people with weakened immune systems. However, these types of vaccines usually require several doses to achieve immunity.
Many other types of vaccines are made by using only one part of a virus or bacterium. For example, a particular protein or toxin associated with a virus or bacterium can be inactivated and used to create a vaccine that can be given to people with weakened immunity in order to achieve lifelong immunity with as few as three doses.
As diseases evolve, scientists continue to look for ways to create vaccines to protect people from harm. Some people also experience decreased immunity over time. When this occurs, vaccines called "boosters" can be given to restore full immunity. This happens frequently with vaccines for tetanus, for example.