What’s the Difference Between Inoculation, Vaccination, and Immunization?

(Last Updated On: March 8, 2021)

Alright so inoculation, vaccination, and immunization are a lot of words that have a lot of syllables in them. They sound like they mean both the same and different things, which is largely true. The terms are often used interchangeably and for lay people they functionally might as well be synonyms. But we love getting into the nitty gritty of words so let’s talk about the difference between inoculation, vaccination, and immunization. Also get vaccinated if you’re able. No seriously. 

Inoculation Etymology

So let’s tackle things broadly and then move our way down. Inoculation is the process of inducing immunity to infectious disease. So there you go, getting vaccinated is a means of getting inoculated. 

In case you were wondering where the word comes from, inoculation is derived from the Latin for “in-oculus,” literally “in the eye.” Which doesn’t sound like it makes a lot of sense, unless you’re getting vaccinated in your eyeball. That’s going to be a no from us, chief. Stick it in our arm and call it a day. So why is the word “inoculation” related to eyes? Well it’s not, at least not the eyes inside of your head. It refers to plant buds–also known as eyes. The term “inoculation” predates more modern medicinal practices; originally it was applied to plants. Inoculation was grafting the buds (eyes) of one plant to another.

Early Inoculation

Before vaccines there was variolation, commonly with smallpox. The idea was to give someone a mild smallpox infection that wouldn’t give them a certified bad time, but would make them immune to smallpox. Britain and Massachusetts back in the colonial days had variolations dating back to 1721–of which they sourced from the Ottoman Empire. The Ottomans probably figured out variolation when it reached Constantinople by the 1650s. Where did the Ottomans pick it up from? Many cite India and China. 

China’s earliest written records for variolation date back to 1549, though literature from the time also complains about inoculators being tight lipped about their methods. Poorly documented practices from Taoist or Buddhist monks in the 1000’s suggest some kind of variolation processes as well. India also independently figured out variolation–at least their relative elites did. 

So Vaccination and Immunization

Immunization is pretty easy to pick apart–it’s making someone immune to something. Because contemporary immunization processes are built on vaccination, you’ll typically see vaccination as the process of immunization. So you can kind of turn it into a chain. Inoculation is the process of granting immunization, which is done via vaccination. At that point it’s basically the same thing. Vaccination is getting a vaccine, and immunization is becoming immune. A rose is a rose, what a concept. 

Inoculation and Immunization

You might then think inoculation is immunization. But to be super pedantic, inoculation is the process of artificially inducing immunity. You can become immune to diseases naturally over time. It’s called getting sick and then getting better. The exact same stuff almost never makes you sick again–your immune system is made up of memory B and memory T cells. When you’re sick, your body has to almost manufacture a specific cell to counter the pathogen. Once you get better, most of those cells aren’t needed anymore, so you stop making them. But you keep the memory cells around–and once the same disease comes back they activate to bring forth the same cells that got you better in the first place. 

Bam. You’re immune. Which means you might be asking why you have to get a flu vaccine at regular cycles or why you can get the common cold more than once. That’s because viruses play the same game. They mutate and change over time, and they change enough to where our memory cells don’t line up anymore. It’s an arms race where the same weapon never works twice, and both your body and the flu keep having to change things up–and they’re always playing catch up with one another. 


So why did we go through a super simplified explanation of immunity? Because that process is, very broadly, what vaccines use. They set up memory cells so when you really get hit by, say the flu, you’ve already got the immune response good to go. No need to waste valuable time creating an immune response–time a disease would be wreaking havoc on your insides. 

That whole shebang is vaccination. 

Also vaccinate if you are able to.  

See if you know whether or not a vaccine exists for something here.



About Kyler 727 Articles
Kyler is a content writer at Sporcle living in Seattle, and is currently studying at the University of Washington School of Law. He's been writing for Sporcle since 2019; sometimes the blog is an excellent platform to answer random personal questions he has about the world. Most of his free time is spent drinking black coffee like water.