system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does anti-venom work, and why does it require more venom to be produced (or is this a misconception)?

Sneks, how do they work?
gpt
Anti-venom is made by injecting small amounts of the venom collected from the venomous animal into another animal. The animal's body creates antibodies(things in the blood which attack foreign things in your body that shouldn't be there) to fight off the venom. Then those venom fighting antibodies are extracted from the animals blood and presto. You can now give them to a person who has been bitten and give their body a huge amount of antibodies to help neutralize the venom in their blood before it does more damage. There are some antivenoms that can be used to treat multiple different venoms and also ones that are specific to one kind.

If you ever saw the princess bride you might remember that a character fed himself tiny amounts of a deadly poison to build up an immunity to it. We are doing the same thing but instead of making ourselves resistant to the venom (there are people who have done this though it's stupidity dangerous) we make another animal resistant and then use their blood to extract the antibodies and give them to people who have been bitten.