• Question: What is the first step in developing an anti-venom?

    Asked by Joshua Moore to Adam on 12 Jun 2017. This question was also asked by BrynSleeps, Macy & Liv.
    • Photo: Adam Hargreaves

      Adam Hargreaves answered on 12 Jun 2017:

      Hi 622actj34, that’s a great question!

      The first problem we have for making antivenoms (especially for snakes) is that the types and amounts of different toxins (the proteins that cause all the damaging effects) in a particular venom can vary a lot. Even in the same species of snake there can be huge differences depending on geographical location. For example, Mojave rattlesnakes in Arizona in the USA can have either neurotoxic (affecting the nervous system), haemotoxic (affecting the blood system), or a hybrid (mixture of the two types) venom. This is all down to them either having or lacking a particular toxin, funnily enough called Mojavetoxin, which varies depending on where in Arizona you find the snakes. The same is also true for bigger distances, an antivenom made against the snakes found in Australia will probably not be very effective against treating bites by snakes found in Asia. Because of this it’s important to first choose the area you want to make the antivenom for, and also if you only want to make it to work against one type of snake, or a number of different snakes found in a particular area.
      Once you’ve decided that, it’s time to go out and find some snakes!
      To make antivenom the traditional way, you first need samples of venom which are collected by “milking” the snakes. You might have seen this on TV, this is when a snakes venom glands are emptied manually (keeping fingers nicely out of the way of the pointy end…) to collect the venom.
      The next step is to inject very small amounts of venom into a big animal, usually it’s horses which are used. Whilst this amount of venom would probably kill us humans, the horses aren’t harmed by this process. What happens next is the horse’s immune system starts making antibodies against the toxins in the venom, exactly like our immune system when we’re trying to fight off an infection. Then we can purify those antibodies, and that’s it, we have an antivenom!
      That’s a bit of an essay I know, I hope I’ve answered your question, do let me know in a comment if not!

Comments