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Brandon432 t1_ivlw1dv wrote

Let's use snake venom as an example. Venom is extracted from a venomous snake and then dosed (carefully) into a mammal, often a horse or sheep. That animal develops antibodies to fight the venom. Those antibodies are harvested (from blood serum), processed, stabilized, and packaged into antivenom for humans or pets. The antibodies can be included in whole (generally more effective but high risk of allergic reaction) or just certain parts (less effective, lower allergic risk).


Jackhow123 t1_ivnxbre wrote

will this trigger an immune respond in the patient?

The antidote antibodies are not yours. Will your body attack the antidote?


glacierre2 t1_ivo51lz wrote

If it is the first time, the body will take some time to make specific anti-antibodies, the antivenom has plenty of time to bind to the poison.

On a future second time (specially if the first was recent) you could get a race between the kinetics of your anti-antibodies binding the antivenom and the antibodies binding the poison. I would expect it would still work, but with decreased effect.

Finally, and this is the way that it always works, the poison + antibodies (yours or external) end up making a bigger clump that is consumed by cells of the immune system (macrophages), so ultimately you always get an immune response (but that does not necessarily mean an allergic reaction)


ukezi t1_ivo5jl1 wrote

I would assume that on second exposure there would always be a significant amount of your own antibodies to fight the venom.


Brandon432 t1_ivoqxqp wrote

Some patients develop a sensitivity to anti-venom. However, there is a common myth that you cannot have anti-venom more than once. It is totally false. If you do develop a sensitivity and have a reaction from a subsequent administration of anti-venom, that reaction is very easily managed in a hospital setting.

Addressing your comment below, anti-venom does not provide much if any lasting benefit. Snakebite vaccinations have not shown effective in humans or pets. First, the venom antibodies are relatively short-lived. Second, vaccinations work well when your immune system gets to have a fair foot race with an incubating infection. Snake bites don’t work that way. You can be delivered a lethal dose in half a second. No amount of vaccination can prep your body to catch up with a sudden envenomation.


Envenger t1_ivo30zr wrote

I am more interested to know how we found out that large mammals can develop antibodies for venom.


newappeal t1_ivop1tf wrote

It uses the same adaptive immunity that mammals (us included) use to develop antibodies for diseases. A key bit of information that seems to be missing from all the answers here is that most venoms are proteins, which is what mammalian immune systems usually produce antibodies against. (Not that we can only develop antibodies against proteins in particular - the key metric is the size of the molecule. Larger molecules have - by virtue of being large and structurally diverse - more unique structures than smaller ones, so chemical interactions between large molecules can be more specific and therefore stronger than those between small molecules.)

So armed with the knowledge that all or most mammals have similar immune systems that can develop antibodies against virtually any protein, and that venoms are proteins, it stands to reason that you can make antibodies to venom in most mammals. We use mammals like goats, rabbits, sheep, and horses to make other antibodies for scientific research, too.

Edit: A bit of a primer on poisons might be helpful here. As said above, we can develop antibodies against large poisonous biomolecules, whether they are enzymes that directly interfere with our biochemistry (making us sick), or they are receptors on viral particles that act during one step of a longer process that in the end interferes with our biochemistry (and thus make us sick). But some poisonous molecules are small, so we cannot develop antibodies against them. Arsenic (as arsenate), cyanide, heavy metals (lead, cadmium, radioactive iodine), and mustard gas are examples of such poisons. They act by either displacing small biomolecules (arsenate replaces phosphate; heavy metals replace other metal cofactors like iron, copper, and cobalt), competing for an enzyme's binding site (cyanide outcompetes oxygen), or reacting irreversibly with a biomolecule (mustard gas reacts with DNA). Because they are small, these poisons look a lot like other chemical species that occur frequently in biology (which is precisely why things like arsenic and lead are toxic), so antibodies against them would cause autoimmunity. Venom enzymes, being large, have unique structures that occur nowhere else in the target organism's own biology, and so they can be uniquely identified and bound by antibodies.


Nuvenor t1_ivo62rv wrote

trial and error. Guess how we figured out chocolate kills dogs. Or which mushrooms are edible.


Brandon432 t1_ivosgiy wrote

Debunking a common myth, it takes an awful lot of chocolate to kill a dog. My retrievers on several occasions crushed multiple king size Hershey bars, with no ill effect, other than a really messy yard for a couple days. Their bodies are as good as ours at expelling disagreeable materials.


googlecansuckithard t1_ivrxrih wrote

Not necessarily: it depends upon the breed. A relatively small chunk of dark chocolate (a square of a hersheys bar) will cause siezures in small breeds, and I can unfortunately testify to first hand experience to this. Chiuauas are particularly vulnerable.


RandomPhail t1_ivo56zs wrote

Aight, bet, SO…

Why can’t we take the antibodies from surviving cancer patients and distribute them to people with cancer


ukezi t1_ivo5qvq wrote

There isn't one cancer, each of them is their own thing, made up of your own cells that mutated. So antibodies from somebody else will not work.

There are some viruses that can cause cancers and we are developing vaccines against them.


Brandon432 t1_ivosqo4 wrote

First, cancer is a a single disease. It is 100 diseases. Even breast cancer, lung cancer, or skin cancer each comprise a half dozen common types and dozens more rare types.

Second, cancer isn’t a foreign cell, like a venom protein, bacteria, or virus. Cancer is your body’s own on cells run amok, replicating without control in places they shouldn’t.


googlecansuckithard t1_ivrxgad wrote

Correct me if im wrong, but antibodies are an immune response to biologicals such as viruses, bacteria, prions, etc. - not a reaction to purely chemical substances built from amino acids like vennom.


Brandon432 t1_ivt4so8 wrote

That’s incorrect. Body develops antibodies (also known as immunoglobulin) to most foreign substances (known as antigens). Virus, bacteria, fungi, allergens, toxins, venom, etc..


Rather_Dashing t1_ivupy8z wrote

Venoms are mostly proteins, so yes of course they can be a target of antibodies. Antibodies recognise fairly short fragments of proteins, not an entire virus or bacteria.

Also venoms are biological, and I don't think purely chemical means anything, everything is chemical


Otterly_Magic t1_ivxp3dx wrote

To add just a little bit to this: a “chemical” built purely “from amino acids” has a very good chance of being a protein or a peptide (aka miniprotein). Especially if it is coming from a biological source, such as a snake’s venom.


googlecansuckithard t1_iw1ombl wrote

Where the implucation would seem to be that proteins and peptides tend to be fragments of DNA/RNA in the biological context.


Tehnizzim t1_ivlztpn wrote

So we just poison horses lol. If they don’t die then why not just dose humans? I mean beyond the obvious that humans would rather test on animals. Is something about horses special for developing antibodies?


ThisTooWillEnd t1_ivm75ga wrote

Horses are heavy. Injecting very tiny doses of a venom makes them mildly ill for a few days, if at all. Then they can donate a gallon of blood at a time to harvest the antibodies. If you tried to get a gallon of blood out of a person, that person would die of blood loss, even after surviving the minor snake bite easily. Bonus: the horse is now safer from snake bites.


Brandon432 t1_ivm0u0o wrote

I’m sure there is something about serum compatibility or physiological similarity to humans, but I don’t know the answer.

We’re not talking about cosmetics testing here. We’re talking about saving human lives. If you want to sign up as the serum factory, more power to you. Otherwise save the indignation for the mink farms.


disgruntled-pigeon t1_ivm0pnh wrote

For the same reason we make vaccines instead of just infecting everyone with a virus. Not everyone’s immune system is strong enough.


firebolt_wt t1_ivmwwpk wrote

Anti venom is an useful medical resource, but do you know which resource is even more needed? Human blood.

No sense in wasting human blood for something you can avoid, specially when a human has around 5 liters of blood total , while a horse can lose 5L and live.


itsybitsybiter t1_ivmzci8 wrote

Plenty of blood mass, easy to handle and house, widely available.

It is possible for a human to immunize themselves against venom by injected low, dilute doses over time. But you risk (1) venom related toxicity, or (2) venom allergic sensitization. It's also just deeply impractical, dangerous in ways medicine does not accept for a reasonable risk to volunteers, and takes a long time to do safely (multiple small doses > one dose)


Ok_Construction5119 t1_ivn8viq wrote

Horses are bigger, can tolerate a higher dose (due to greater muscle mass), and produce more antibodies (in terms of volume, not concentration)


horsetuna t1_ivl7c0n wrote

Some antidotes are made from an immune response... Like an allergy you could say.

One method they used to use was to inject a small amount into a horse, and then take some blood, extract the serum and that's the antidote. I'm told some people can build up an immunity.

It doesn't work with all venoms though, and I believe these days many are synthetic.


Jonnystarr23 t1_ivma4t0 wrote

Thanks for the awesome question and answer. I had no idea how much I wanted this knowledge until I read this 🤣 If I ever decide to go horseback riding in the Arizona desert, I'd like to be on the horse that was used to make rattlesnake antivenom. "Yeah, my ride got bit by a diamondback. Shook it off like a boss!"


groveborn t1_ivn7t2x wrote

Humans are much more susceptible to rattlesnake venom than most of our pets. Almost doesn't bother dogs at all.

Edit: I was relying on information I got from tv, many years ago - turns out we can't trust TV 🤷


BiffJenkins t1_ivnbe9h wrote

Grew up in Arizona. Rattlesnake venom most certainly affects dogs. Like, to death.


m0ibus t1_ivnvrgs wrote

If you had said "funnel web spider" you would have been spot on. Kills people, doesn't bother dogs and cats or mice. Insects and people are the most susceptible. Can't trust TV, but trust stranger on internet with no references.


groveborn t1_ivpyr28 wrote

It's entirely possible that was the message and I'm completely misremembering.

Oh, as to the second point, while entirely deserved, most people in life, and especially on the Internet, provide no sources... And the remaining don't generally check them.


BoldEagle21 t1_ivnivly wrote

I googled how does an antidote work and I think the wiki explains it well; > An antidote is a substance that can counteract a form of poisoning.[1] The term ultimately derives from the Greek term φάρμακον ἀντίδοτον (pharmakon) antidoton, "(medicine) given as a remedy". Antidotes for anticoagulants are sometimes referred to as reversal agents.[2]

> The antidotes for some particular toxins are manufactured by injecting the toxin into an animal in small doses and extracting the resulting antibodies from the host animals' blood. This results in an antivenom that can be used to counteract venom produced by certain species of snakes, spiders, and other venomous animals. Some animal venoms, especially those produced by arthropods (such as certain spiders, scorpions, and bees) are only potentially lethal when they provoke allergic reactions and induce anaphylactic shock; as such, there is no "antidote" for these venoms; however anaphylactic shock can be treated (e.g. with epinephrine).

Here is an example where they are using horses to produce the antibodies for snakes;

TL:DR the horses are given doses of Tiger or Brown snake poison, not enough to kill them but enough to stimulate an immune response. They respond by producing antibodies, blood is collected from the horses and the antibodies are extracted from the blood and purified. This can then be used as an antivenom for snakes in this example.