why is it so hard to make a virus killing drug?
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Viruses aren’t alive in the “drug can kill them” sense. They’re just complicated balls of proteins and DNA floating around. You can’t kill what isn’t alive, the only thing you can do is destroy it. Unfortunately, any chemical that destroys random proteins and DNA will also kill…you.
So the only thing you can do is design a *very* specific molecule that is exactly matched to the virus proteins and nothing else. Which is exactly what your immune system does, but it takes time and it’s very very specific to one particular virus…it won’t work on anything that doesn’t have matching proteins.
Basically, every virus would need it’s own drug and that drug would be stupid complicated…manufacturing protein drugs is very difficult, they’re really big complicated molecules. It’s *far* easier to keep you alive while your immune system figures it out, or train your immune system in advance (this is what vaccines do).
I think it’s easier to explain it this way
We found bacteria killing drugs completely by accident.
Antibiotics were discovered by Alexander Fleming in 1928 while studying bacteria for strep. He returned from holiday and noticed mold growing on the petri dish and the bacteria wasn’t growing near it. He put two and two together and with some work was able to isolate the compounds mold were making to kill the bacteria.
This discovery completely changed medicine.
We do have effective anti-viral drugs but nothing on the scale as effective of antibiotics.
Viruses are a completely different animal than bacteria (not literally, they aren’t animals) as they are tiny balls of protein that can’t even replicate by themselves. Anything we can make that stops those proteins will probably also kill you.
We are actively researching this, but we haven’t had that crazy aha moment yet.
But on the other side we do in fact have an extremely effective way of defeating viruses, vaccines.
Our own immune system is extremely good at fighting viruses, and with a bit of training from a vaccine we can achieve immunity or at the very least not suffer nearly as bad from the disease.
Vaccines are arguably an even more important discovery in terms of medicine than antibiotics.
Unfortunately the vaccines creation techniques we have aren’t effective against all viruses… yet
Antibiotics target weaknesses in bacteria. Viruses have weaknesses too, but they’re also sneaky because they need to get their DNA/RNA inside of us to multiply.
The parts of the cell our body uses to make more proteins (ribosomes) are the same parts that a virus will use to make more of itself. If we use a drug that hurts ribosomes, the virus won’t be able to multiply… but then our cells can’t use it, either, which hurts us.
The best antivirals keep viruses from entering our cells in the first place, but because there’s a lot of different ways to enter a cell, it’s hard to make an antiviral that can be used for lots of different viruses.
Some viruses (retroviruses) also hide inside your cells. They put a copy of their genes into the DNA of a cell; think of the DNA in our nucleus as a “master copy” of instructions to make everything the cell needs. We make usable copies from this master copy and feed these copied instructions into a little machine that churns out proteins (ribosomes). Sometimes, the viral DNA is copied and brought to the protein-printer, and our cells unknowingly print out new proteins that will form a new virus particle.
Because copies are made instead of tearing out DNA, the viral DNA is never removed and can keep being used to make new parts for viruses. We also have a lot of cells, so we can’t get rid of all of the ones with viral DNA because we don’t have a way to know which ones are which. And we can’t actually remove viral DNA from cells… yet. Some technologies are inspired by the abilities of viruses and can be used to make changes to your cell’s DNA, but these technologies are still expensive and not approved for medical use yet.
What if we make fake “cells” that attract viruses. Viruses would prefer to attach to this cell than real cells, and when they injected their genetic materials into these fake cells, they’re trapped and unable to multiply. Big f you to all those pesky viruses.
Viruses hijack the cellular mechanism used to build required proteins, and feed new instructions (the viral DNA) to replicate the virus as many times as possible before the cell dies. It is very difficult to stop that process without interfering with the required cellular activity needed to keep the cell and body working.
However, there are antiviral drugs. For HIV and Hepatitis B, the antiviral drugs are nucleotide/nucleoside analogs – the virus includes a transcriptase enzyme that reads the viral DNA and replicates it by grabbing nucleotides in the cell. These analogs get grabbed by the viral transcriptase because they look/function like a real nucleotide/nucleoside, but they actually terminate the strand before it is complete. If you keep enough of these nucleoside analogs in cells, you can restrict or prevent viral DNA replication without impacting normal DNA transcription too much. Some analogs are preferentially selected by the viral transcriptase, but not all.
For viruses such as HIV/HepB, this means the antivirals are very good at controlling the virus, but not getting rid of it entirely.
We can do that it’s really simple. The unfortunate part is that it will also kill the patient. We don’t want that.
So we must make something that will kill the virus faster than the human. That’s how chemotherapy works, we are trying to kill the cancer faster than the procedure kills the patient.
Ideal drug would be harmless to humans, but that’s really hard as most things that kill virus kill us as well.
its easy to design a drug that “kills”(destroy is the term) a virus, its hard to make a drug that ONLY destroys the virus and not you with it.
Viruses arent much more then balls of protein and DNA, its easy to design a drug to destroy protein and DNA. problem is, humans are also have proteins and DNA so a drug that isnt designed SPECIFICALLY to only interact with the specific proteins of a virus and nothing else is hard, especialy as every virus has their own “Pattern” and needs its own special drug.
imagine you play jenga and need to remove a specific block, its easy to do that by simply destroying the entire tower, thats randomly killing Protein and DNA, but only removing the one block is difficult. also every block has a different shape and needs a different technique to remove
a Vaccine using the same analogy is just asking someone else to do it after you show them how its done via a more loose block(the vaccine) and that person being REALLY good at learning how to remove this VERY specific shape.
It takes a lot of research, time and money to develop a drug that can defeat a virus. Any drug that can do that, has to be made specifically for that strain otherwise it can cause the person more damage than the virus itself
Even if a drug was developed for a virus, by the time it was released and passed all clinical trials the virus may have mutated and the drug is either less effective or not effective against the current strain
Vaccines are the better way as they give your immune system a small taste of what the virus is like, so that it can prepare itself and know how best to defeat it if you get it
Think of it like your bodies antibodies as a defending force of soldiers against an invading army
No drugs or vaccine means you have to fight them off, not knowing what to expect or how to effectively fight them but they can win (you might be sick for a little while)
A drug would be reinforcements but they only know how to defeat soldiers with swords and nothing else. If the invaders have changed tactics (mutated) they might use spears instead so the drugs are useless.
A vaccine would be a small amount of invading soldiers that your antibodies can defeat easily and they now know how to protect themselves
Pharmaceuticals companies would, if possible, focus on vaccines rather than spending more money and research into drugs that can be less effective
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