For most bacterial (and even fungal) infections, we’ve developed medications you can take and the infection is gone in a few days.
But most viruses remain completely untreatable. The best we can do is develop treatments that manage the symptoms, or vaccines that boost your body’s natural defense and make it somewhat less likely that you’ll get infected, or if you do get infected it’ll be a less severe case.
The flu, COVID, RSV, swine flu, bird flu, HIV, Ebola, even the common cold. We don’t really have a “cure” for any of them. Why not?
What’s different about a virus that makes it so much harder to just develop a pill you can pop to make it go away?
In: Biology
viruses hijack our cells to reproduce which makes it tough to treat them without affecting our own cells, in contrast antibiotics can target bacteria specifically. That’s why we rely on vaccines and managing symptoms for viral infections
Bacterial infections can be treated by giving you something that specifically kills bacteria and mostly leaves your body’s cells alone. That is what “antibiotics” are, chemicals that are “anti” or against a “biotic” or living thing. Think about it like leaving out poison to kill pests.
Viruses however are often considered to not even be alive. They are just DNA or RNA instructions contained in a protein coating that is arranged like a trap to inject those instructions into your cells. You can’t kill something that isn’t alive; they don’t eat anything and their protein coatings are very durable. It would be like leaving out poison to try to kill landmines. Not very effective.
When the viruses inject their instructions into your cells it takes over their cellular machinery and makes them construct new viruses, spreading the infection. It is hard to attack them in this stage because those cells are still your cells; they look like your other healthy cells to your body so there isn’t any way to attack them without also killing the rest of you. What we *can* do is give medications that slow down the replication of the viruses by interfering with the replication of DNA and RNA, but those have down sides too because our bodies also use DNA. Think about it like clearing a minefield by whipping the ground with chains to set them off. It clears the mines but it also tends to mess up whatever else you had in the field as well.
Bacteria have an active metabolism of their own, they make their own DNA, they consume nutrients, they are capable of reproduction on their own. This makes it possible to poison them with antibiotics to disrupt their life processes, slow their reproduction, and allow our immune system to finish them off.
Viruses have no metabolism of their own, they just hijack the metabolism of their host to get reproduced. Antibiotics that are deadly to bacteria have no effects on them.
I work in the pharma industry, not specifically with antivirals, but I have a bit of knowledge.
There are two factors at play.
To kill off a disease, you basically need to find a poison that works on the disease, but not on the host. Weakening the host would just make things worse.
For bacteria and fungi, they’ve evolved a lot of traits not shared by animals. So it’s very easy to make something that screws up, say, their cell walls, which animals don’t have. You don’t even need to narrow down the species too hard because many of these traits are shared by multiple families.
Viruses are just a string of DNA or RNA in a protein shell, which are the same basic building blocks that we’re made of, they don’t have any complex structures. You’d have to be extremely carefully specific to engineer something that targets a virus and not a human.
The second factor is that viruses aren’t alive. What I mean by this is that, when they’re outside of a host cell, they don’t do anything, and they don’t NEED to do anything. With a bacteria, all you need to do is pop its little membrane, or give it a little microbe heart attack, and it’ll die, rendering it harmless and ready for cleanup. For a virus, there’s nothing you can do to easily “kill” it, the only death it has is physical destruction. And the drugs that can do that would be very dangerous to pump into your bloodstream.
There are a variety of antiviral drugs on the market, but due to their complexity and specificity they can be pretty expensive. They can’t “kill” the virus directly, instead they’ll typically glob onto it and try to impair it as much as they can in hopes of stalling the infection and giving the immune system more time.
Viruses aren’t alive. They are more like software on a usb drive. The software runs on your cells. Which means the only part of the system that’s alive. Is you? How do you kill you?? In fact this is what your immune system often does – it kills your own cells.
Bacteria contain a lot of molecular machinery that is unique to them and completely distinct from eukaryotic life. These make nice targets for antibiotics which would have little crossover to mammalian cells. But viruses have no machinery. They hijack our cells machines to replicate, which means we don’t have a clear target. Viruses do make some unique proteins, such as their own reverse transcriptase, which they need to replicate. We can target that, but it has some homologous with our transcriptase proteins, making selectivity and issue again. Basically, because a virus is so simple, it’s hard to target.
The common cold isn’t one virus. I think it’s common -hahah- knowledge that there are more than 200 of them. Viruses tend to mutate. By the time you’ve defeated one, there’s another version out there.
I didn’t know if I would call Fungal Endocarditis (fungus on heart valves) easy to kill but it is alive so it is killable. All of these infections point to the value of prevention: clean needles, masks, washed hands…
i am a person not qualified to answer but here is my take.
virus are like mechanical faults gene altering like gears with missing teeth. wires connecting to the wrong port.
bacteria on the other hand are organic creatures like that pesky rat chewing on your cables . or dog peeing on your carpet. some times bacteria are harmless but their poop are toxic chemicals.
that is to say you can kill the rat, you can mop the floor ( damage done by bacteria )
but you need to change out circuits or replace gears which are difficult ( virus )
correct me if the layman me is very wrong
Tney are harder to treat because they use your own cells to reproduce. Some retroviruses (like HIV) actually modify your cell’s DNA directly meaning the only way to stop the virus is to kill the cells with the modified DNA. Otherwise those cells just keep making more HIV.
Latest Answers