How can disinfectants kill viruses so easily but they are hard to kill when inside someone
In: Biology
While it doesn’t quite work this way you can think of disinfectants as fire
Fire destroys everything it touches. You wouldn’t want someone to put fire inside your mouth because you have a sore throat, right?
this is the difference between *in vitro* and *in vivo* results.
in vitro is latin for in glass – that is, in a laboratory setting (think petri dishes, test tubes, etc – made of glass). in vitro, disinfectants are great for killing viruses because you have the virus isolated. killing the virus is all they can do.
in vivo is latin for in life. while you can get good info from in vitro results, in vivo is what really matters in the end. disinfectants work great on a pathogen isolated on a petri dish, but you have to consider the effects on the host of the virus (us). turns out that disinfectants are usually pretty good at hurting our insides for the same reasons they’re good at killing viruses. you may know that some harm to the patient is necessary in, for example, treatments where chemo or radiation do a number on the body in the process of getting rid of cancer cells. but putting enough disinfectant in your system to have an effect on viruses you’re hosting is too much harm.
By their nature, disinfectants are harmful to humans inside the body; their purpose is to kill or deactivate biological matter. If you were to drink bleach it’d certainly kill any viruses it came in to contact with. In addition to that, it’d literally burn straight through your body, dissolving all your organs along the way.
That’s the conundrum with fighting off a virus once it’s already inside the body:
1. The amount of self-replicating viral particles is way too large to possibly target them individually.
2. Any solutions which would kill off the viral particles inside en masse would also inherently destroy the body itself.
There are treatments that nebulize disinfectants and introduce them into the body. Hydrogen peroxide for example can be nebulized and inhaled. Just make sure a doctor does this for you. Another example is some types of chemotherapy. Again, only do under a doctor’s supervision.
Your body is made of living cells and are themselves susceptible to being killed by disinfectants.
If you want to kill a virus inside a human you would like to do it in a way that does not kill the human. It is the killed virus but not the human part that is hard.
You kill a virus or bacteria with disinfectants with chemical reactions that destroy their membranes but it works as good on human cells. The skin can survive it because it is tougher then other cells and the outer layer is dead cells but if you ingest or inject it you will kill lots of human cells.
So any simple way would kill the human long before the virus. You for example like an over 60% alcohol in hand sanitizer. A blood alcohol level of 0.5% is classified as “High possibility of death” So the human is dead long before viruses.
For bacteria, you use antibiotics that are targeted and block specific chemical reactions in bacteria that do not occur in human cells. A virus as technically not alive outside of host cells and when it infects a cell it uses the human cells to manufacture copies of it. This make it hard to kill a virus in a human because what they do is injecting RNA in a cell and let is do th work.
So the best way we know to kill viruses in a human is to educate the immune system in how to handle it itself so it knows what antibodies to make, this is what a vaccine does.
Oh they’ll work just fine. The problem is that in order to make sure you reach all the viruses in the body with the disinfectant you would have to inject enough to die a pretty painful death. Disinfectants work great for flat surfaces but body tissue is a whole different issue.
Disinfectants kill things indiscriminately. Anything alive gets killed. Trouble is, humans are in large part *also alive*. If you use the same chemicals in disinfectants inside your body, you won’t just kill the viruses, you’ll kill the you-uses too.
Viruses out “in the wild” on surfaces and in the air are just a protein shell with genetic material inside. It’s very simple to just break down exposed protein and the genetic material into non-working bits of biological molecules. Once a virus is inside a person, however, the virus spends most of its time inside the person’s cells, where their genetic material overrides your own and uses your protein- and genetic material-reproducing mechanisms to create more viruses. It’s really difficult to find and destroy something that is inside your own cells without destroying all your cells and killing you in the process. The only time the virus is exposed is when it leaves your cells, after producing as many copies of itself as it can, and the new viruses move to nearby cells and inject their genetic material. While they’re outside your cells, they can be attacked and broken down by your immune system, but oftentimes your immune system is too slow to get the required virus-destroying machinery to the site, or can’t recognize the virus as a threat.
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