Technically, the hand sanitizers target virions, not viruses. Virions are the form of the virus that exist outside of our body. They have a special protective coat that keeps them healthy in the outer world – a naked virus is very delicate.
When the virion enters the body and uncoats itself (like people take off their coat when entering inside your house) then it’s known as a virus. After uncoating, the virus no longer conceals its weapons such as its proteins (kind of like knives and guns) and DNA or RNA (sort of like high-tech computer weaponry). Using these weapons, it attacks and takes over cells in the body, holding them hostage until your body’s police force (the immune system) is able to step in and stop it.
What a great houseguest, no?
So, to answer your question: hand sanitizers target the coat of the virion. They cut and shoot holes into the coat. But if the virus has invaded your body (your home), these same chemicals aren’t very useful because they have already de-robed and made their way inside your cells. Plus, you couldn’t inject a hand sanitizer anyway because today’s sanitizers are made from concentrated alcohol that would kill you if put in the blood.
But think about it. If an intruder is outside of your home, it’s very easy to arrest them or shoot them without harming you. But if they have taken you hostage, and are holding you at gunpoint so to speak, it’s much harder to stop such a complex situation. It’s also very difficult to harm the intruder without also harming you by accident. This is one of the key reasons why so many antiviral medicines taken by mouth are either ineffective or cause many side-effects.
So hand sanitizers can be useful for virus protection but are not designed for hostage crisis situations.
Answer by Artem Cheprasov
Question from @pstni via Twitter