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Viruses vs Bacteria / Antivirals vs Antibiotics. The difference?

Viruses vs Bacteria / Antivirals vs Antibiotics. The difference?

Image by Steve Buissinne from Pixabay

While they can both make you sick, as well as both help with various factors in your body (such as digestion), these two are quite different. Let’s first start by defining what viruses and bacteria even are.

What are bacteria?

Bacteria are single-celled microbes that do not contain a nucleus or membrane-bound organelles. There are 5 structural types of bacteria, each one determined by its shape: spherical (cocci), corkscrew (spirochaetes), rod (bacilli), comma (vibrios), or spiral (spirilla). They can form chains and clusters and can be in pairs or alone.

There are about 10 times more bacteria in the human body than there are human cells. This is because they are much smaller than human cells. Bacteria are vital in human digestion, helping to break down carbohydrates and short-chain fatty acids so that the body can absorb them. They most often cause disease when a single species dominates the gut ecosystem, which tends to follow the prolonged use of antibiotics.

What is a virus?

A virus is an infectious replicating agent, a parasite, that contains strands of DNA or RNA surrounded by a protein coating. Viruses place their genetic information into a cell where it may get incorporated into the genetic code of the cell or it will only use the cells machinery (i.e. ribosomes and enzymes) to make more copies of them. This method is how viruses spread.

Unlike bacteria, a virus is not a living cell and is unable to survive without a host. They are much smaller than bacteria and are far more common, outnumbering bacteria 10:1.

Despite often causing harm, it is believed that viral DNA/RNA is vital when it comes to biodiversity. In fact, 8% of the human genome is thought to have come as a result of viral DNA.

What is the difference between an antiviral and an antibiotic?

As you might have guessed, antibiotics do not work on viruses and vice versa. Some doctors might prescribe an antibiotic if you are sick, without knowing if you have an infection, or something like the common cold (caused by rhinoviruses and sometimes coronaviruses).

This is because the symptoms of both are very similar. For instance, a sore throat can be caused by a virus but so can streptococci (the bacteria that causes strep throat). Whooping cough is caused by bacteria, while bronchitis can be caused by both. So quite often, unless a doctor tests for the strain of the bacteria/virus, it is unknown whether antibiotics will even work. All that said, doctors may prescribe antibiotics in clinical settings to prevent a secondary infection from occurring due to a compromised immune system after battling a serious viral infection. This treatment is not infrequent in patients recovering from severe Covid-19 for instance.

Antivirals work by either eliminating the virus or preventing the virus from spreading. For instance, they might target specialized proteins or other parts of the virus to prevent it from being able to grab ahold of a cell. These are often only effective when administered before exposure, or shortly after exposure before symptoms occur, giving your body time to defend against the intruders. They are mostly ineffective if you are already sick.

Antibiotics work to interfere with the reproduction of bacteria. This prevents bacteria from spreading, giving your body the ability to fight them off. However, overuse of antibiotics can cause major issues, like the overgrowth of certain strains of bacteria over others, as well as the bacteria developing a resistance to the drugs.


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