In any corner of the earth where life exists, there will be viruses, viruses rely on other life to survive and reproduce, they are between life and non-life, simple enough to leave only a piece of genetic material, wrapped in a protective protein shell.
But viruses have a far greater impact on life on Earth than you might think, with at least 8 percent of human DNA coming from remnants of ancient viruses that may have infected human ancestors at some point, but eventually some of their genetic material was incorporated into human DNA.
In addition to "modifying" organisms at the genetic level, they also affect the behavior of organisms in the short term.
Illustration: Human migration routes
Humans originated in Africa, and about 15,000 years ago, humans migrated to all land except Antarctica, but what drives human migration?
All we can think of is that as the population grows, we are forced to migrate for subsistence resources, but there is another possibility - that is, to escape infectious diseases, or in some cases to avoid viruses.
In fact, human fear and avoidance of infectious diseases are carved into the bones, and sometimes we are even afraid of harmless things that seem to bring about diseases.
Now, we've built cities and isolated all the bad stuff on the periphery of the city, but we haven't gotten rid of the virus, and this NEW CROWN is the best example.
If living things have their own natural predators, then the natural enemies of those who stand at the top of the food chain are likely to be viruses, including humans.
In 1918, the Spanish flu that broke out during the First World War swept the world in a short period of time, which was the first worldwide pandemic and the most serious in the history of human infectious diseases.
Image note: Spanish influenza data map
Statistics show that the number of deaths caused by the epidemic may exceed 100 million, and the global population at that time was only 1.7 billion.
However, the number of direct and indirect deaths caused by the First World War is almost 16 million, far less damage than the virus, and from the perspective of lethality, it is not an exaggeration to say that the virus is a natural enemy of mankind.
We know that in addition to viruses, infectious diseases can also be caused by bacteria or fungi, but why is it so difficult to control only viruses?
Why is it so hard to find anti-virus drugs?
You will find that we have many drugs on the market for bacterial infections, but it is difficult to find specific drugs for viral infections, in fact, the reason is that viruses are indeed more difficult to deal with than bacteria.
Bacteria are independent life forms that are structurally similar to our cells and can survive independently without host organisms, but they also have many characteristics that humans do not have.
Because of this, we can construct bactericidal drugs based on these characteristics that we do not have.
Structural model of penicillin, Source: Mrjohncummin
For example, penicillin, the reason it works is because it interferes with the construction of the bacterial cell wall, but no cell in the human body has a cell wall, so penicillin can inhibit the growth of bacteria but can not affect the body's cells.
Unlike bacteria, viruses cannot reproduce independently outside the host cell ("replication" may be more appropriate here), they need to hijack the host cell as a place to survive and reproduce.
Obviously, as far as independent survivability is concerned, the virus is completely killed by bacteria, and it can even be said that the virus has basically no independent viability.
Note: Influenza virus
But their relationship with host cells makes it difficult to kill them alone and keep host cells alive.
Since many viruses do not directly kill the cell after entering the cell, they enter the incubation period, they slowly replicate inside the cell and then quietly leak and infect other cells.
So, there are some antiviral drugs (antiviral drugs are available) that can control their infection by interfering with the replication of viruses, but unfortunately, most of the time doing so will also inhibit the replication process of host cells, in other words, this drug is also toxic to infected people.
In fact, the more dependent the virus is on host cells, the more difficult it is for antiviral drugs to function.
In addition, viruses do not have a simple classification like bacteria, different bacteria can find many similarities, but different viruses have unimaginable differences, which means that it is difficult to find a specific drug that can deal with multiple viruses.
Are viruses natural enemies?
In fact, using drugs against bacteria can only bring short-term benefits, bacteria resistance will continue to increase, and eventually the drug will fail, so now the use of antibiotics has been criticized, and many people are worried about creating superbugs.
Fortunately, there are now some more reasonable solutions, that is, biological control, in other words, the natural enemy of bacteria can be used to control bacterial infections.
The "natural enemy of bacteria" that biologists can now find is the bacteriophage — in fact, the virus that can infect bacteria.
Phage T4 infecting bacteria, Source: Guido4
Organisms have evolved to get rid of various natural enemies, but it is really difficult to get rid of viruses, and in a sense viruses are natural natural enemies of all living things.
There are some viruses that can infect bacteria and inhibit the reproduction of bacteria, but they have no effect on humans, which is really a natural "antibacterial drug", and there are basically no side effects.
So, can viral infections be treated in a similar way?
Note: Bacteriophages
The simple answer is that viruses also have biological predators, but it is difficult to deal with their infections in a biologically controlled way.
While it's hard to call viruses life, as we said before, they still have protein coats and NDA, which means they're rich in phosphorus and nitrogen, which is a nutrient for many lives.
Therefore, it has been found that many protosuniced organisms "prey on" viruses, but they prey on basically the phages we mentioned earlier, and perhaps only these viruses are closely related to protists.
However, it is basically impossible to treat viral infections with protozoa, or for that reason, viruses are closely related to host cells in our bodies, rather than being exposed to predators.
Picture note: Chickenpox virus
However, there is one virus that can also infect other viruses, and these viruses are called virions, and the virions are the same as the bacteriophages we mentioned earlier, they use other viruses to replicate and affect the replication of other viruses.
However, it is also difficult to use them as antivirals, because these virions only infect giant viruses, and for those virus diseases that are not very large, they are rarely found.
At last
Although viruses "disguise" themselves as even life, there are still life that will prey on them, but for their infection, it is really difficult to deal with, which is determined by the relationship between them and the host cell.