Why is influenza so difficult to treat?

Some time ago, the flu virus was rampant, and some celebrities and well-known media people died from the flu. Many netizens were puzzled. With the development of medicine, why is there no way to cure the flu virus and can only use auxiliary means to relieve the pain of patients? If it can be completely cured, the flu will not be so rampant...

Is it because the virus is too cunning or because medicine is not advanced enough? In fact, it is because you accidentally kill yourself. Today, let's talk about why this happens.

01. Why is the influenza virus so difficult to kill?

First, cold viruses are highly variable and unpredictable. The viral genome mutates very quickly, especially the influenza virus, which mutates every year and new strains emerge. This makes it possible for drugs developed for specific virus strains to quickly become ineffective because new virus strains may become resistant to existing drugs. In addition, the mutation of the virus also increases the difficulty of drug development. Scientists need to constantly track the mutation of the virus and adjust drug development strategies in a timely manner.

Secondly, the replication and transmission mechanism of the cold virus in the human body also increases the difficulty of treatment. After the virus enters the human body, it will use the cell replication mechanism to replicate in large quantities and spread in the human body through various pathways. This makes the virus widespread in the human body and difficult to completely eliminate. Moreover, while antiviral drugs kill viruses, they may also cause damage to human cells, so it is necessary to find a balance between efficacy and safety.

Furthermore, the treatment of cold viruses is also subject to the cost and benefit of drug development. Since colds are usually a self-limiting disease, most patients can gradually recover through the resistance of their own immune system. Therefore, for the treatment of cold viruses, drug development institutions may be more inclined to develop drugs that can relieve symptoms and improve patient comfort, rather than directly treat the virus itself. In addition, the development cost of antiviral drugs for cold viruses is high, and the market life is relatively short, because new virus strains may appear quickly and cause the drug to fail.

02. Why would you accidentally kill yourself?

To discuss this issue, let's take the H1N1 influenza virus as an example.

The influenza virus genome is 13158 long (8 fragments spliced ​​together). About 10% of the human genome is viral sequences. The human genome is about 3 billion long, so 10% is 300 million long. If you use drugs to target a viral genome of about 10,000, you may accidentally encounter the 300 million viral genome sequences stored in the human body. Then it's game over.

03. Let’s test the influenza virus

To test the flu virus, I found a popular virus, the 2009 H1N1 virus, which spread around the world in 2009 and caused many consequences (the following is a random test, you don’t need to read it)

H1N1_Swine Flu_Influenza A (H1N1) Spreads Globally_NetEase News

This is the genome information of the H1N1 virus

(2009 H1N1 virus genome size)

I downloaded the sequence and compared it with the biological database (NCBI).

What do you guess?

The above picture shows the comparison result (after all, it is across species, so the comparison effect is average), but some of them are still compared.

It has something to do with human potassium channel tetramer.

In this case, how to use medicine?

04. It is not easy to kill the virus, but to prevent its spread

The virus itself is similar to dormancy, and its core substance is a very short nucleic acid (except for prions). After it enters the human body, it gives orders to the cells and mobilizes the cells' own production tools to replicate themselves.

There are seven steps in the HIV replication process, and one of the functions of blocking drugs is to prevent its further spread.

What would you do in this situation?

Therefore, when killing a virus, we usually stop the cells when the virus is multiplying, and then wait quietly for the cells to die.

ref.

National Center for Biotechnology InformationInfluenza Virus Database Home.