People who are at risk of severe influenza infection or those who live with such people should be vaccinated annually. It doesn’t work like other diseases where you get a maximum of two or three doses and are vaccinated for life. Or at least for several years. It is impossible to do this in this way, since the virus mutates so much that scientists have not yet been able to develop flu vaccine which serves from one season to the next. They haven’t even managed to make their efficiency the same year after year. There are good years and not so good years. But the fact that it has not yet been achieved does not mean that it is not being tried and that there are no researchers following the right path.
This is the case, for example, with scientists who have just tested a flu vaccine consisting of 80,000 different proteins. The results in these animals were very good, even at a dose of virus that should have been lethal.
This doesn’t mean we can raise the bells in the air now, but it does mean there is room for optimism. Moreover, these are not the only scientists working on a universal vaccine. Other options are already being developed that may even be effective against other viruses like COVID-19, which also forces us to repeat immunizations as new variants emerge. It’s a long distance race and it doesn’t matter who comes first. The main thing is that they come.
Why should you get a flu shot every year?
Viruses can only reproduce in the cells they infect. They don’t have a proper replication mechanism, so they take over ours when they invade us.
At this moment they begin make copies at high speed, as if it were a photocopier. But it is not an error-free copier, and among so many copies it can make mistakes. These errors are changes in the genetic makeup of the virus, known as mutations and can cause three different effects. On the one hand, this may be a neutral effect that does not affect the virus either positively or negatively. They can also harm the virus by preventing it from surviving. These two options go unnoticed by us: some because they do not represent any change in what we already know, and others because they disappear. The problem lies with the third variant, which gives the virus an advantage. For example, this could lead to them being able to infect new species or cause milder disease, making it easier for the infected to interact and infect new individuals.
All viruses do this. However, there are viruses that cause more errors and therefore, they mutate more. This is a case of influenza. This is why it is so difficult to develop a vaccine against them. Vaccines typically target one or more proteins of the virus. They are introduced into the body in such a way that the immune system is prepared to fight them when they arrive with the virus. But what happens if the virus changes so that these proteins are no longer the same as before? It is obvious that the vaccine is losing its effectiveness.
Every year, researchers track the movements the flu makes in your body. Peak season. This allows them to predict to a certain extent what their behavior will be like next season and make a flu vaccine tailored to that. But this is still an approximate forecast, which is sometimes more accurate, sometimes less. Therefore, there are years when slightly larger outbreaks occur, even when a significant portion of the population is vaccinated.
New approaches
There is a lot of research into developing a universal vaccine against the virus. To do this, options such as stimulating the development of RNAi, a molecule capable of binding to the genetic material of the virus and preventing its replication, were tested.
In this new case, they took a more traditional approach, but with crucial changes. There are two envelope proteins of the influenza virus that typically trigger an immune system response: hemagglutinin and neuraminidase. In fact, the strains get their name from the type of each that comes together. For example, the two most famous are H1N1 and H5N1. Viruses have much more of the former than the latter. 5-10 times more. Therefore, it makes sense that this is what vaccines are most likely to target.
It is a protein that is divided into two parts: head and stem. The head is the part that binds to the receptors of the infected cells in order to penetrate them. The rest is what is known as the stem or trunk.
Most often the head mutates. The trunk usually lasts longer. However, precisely because the head is the first to attach to the receptors, the brain recognizes it the fastest. the immune system.
Recognizing this problem, the authors of the just published study deliberately mutated the hemagglutinin protein in different ways. So they got 80,000 proteins with a slightly different head and preserved stem. All of them were introduced into the flu vaccine.
Their goal was that by always introducing the same stem, the immune system would react to it more strongly. This way, in the event of a real infection, there will be a whole battalion of antibodies ready to attack that area of the protein that may not have changed during the season.
Animal testing of influenza vaccine
Currently, this flu vaccine has been tested in mice and ferrets. The latter are not very common as laboratory models, but are very effective in studying influenza because they are sensitive to all strains that infect humans.
The results were very good. Despite the fact that after vaccination they were given a lethal dose of the virus, 100% of mice survived.. Many of them have not even contracted the disease. As for the ferrets, many of them became ill, but in a milder form than without the vaccine.
It should be noted that these were animals that had never been exposed to the virus. People, unless they are newborns, have done this, so it will sum of immunities which will need to be studied later.
There is still a lot of work to be done, and there is no way to be sure that this flu vaccine will be useful for people. But for now, it seems like a good topic for the search for a universal vaccine. Now that bird flu is starting to cause more problems than usual, it’s time to continue this research.
Source: Hiper Textual
