Vaccines against coronavirus – How likely they are to fail

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It is impossible to overestimate the value of developing an effective coronavirus vaccine, which is seen as the shortest and most painless way to get us back to normal. This view is shared by political leaders around the world, who are pinning their hopes on the next day.

However, although clinical trials have already begun and production agreements have been signed, ministers and their advisers have become more cautious in recent days.

Is it possible for the vaccine to fail?

Last week, Britain’s second-largest health official, Jonathan Van-Tam, said words no one wanted to hear: “We can’t be sure there will be a vaccine.”

But he is right to doubt it.

Vaccines are simple at first, but complicated in practice. The ideal vaccine protects against infections, prevents them from spreading and is safe. But none of this is easy to achieve, as it turns out if we look at the usual vaccine schedules.

More than thirty years ago, scientists identified it HIV, the virus that causes it AIDS. To date, we still do not have a vaccine for the disease. The virus that causes dengue fever was detected in 1943, but the vaccine that fights it was only approved last year – and even then there were reservations about making the disease worse for some patients.

The fastest vaccine in history is for mumps. Even so, owning one is still beyond the reach of the average person.

Scientists have been working on vaccines for other coronaviruses in the past, so they don’t start from scratch. Two coronaviruses have caused deadly epidemics in the past, specifically o Sars and Mers. In both cases, there has been research into vaccine development. However, none was completed, as was the case Sars was limited without it, while the Mers never expanded beyond the Middle East. Lessons from this process are expected to help scientists in their current endeavors, but much remains of the information we do not know about the virus.

Possible obstacles

One of the main concerns is that coronaions tend not to develop long-term immunity. About a quarter of the common colds are caused by human coronaviruses, but the immune response recedes so rapidly that the same people can become infected with the same disease the following year.

Researchers at the University of Oxford recently examined blood samples from patients who had recovered and found that antibody levels IgG – those responsible for the longest immunity – they increase a lot during the first month of infection, but then they start to decrease again.

Last week, scientists at Rockefeller University in New York found that most people who underwent coronary artery disease without the need for treatment did not develop many effective antibodies to the virus.

The vaccine could be more effective than a mild infection, but it is not yet possible to know how far it will go. If it ends up providing protection for only a year, the virus is expected to survive for a long time to come.

The genetic stability of the virus is also of paramount importance. Some viruses, such as the flu virus, mutate so fast that they force scientists to create new vaccines every year. Its rapid mutation of HIV is an important factor in preventing the development of an effective vaccine.

So far, the corona seems to be fairly stable, but that doesn’t mean there have been no mutations. Some genetic changes have been identified in the “crown” of the virus’s proteins, which are the basis of most vaccines. If mutated too much, the antibodies that will be developed by the vaccine may not be able to adequately inactivate the virus to prevent infection.

Challenge and security

The rush to create a vaccine cannot bypass the safety rules. In contrast to experimental drugs for severely ill patients, the vaccine may be given to billions of healthy individuals.

This means that scientists will have to be very careful about the signs of serious side effects. During the research on his vaccine Sars In 2004, scientists discovered that one of the candidate vaccines caused hepatitis in weasels. Another agony the virus is more likely to become dangerous because of the antibodies the vaccine will cause. Such virus adaptations have led to severe lung damage in animals who have been vaccinated against it. Sars and his Mers.

How effective will it be?

Many scientists believe that we will soon have some form of coronavirus vaccine. But how effective will this vaccine be?

Those currently being tested have at least eight different approaches. Others use weak and inactivated parts of the virus, which push our body to produce antibodies without having to get sick.

Ideally, a vaccine should produce high levels of long-lived antibodies to destroy the virus, as well as T cells to kill infected cells. However, each vaccine is different from the others and so far no one knows how immune response is sufficient.

Early results from the two most promising vaccines suggest they will be effective to some extent.

In the case of her vaccine Moderna, Twenty-five people developed antibodies at levels similar to those of sick patients.

Another vaccine, this time from the University of Oxford in monkeys, failed to prevent infection but appears to have provided protection against pneumonia, one of the leading causes of death in coronary heart disease patients.

If people react in a similar way, those who are vaccinated will still be able to spread the virus but will be less likely to die from it.

How effective the vaccine will be will determine how it is used. If they have a very effective vaccine in their hands that protects them for many years, countries can seek out herd immunity by vaccinating at least two-thirds of the population.

This is the ideal scenario. Most likely, however, we will end up with several vaccines that will provide partial protection. Vaccines with weakened virus sections can be dangerous for the elderly, but effective for young people with stronger immune systems.

On the other hand, the elderly may receive vaccines that prevent the progression of the disease and not the infection.

But if there is no effective vaccine, the virus will continue to spread and develop, creating more resistant strains that the vaccine will not be able to fight.

So will he survive?

Probably yes. If the vaccine is shown to provide only one year of immunity, the virus is more likely to become endemic.

But even if an effective vaccine is found, eradicating the virus will not be an easy task. This is partly due to its “discreet” symptoms, but also to the fact that in order for coronavirus to disappear, full vaccination coverage must affect the entire planet.

This involves huge amounts of vaccines that need to be given quickly and simultaneously in all parts of the world, leaving no gaps that will allow it to circulate.



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