Sunday, June 13

Can a universal vaccine be created that protects us against all coronaviruses?


“A bug, a medicine.”

Among health scientists, this is a common phrase to refer to a traditional way of working: every time a new disease arises, they try to develop a treatment, a drug or a vaccine to specifically combat that ailment.

This is what happened with SARS-CoV-2, the coronavirus that causes the disease COVID-19.

On Record time, scientists in various parts of the world they developed vaccines that protect people against that particular virus.

That was a wonderful achievement of science, but it has at least three limitations.

The first is that mutations that generate new variants of the virus can at some point decrease efficiency from vaccines, or even escape the immune response they produce.

The second is that SARS-CoV-2 is just one of at least seven types of coronavirus known to affect humans.

And the third is that situations like the destruction of natural habitats and the human advance towards wild territories, increases the interaction between humans and animals, which increases the chances that an animal coronavirus will pass to people.

For reasons such as these, scientists agree that it is highly likely that the world will once again face a crisis in the future. new coronavirus epidemic.

That risk has led several researchers, even before this pandemic, to have been looking for a universal vaccine that can combat several, including all coronaviruses that affect humans, and the variants that exist or may come into being.

It would be a powerful vaccine “Pancoronavirus”.

Then we would no longer be talking about a vaccine for a single bug, but a vaccine for many critters.

What is this approach and how feasible is it for a pancoronavirus vaccine to become a reality?

vaccine
Vaccines against COVID-19 were manufactured in record time. (Photo: Getty)

The coronavirus family

Coronaviruses are a family of viruses that share one characteristic: the corona, a protein in the form of spike that they use to infect the cells of the body where they are hosted.

There are four types of coronaviruses: alpha, beta, gamma, and delta.

Among them, there are seven that can infect humans, according to the Centers for Disease Control in the United States.

And among those seven, there are three from the beta group that have caused epidemics in recent years, according to data from the Health Organization (WHO):

  • MERS-CoV, which causes Middle East Respiratory Syndrome (MERS). It was first identified in Saudi Arabia in 2012. As of March 2021, 2,574 cases of MERS have been confirmed, including 885 deaths.
  • SARS-CoV, which causes Severe Acute Respiratory Syndrome (SARS). It was first identified in China in 2003. During that outbreak, 8,098 cases were recorded, including 774 deaths.
  • SARS-CoV-2, which causes COVID-19. Identified in China in 2019, as of April 28 it had infected nearly 150 million people, including more than 3.1 million deaths.

“Relatively easy”

Today, several laboratories are developing initiatives to manufacture universal vaccines against coronavirus.

The rapid development of vaccines against SARS-CoV-2 is a sign that perhaps don’t be so difficult achieve it, according to specialists.

One of the reasons is the spike protein.

When this protein attacks a cell, it causes some neutralizing antibodies that adhere to the virus and prevent it from infecting the cell.

Until now, it has been relatively easy for SARS-CoV-2 vaccines to stimulate the development of these neutralizing antibodies.

These antibodies have the ability to act on different variants of the same virus, and could be used to design vaccines that act against several members of the same family of viruses, as is the case of the betacoronavirus.

vaccine
SARS-CoV-2 has certain advantages for vaccine development. (Photo: Getty)

Furthermore, SARS-CoV-2 has so far not shown a strong ability to evade the immune response and the action of neutralizing antibodies, Dennis Burton and Eric Topol, researchers in immunology and molecular medicine at the Scripps Institute, explain in a paper. of the magazine Nature.

This represents an advantage over other viruses such as influenza or HIV, which have high capacity to produce variants that allow them to escape the immune response.

That is one of the reasons why an HIV vaccine has yet to be approved; and why every year it is necessary update the flu vaccine.

Another encouraging sign comes from SARS survivors, a recent magazine article explains. Science.

In laboratory tests, it has been shown that the antibodies these people developed can also block SARS-CoV-2 infection.

With that background, compared to flu and HIV, develop a pancoronavirus vaccine “It will be relatively easy”, optimistically says Barney Graham, deputy director of vaccine research at the US National Institute of Allergy and Infectious Diseases (NIAID), cited by Science.

Graham was also involved in the development of the Modern company’s COVID-19 vaccine.

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All coronaviruses have the spike protein. (Photo: Getty)

One against all

So far, no pancoronavirus vaccine candidate has been tested in humans.

However, “In one or two years we are going to have many results”According to Dr. María Elena Bottazzi, co-director of the National School of Tropical Medicine at the Baylor College of Medicine in Houston and co-director of the Center for Vaccine Development at Texas Children’s Hospital in the United States, tells BBC Mundo.

In 2016, Bottazzi worked on a possible pancoronavirus vaccine, but by then SARS and MERS had ceased to be an emergency and other priorities emerged such as Ebola and Zika. For this reason, he did not have the resources to continue with his investigations.

According to Bottazzi, the development of a pancoronavirus vaccine is a I work in etapas.

First, one can aspire to achieve a vaccine against all variants of COVID-19.

It can then be expanded so that the vaccine covers all betacoronaviruses, or even alpha viruses as well, which can also infect humans.

Finally, it could come to predict virus sequences to develop vaccines that cover all coronaviruses.

“The ideal would be a vaccine that covers all the coronaviruses that are present in humans,” says Bottazzi, “but also predicts what another coronavirus might be that is going to cause an outbreak.”

In search of the vaccine

According to Bottazzi, there are two ways to make a pancoronavirus vaccine.

One option is to develop several individual vaccines, called monovolants, that target a specific coronavirus, and then combine several monovalent vaccines to achieve a single one. polyvalent vaccine, which acts on various types of coronavirus.

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A pancoronavirus vaccine could help fight a future pandemic. (Photo: Getty)

This is the technology used, for example, in the pentavalent vaccine that protects children against diphtheria, pertussis, tetanus, polio and infections caused by Haemophilus Influenzae type b.

The other option is to find a genetic code that is sufficiently representative of coronaviruses, from which a universal vaccine can be created.

Once any of these vaccines are achieved, laboratories and pharmaceutical companies should evaluate whether they produce them and have them in stock for when they are needed.

Another possibility is not to manufacture them completely but to advance in the safety and efficacy studies and, if the threat of a pandemic occurs, to start manufacturing them from the path that is already advanced.

The right moment

Given the impact of covid-19, the development of a pancoronavirus vaccine has become very relevant.

In November 2020 the NIAID opened a emergency call to provide funding for pancoronavirus vaccine manufacturing projects.

In March, the Coalition for Epidemic Preparedness Innovations (CEPI), a non-profit organization working in partnership with WHO, announced a $ 200 million fund to speed up investigations in the development of vaccines against betacoronaviruses.

According to the magazine ScienceCurrently in the world there are more than 20 research teams working on a candidate for a pancoronavirus vaccine.

According to CEPI, several of these initiatives look promising in principle.

One of them is the colaboration between the University of Nottingham, Nottingham Trent University and the pharmaceutical company Scancell.

His bet is for a vaccine that acts on the spike protein and on another structure of the virus, called protein N.

This N protein is much less prone to mutating, so if the vaccine manages to act on it, it could generate an immune response regardless of whether the spike has mutated.

In that way, it could offer protection against various types of coronavirus.

virus
Several teams are working on the development of a pancoronavirus vaccine. (Photo: Getty)

CEPI also highlights the project of the California Institute of Technology, where they are working on a vaccine “All in one”.

This prototype consists of using a nanoparticle that supports fragments of the spike of various coronaviruses.

In laboratory tests in February, this method showed that it can generate antibodies against various types of coronavirus.

China and Cuba are also working on a joint project to develop a universal vaccine they have called “Pan-Corona”, as reported by the EFE agency.

The technique of this candidate consists of combining fragments of different coronaviruses, in order to generate an immune response that acts on all of them.

For now, “The urgency is to finish attacking COVID-19”Bottazzi says, but at the same time, she says that she and the other research teams work in a multitasking to achieve a pancoronavirus vaccine to help prevent a next pandemic.

“We must not think that by solving the COVID-19 crisis we will be out of the problem,” concludes Bottazzi, “we have to continue looking for alternatives for any emergency.

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