Could a Single Vaccine Work Against All Coronaviruses?

The invention of the Kovid-19 vaccines will be remembered as a milestone in the history of medicine, made over a few months that took a decade. But the director of the Emerging Infectious Diseases Branch at the Walter Reed Army Institute of Research in Silver Springs, Drs. Kevon Modarjad is not satisfied.

“It’s not fast enough,” he said. more than 2.3 million people The world has died, and many countries will not have full access to vaccines for a year or two: “Fast – really fast – it’s happening there one day.”

There will be more coronovirus outbreaks in the future. Bats and other mammals are rife with this abundant strains and species Family of viruses. Some of these pathogens will inevitably spread at species barrier and cause new epidemics. it’s only a matter of time.

Dr. Modrzad is one of several scientists calling for a different type of vaccine over the years: one that could have worked against all coronaviruses. Those calls were largely ignored until Kovid-19 demonstrated how destructive coronaviruses can be.

Now researchers have started developing prototypes of a so-called panoronovirus vaccine that, if something promising, quickly Results from experiments on animals. A professor of molecular medicine at the Scripps Research Institute in San Diego, Drs. Eric Topol believes that scientists should immediately get involved in another large-scale vaccine-making project.

“We have to get a real workforce to accelerate this, so we can do it this year,” he said. Dr. Topol and Dennis Burton, a Scripps immunologist, asked for it Project on Comprehensive Coronavirus Vaccine On Monday in the journal Nature.

After coronaviruses were first identified in the 1960s, they did not become a high priority for vaccine manufacturers. For decades it seemed as if they only cause mild colds. But in 2002, a new coronavirus called SARS-CoV appeared, causing severe acute respiratory syndrome or a fatal pneumonia called SARS. Scientists scramble to make vaccines for this.

Since no one had previously produced a coronavirus virus vaccine for humans, there was a large amount to know about its biology. Eventually, the researchers chose a target for immunity: a protein on the surface of the virus, called a spike. Antibodies that stick to the spike can prevent coronoviruses from entering cells and prevent an infection.

Public health officials in Asia and elsewhere, however, did not wait for the invention of a SARS vaccine to work. His quarantine and other efforts proved to be remarkably effective. Within a few months, he wiped out the SARS-CoV, with only 774 deaths on the way.

The risk of coronavirus became even more pronounced in 2012, when another species spread more than bats, causing another fatal respiratory disease called MERS. Researchers began work on MERS vaccines. But some researchers thought that if creating a new vaccine for each new coronovirus – then Drs. Modarazad called it “One Bug, One Drug Approach” – it was the smartest strategy. Wouldn’t it be better, they thought, if a single vaccine could work against SARS, MERS and any other coronavirus?

This idea did not go anywhere for years. MERS and SARS caused relatively few deaths, and were soon eclipsed by outbreaks of other viruses such as Ebola and Zika.

In 2016, Maria Elena Botazzi, a virologist at the Baylor College of Medicine, and her colleagues applied for support from the US government to develop a panoronovirus vaccine, but did not receive it. “He said that Panorona is not interested,” Dr. Botazzi said.

His team also lost money to develop the SARS vaccine, as they showed that it works in mice, was not toxic to human cells and could be manufactured on a large scale. A coronovirus that disappeared from view was simply not a top priority.

Without enough money to start clinical trials, the scientists stored their SARS vaccines in a freezer and moved on to other research. “It’s been a struggle,” Dr. Botazzi said.

Dr. Matthew Memoli, a virologist at the National Institute of Allergy and Infectious Diseases, sees those decisions as a gross mistake. “This is a failure of our system of science,” he said. “Funders chase shiny items.”

Three years later, a third dangerous coronavirus appeared: the SARS-CoV-2 strain that causes Kovid-19. Although this virus has a much lower lethal rate than its cousin, which causes SARS and MERS, it does a better job of spreading from person to person, resulting in more 106 million documented cases Climbing around the world and still.

Whatever the researchers had learned about coronaviruses helped them move quickly to create new vaccines for SARS-COV-2. Dr. Botazzi and his colleagues used a technique created to produce SARS vaccines for Kovid-19, which are now in early clinical trials.

Other researchers used new methods to move faster. The German company BioNotech created a genetic molecule called messenger RNA that encoded the spike protein. Partnering with Pfizer, the companies gained US government authorization for their vaccine in just 11 months. The previous record for a vaccine against chickenpox was four years old.

Although the Kovid-19 pandemic is still far away, many researchers are calling for the preparation of the next deadly coronavirus.

“It’s already happened three times,” said Daniel Hoff, a virologist at St. Louis University. “It is likely to happen again.”

Researchers at Cambridge-based VBI Vaccines took a small step towards a panoronovirus vaccine last summer. They made virus-containing shells with spike proteins from three coronaviruses caused by SARS, Mars, and Kovid-19.

When researchers injected this three-spike vaccine into mice, the animals produced antibodies that acted against all three coronaviruses. In short, some of those antibodies can also land on a fourth human coronavirus that causes seasonal colds – even if the spike proteins of that virus were not included in the vaccine. Scientists have Made this data public But it has not yet been published in a scientific journal.

VBI Chief Scientific Officer David Anderson said it is unclear why the vaccine worked this way. One possibility is that an immune cell presenting with multiple versions of a protein at once does not produce antibodies against just one. Instead, it forms a compromised antibody that works against all of them.

“You’re educating it,” Dr. Anderson said, though he cautioned that it was speculation for now.

Last month, Pamela Bjorkman, a structural biologist at Caltech, and her colleagues Posted on More extensive experiments with a universal coronavirus vaccine in Science Journal. Researchers linked the spike protein tips from only eight different coronaviruses to a protein core, known as a nanoparticle. After injecting these nanoparticles into mice, the animals produced antibodies that could bind to all eight of the coronaviruses – and four other coronaviruses that scientists had not used in the vaccine.

Dr. Moderjard is leading a team of Walter Reed, in which another vaccine based on nanoparticles made of protein fragments has been developed. They are projected to begin clinical trials on volunteers next month. Although the vaccine currently uses only protein fragments from SARS-CoV-2 spikes, Drs. Modarzad and his colleagues are preparing to take it back as a panoronavirus virus vaccine.

Dr. of St. Louis University Hoft is working on a universal vaccine that does not depend on antibodies to the spike protein. In collaboration with California-based biotech company Gritstone Oncology, they have created a vaccine that induces cells to make surface proteins that can alert the immune system as if a coronavirus – any coronavirus – were present. They are now preparing a clinical trial to see if it is effective against SARS-CoV-2.

“We are interested in developing a third generation vaccine, which will be on the shelf and ready for future outbreaks,” Dr Machan said.

Dr. Topol believes that scientists should explore another strategy: to discover panoronovirus antibodies made by our own bodies during infection.

Researchers studying HIV and other viruses have Discovered, Among billions of antibodies made during an infection, rare types that work against a vast range of related strains. It may be possible to persuade the body to make it abundant to neutralize these antibodies roughly.

Coronaviruses are similar enough to each other, Drs. Topol said, it’s probably not hard to make vaccines that largely neutralize antibodies. “It’s an easy family of viruses to take down,” he said.

Dr. in search of panoronovirus vaccine. Topol may take longer than sunlight. But even if it takes a few years, it can help prepare the world for the next coronovirus that jumps the species barrier.

“I think we can have vaccines to prevent this kind of epidemic,” Dr. Memoli said. “None of us want to go through this again. And we do not want our children to pass away again, or our grandchildren, or our descendants 100 years from now. “

Source link

Leave a Comment