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- Scientists are developing all-in-one vaccines to protect against several coronaviruses.
- These shots could be used as COVID-19 boosters and could prevent future virus pandemics, they say.
- More than 20 groups are working on the plans, which require significant funding and regulatory approval.
This pandemic is unlikely to be the last.
Experts warned in March of a “serious threat” from coronaviruses of the same family as SARS-CoV-2, the virus that caused the COVID-19 pandemic.
Ralph Baric, an epidemiologist at the University of North Carolina School of Medicine, told New Scientist in March that it was “very easy to imagine” the emergence of a new coronavirus almost as infectious as SARS -CoV-2 but much more lethal.
As of Friday, Johns Hopkins University had recorded an estimated 234 million COVID-19 infections and 4.8 million deaths, for a death rate of around 2%. The true lethality of the virus is generally believed to be less than this, as mild cases are more likely to go unrecorded than deaths. Either way, other coronaviruses that have appeared in recent years, although less infectious than the last one, have been much more deadly.
The virus that causes MERS has killed about a third of people known to have caught it, while the SARS virus, which is technically known as SARS-CoV-1, has killed about 10% of people known to have it. be infected.
In light of this, Dr Anthony Fauci, chief medical adviser to President Joe Biden, said at a public event in February that it would be “shame on us” if we did not develop a “universal vaccine against coronavirus “.
Scientists are trying to do just that.
Baric was one of the first scientists to study the antibodies of people with COVID-19 for protection against other coronaviruses. His hope is to develop an all-in-one coronavirus vaccine that protects against many members of the SARS-CoV family.
He is not alone. John Lewis, CEO of Canadian biotech company Entos, told Insider the company hopes to develop a single vaccine that protects against all coronaviruses by the end of the year.
But Entos, and more than 20 other groups around the world in the race to develop all-in-one vaccines, face a difficult road. Entos acknowledged that it needed a partnership with a pharmaceutical company to finance and manufacture the vaccine. It must also convince regulators of its approach, which is far from guaranteed.
The science of targeting many coronaviruses at once is already difficult – and turning that research into a working vaccine will involve experimentation with expensive human trials. Dr Dennis Burton, chairman of the immunology and microbiology department at Scripps Research, said the introduction of vaccines to humans was “a bit of a black box.”
“We can make some predictions, but the way people respond to vaccines is complex,” he told Insider. “We are all very different and it has to work globally.”
Even if a large coronavirus vaccine works, it might not be able to prevent local outbreaks of the virus, Burton said. “But at least if you have something that can react quickly and contain it in an area before it gets out of hand and becomes a pandemic,” he added.
How vaccines can target many coronaviruses
The coronavirus family shares similar characteristics. The goal of so-called largely protective coronavirus vaccines is to make the body react to parts of the viruses that are common to the whole family. They are called conserved sites. They are usually essential for the virus to function and therefore are less likely to mutate.
In theory, if you are vaccinated with a largely protective vaccine, your body will fight off any future coronaviruses that have not yet passed from animals to humans, as long as they have the site kept in common. These vaccines promise better protection than the “variant-proof” vaccines, also in development, which are specifically intended to fight multiple variants of SARS-CoV-2 at one time.
New evidence suggests that antibodies from one coronavirus protect against another, suggesting that all-in-one coronavirus booster shots may work.
A study published in the New England Journal of Medicine on August 18 from Duke-NUS Medical School in Singapore found that people who contracted SARS in 2003 and then later received Pfizer-BioNTech’s COVID-19 vaccine produced antibodies that protected against all of the known variants that cause COVID-19, as well as other coronaviruses carried by animals.
Wang Linfa, the author of the study, said in a statement at the time that the findings could aid in the development of “next-generation vaccines” that “not only help us control the current COVID-19 pandemic, but can also prevent or reduce the risk of future pandemics caused by related viruses. “
Dr Eric Topol, Director of the Scripps Research Translational Institute, said on twitter when the study was published, “we continue to move closer to the discovery of antibodies” that protect the “beta” subtype of coronavirus, which includes the SARS virus, MERS virus and SARS-CoV-2 .
“I don’t understand why we are running away with variant-specific vaccines when that might be our number one priority,” he said.
The broadest possible immune response
To repel more than one coronavirus, the conserved site must trigger the body’s immune response. This gives vaccine developers two avenues of protection.
First, the antibody response, which prevents a virus from entering cells, and second, the T-cell response, which identifies and destroys all infected cells. The location of a conserved site usually dictates the type of immune response.
We don’t yet know which approach is best for all-in-one coronavirus vaccines, but companies like Entos and U.S. immunotherapy company Gritstone are using machine learning to find virus sites that trigger responses of T lymphocytes.
Lewis of Entos said a conserved site was 95% similar for all variants of SARS-CoV-2 causing the ongoing pandemic. If a vaccine generated a strong T cell response against that part of the virus, he said, “you would effectively gain control of all the variants currently in circulation, and then potentially more widely against other coronaviruses.”
Lewis added that it would be “a big hurdle” to convincing regulators of T-cell inducing vaccines. His reasoning is that the antibody response would likely be much lower than for COVID-19 vaccines from Pfizer-BioNTech and Moderna – and regulators have focused on antibody levels in the past.
But he remains optimistic. “If we get a pharmaceutical partnership and convince the regulator of our approach, we could get a largely protective coronavirus vaccine by the end of the year,” he said.
Gritstone is trying to find both conserved sites that trigger antibodies and fragments of the virus that can be recognized by T cells. “The virus has a finite number of ways to escape our immune system,” Insider Andrew Allen, CEO of Gritstone, “and the more lanes we can block, the better.”
Allen said Gritstone plans to develop a vaccine that protects against multiple coronaviruses, but a true pan-coronavirus vaccine may be out of reach due to variations between viruses in the family.
This is because coronaviruses, despite the similarities, can vary a lot from each other.
Karin Jooss, chief scientist at Gritstone, told Insider that the MERS and SARS viruses differ by about 60% and the company has yet to find a common region it could target with a vaccine.
Antibodies are “critical”
Burton said T cells were probably important in fighting coronaviruses, but described the antibodies as “critical.”
Scientists at the Duke Human Vaccine Institute are focusing on a vaccine that generates antibodies against the beta coronavirus subgroup.
They found that parts of viruses that attach to human cells are preserved through beta-coronaviruses. These common sites trigger an antibody response.
A May lab study found that Duke vaccine technology prevented many coronaviruses from entering cells.
This type of research is promising, but, as John Moore, professor of microbiology and immunology at Weill Cornell Medical College, told Insider, it is “early stage.”
The biggest hurdle will be getting it out of the lab and into humans, which involves expensive testing and expensive materials, he said.
Kevin Saunders, assistant professor in Duke’s immunology department, who heads the Duke team, said he needed $ 20 million to get the project out of the lab and into an early-stage human study of 50 people .
That’s a high hurdle, no doubt – but the rewards would be just as high for getting it right. “We hope,” said Entos’ Lewis, “this will be the last booster you will ever need.”
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