Cutting highlights last year’s thorough scientific pursuit, and beyond. And it highlights a more pressing and comprehensive challenge. Is chasing the latest variants a viable strategy? What if a single vaccine could block all repetitions of this coronavirus and the next coronavirus instead of testing and deploying new shots when new variants emerge?
Rebooting vaccines to match new variants is now becoming part of scientific muscle memory.Pharmaceutical companies made vaccines to fight beta, delta And now Omicron..None of those shots Still needed, but for many scientists, it’s a short-term, short-sighted, unsustainable strategy.
David R, a viral immunoscientist at the University of North Carolina at Chapel Hill. Martinez said: “This can last forever.”
The original shot has held up very well, but there is no guarantee how it will work for the next variant. Scientists like Martinez want to end the catch-up cycle.
They have invented vaccines designed to promote widespread protection. This is an immune barrier that repels not only the SARS-CoV-2 variants we know, but also those that have not yet emerged.
At the very least, the world needs a truly mutation-resistant vaccine. Even better are shots that stop future pandemics and protect them from the unknown coronavirus that jumps from animals to humans in the coming years.
Some experts are wondering why Operation Warp Speed for these universal vaccines is not yet available.
President Biden’s chief medical adviser, Anthony S. Forch, emphasizes the need for patience as well as urgency.There are scientific gaps that need to be filled to build a widely protected and long-lasting vaccine — and National Institute of Health Last fall, we awarded $ 36 million to a group trying to answer basic questions.
“Don’t confuse the speed and ease of developing a coronavirus vaccine for SARS-CoV-2 with the extraordinary obstacles you may face when trying to obtain a protective vaccine,” Fauci said. Said in an interview with. The Washington Post. “There are many scientific discoveries that need to be addressed.”
But personally, scientists say Fauci is urging them to hurry.
“I’m worried about tracking variants because there are always new variants,” he said. Drew Weissman, University of Pennsylvania Perelman Medical College Vaccine Pioneer and Immunologist, working on the Pancorona virus vaccine. “Currently it pops up every 6 months, but it will pop up until the world is vaccinated.”
As with the success of the first vaccine, many scientists working on next-generation shots had big ideas in 2021. Perhaps we could make a vaccine that fights off two coronaviruses, as well as SARS-CoV-2 and the original SARS.Cause coldMiddle East Respiratory Syndrome, and future bat coronaviruses that may jump into humans.
A New England Journal of Medicine Last year’s study showed that, at least conceptually, it is possible to create a wide range of immune defenses against many viruses. Chinese researchers show that survivors of the first SARS outbreak who were vaccinated with SARS-CoV-2 20 years ago produced antibodies that could block a range of variants and other coronaviruses. I did.
However, it is tricky to make a single vaccine that works against such a wide range of viruses, and beta, delta, and omicron variants have readjusted some of their radical ambitions.
“When SARS-CoV-2 first appeared, it was a virus with few tricks, so we were very successful,” said Scripps Research Institute’s Chairman of the Department of Immunology and Microbiology. Dennis Burton said. “But basically, we’re getting more and more tricks, so it’s getting harder and harder to deal with. We need to be more accurate about the antibodies that we induce through the vaccine.”
Before developing a vaccine to stop the next pandemic, it becomes clear that a more conservative goal, an antimutation vaccine against SARS-CoV-2, may be needed to end this crisis. I did.
“Omicron really pointed out to us,” Hey, we haven’t got out of this epidemic yet, and we don’t know what the future holds for this epidemic. ” Barton Haynes, an immunological and vaccine expert at Duke University School of Medicine, needs to focus on the next possible outbreak, but all variants that can occur within the next 3-5 years. You also need to make sure you cover it. medicine.
In the short term, Haynes’ team is focused on blocking variants.They are manufacturing vaccination — Nanoparticles with spike fragments scattered on the surface. In animal studies, the vaccine provided extensive immune defenses against variants, the original SARS virus and the bat coronavirus. Haynes wants people to start testing it this year.
Results are expected soon First human test another”Bread SARSA vaccine developed by scientists at the Walter Reed Army Institute. Early studies have also shown that they also offer broader protection than first-generation shots. It consists of multifaceted nanoparticles interspersed with spikes found in the original version of the coronavirus that emerged in Wuhan, China.
Vaccines teach the immune system to recognize the virus. They often do this by presenting a version of the virus. This can be a trivial feature, such as spikes on the outside of the coronavirus. The power of these new vaccines comes from what features they exhibit and how they present them. Fragments of the virus are assembled on multifaceted nanoparticles, similar to what spikes look like on the surface of the virus itself. This is an approach that helps focus on the immune response.
“The immune system has evolved to react strongly to repetition. The virus has repetitive sequences of proteins on its surface,” said Neil King, a biochemist at Washington University, with another variant proof. I’m waiting. Vaccine candidate In human clinical trials. “That’s why nanoparticle vaccines work more effectively because they present the antigen as a repetitive sequence and elicit its strong response.”
“Worth to try”
The first version of the coronavirus vaccine was powerful, but simple.They take pointed proteins from the outside of the virus that emerged in 2019 and adjust them Correctly shaped spikes — And presented those spikes to the immune system.
Next-generation vaccines designed to stop future pandemics will probably need more sophistication.
Martinez is working on vaccines at UNC, which shows the immune system “Chimera” spikes.. Like chimeric creatures in Greek mythology — the lion’s head, the central part of the goat, the trailing edge of the snake — these vaccines use patched spikes from various coronavirus fragments. Part of SARS-CoV-2, another bit of the original SARS virus, and the third component of the bat coronavirus.
Other researchers like King are building “mosaic” vaccines and cocktail vaccines that include other combinations. For example, important parts of the peplomers from SARS-CoV-2, SARS, and the two bat coronaviruses may be interspersed in small particles.Created by researchers at the California Institute of Technology Mosaic nanoparticles There are 4-8 coronavirus fragments.
The exact approach to forming the best universal vaccine remains a matter of scientific debate. But this is certain. Renewing the vaccine every 6 months is not a rational or impartial way to protect people around the world.
“I don’t think the experience of the variants so far is trying to pursue the emergence of new variants and the rapid production of vaccines specific to the variants. This is long-term, even at high incomes. I don’t think it’s a strategic strategy. It’s not a nation, and certainly a resource-poor environment, “said Richard Hut, Chief Executive Officer of the Infectious Disease Control Innovation Coalition, a non-profit funding effort for development. Chet said. Variant proof When Universal vaccination.
It is important to discover that there are antibodies that can recognize and neutralize various viruses. However, learning how to trigger them to create protective shields can be more complicated than you might think.
It may not be enough for people to produce antibodies that block various coronaviruses. The secret is whether the vaccine can produce enough to protect people. For example, in HIV, antibodies that block many strains of the constantly mutating virus have been isolated from long-term infected individuals. However, recreating what nature can accomplish with vaccines is approaching as the Holy Grail of the field.
In SARS-CoV-2, peplomers look like trees, and rare antibodies that bind to the roots of trees can block various associated coronaviruses. In laboratory researchSaid Duane R. Wesman, an immunoscientist at Brigham and Women’s Hospital in Boston.
“But it’s very infrequent, and if you’re making a vaccine that just does it, you need to make sure that it may not be that easy,” Wesemann said. “It is not clear if these special antibodies can be elicited at sufficiently high levels.”
The universal flu vaccine arrives in a more complex world than the first-generation vaccines encountered. People have different levels of pre-existing immunity from vaccinations and mutant-related infections.
Scientists say how previous exposures, known as immune imprinting, or sometimes called “antigenetic sin,” affect people’s response to new vaccines, good or bad. I do not agree with One possibility is that the new vaccine will produce the strongest response to the virus that people are first exposed to, rather than the latest. However, vaccine designers like Martinez believe that this habit of the immune system could be used as an asset to focus the response on the right target.
Another scientific issue that has not yet been resolved is durability. A wide range of vaccines with rapidly declining defenses may not be practical to use to prevent future pandemics. After all, SARS appeared about 20 years ago, and MERS appeared 10 years later.
“I’m looking for a tetanus-like shot,” Haynes said. “We all need to be vaccinated against tetanus every 10 years. That’s really great.”
The quest for a truly universal vaccine is urgent, but many experts warn that it is a very different challenge than creating a first-generation vaccine.
“We’ve been researching the flu virus for over 70 years, and we’re trying to make a universal flu vaccine, but we haven’t done it yet,” says Yoshihiro Kawaoka, who works on the Pancorona virus vaccine. I did. University of Wisconsin-Madison. “But this is another virus and I think it’s worth trying. What I’m trying to say is that it may not be easy.”