CNN
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Scientists in Germany say they can develop a nasal vaccine that can shut down a Covid-19 infection in the nose and throat, where the virus first enters the body.
In experiments in hamsters, two doses of the vaccine – which is made with a live but weakened form of the coronavirus that causes Covid-19 – blocked the virus from copying itself in the animals’ upper airways, achieving “sterilizing immunity” and preventing illness, a long-sought goal of the pandemic.
Although this vaccine has many difficulties to be cleared before it can be obtained in the doctor’s office or drug store, other nasal vaccines are in use or are about to finish clinical trials.
China and India are both rolling out vaccines delivered through nasal swabs by the end of the fall, though it’s unclear how they will work. Studies on the effectiveness of these vaccines have not been published, leaving most of the world to wonder if this method to protect people works in humans.
The US has reached something of a Covid-19 steal. Even with the dark days of the pandemic behind us, hundreds of Americans are still dying every day as infection continues in the background as we return to normal life.
As long as the virus continues to spread among humans and animals, there is always the potential for it to adapt to a more infectious or more destructive version of itself. And while covid infections have become manageable for the healthiest people, they can still risk a disaster in vulnerable groups such as the elderly and immunocompromised.
Researchers are hoping for a series of Covid-19 vaccines, which aim to shut down the virus before it has a chance to prevent respiratory infections.
One way scientists are trying to do that is to boost mucosal immunity, improving the immune defenses of the tissues that line the upper airways, where the upper airways line up and begin to determine our cells.
It’s a bit like putting firefighters under the smoke alarm in your house, says study author Emanuel Wyler for Molorholtz Molerin in Berlin.
The immunity produced by the shots works throughout the body, but it lives mainly in the blood. That means it can take longer to post a response.
“Once they’re on site, they can immediately put out the fire, but if they’re like 2 kilometers away, they have to drive there first, and at that time, a third of the house,” Wyler said.
Mucosal vaccines are better at eliciting a different type of initial response than injections. They do a better job of calling IgA antibodies, which have four arms to capture invaders instead of two arms with y-shaped Igg antibodies. Some scientists think that IGAS antibodies may be less picky about their targets than IgG antibodies, making them better equipped to detect new variants.
The Nasal vaccine takes a new approach to an old idea: weaken a virus so it’s no longer a threat and then give it to people so their immune systems can learn to recognize and fight it. The first vaccines used in this method date from the 1870s, against anthrax and rabies. At that time, scientists weakened the agents they used with heat and chemicals.
Researchers have manipulated the genetic material of the virus to make it more difficult for cells to translate. This technique, called Codon Pair Deoptimization, smiles on the virus so that it can be shown to the immune system that does not make the body sick.
“You can imagine reading a text … and every letter is a different font, or every letter is a different size, then the text is much more what we do with Codon Pair Deoptimization,” Wyler said.
In the hamster studies, published Monday in the journal Nature MicrobiologyTwo doses of the live but weakened nasal vaccine produced a stronger immune response than an adenovirus vaccine using standard cells.
Researchers think the live attenuated vaccine may work better because it closely mimics the process of a natural infection.
The nasal vaccine also protects the whole coronavirus for the body, not just the spike proteins like the current Covid-19 vaccines that have made immune weapons against a wider range of targets.
As promising as all this sounds, vaccine experts say be cautious. This vaccine still needs to pass more tests before it is ready for use, but they say the results are encouraging.
“Their work is very good. It’s clearly a competent and thoughtful team that did this work,” that of the breeds before it was done, “that of the breeds before it was done,” that of the breeds before it was done, “that of most of the hikes in the vaccines most of them can be returned to the vaccines at the Mayo Clinic. He was not involved in the new research.
The study began in 2021, before the Omicron Variant, so the vaccine tested in these experiments was carried out with the original weight of the coronavirus. In the experiments, when they infected the animals with Omicron, the live but weakened nasal vaccine was better than the others, but the ability to neutralize the virus was low. Researchers think it needs an update.
It also needs to be testable in humans, and Wyler says they are working on that. The scientists partnered with a Swiss company called Rocketvex to begin the phase of clinical trials.
Other vaccines are further along, but progress has been “slow and stagnant,” Poland said. The groups working on these vaccines are struggling to raise the steep costs of getting a new vaccine to market, and they’re doing it in a situation where the people who think where the people who think the race is winning.
In fact, Poland says, we’re a long way off. All it takes is one more shift at the omicron level in the evolution of the virus, and we can return to square one, without effective tools against the coronavirus.
“That’s crazy. We need to develop a pan-coronavirus vaccine that stimulates mucosal immunity and that’s a long time coming,” he said.
At least four nasal vaccines for Covid-19 have reached late-stage human trials, according to tor The Vaccine Tracker Tracker Tracker Tracker.
Nasal vaccines used in China and India rely on harmless adenoviruses to ferry their instructions to cells, although efficacy data for this have not yet been published.
Two other nasal vaccines have completed human studies.
One, a vaccine that can be made cheaply out of chicken eggs, the same way many flu vaccines are, has been developed by researchers at Mount Sinai in New York City.
Another, like the German vaccine, uses a live but weakened version of the virus. It was developed by a company called Codagenix. The results of the studies, carried out in South America and Africa, may come later this year.
The German team said it was looking forward to Codagenix’s data.
“They may be very important to determine where this test is fundamentally promising or not,” Wyler said.
They have reason to worry. Respiratory infections have proven to be difficult targets for inhaled vaccines.
Flumist, a live but weakened form of the flu virus, works reasonably well in children but does not help adults. The reason is considered that adults have immune memories for the flu, and when the virus is injected into the nose, the vaccine largely enhances what is there.
However, some of the most common vaccines such as the vaccine against measles, mumps and rubella use live viruses, so this is a promising approach.
Another consideration is that live vaccinations are not available to everyone. People with compromised immunity are always warned against using live vaccines because even these weakened viruses can be dangerous for them.
“Even though it amplifies strongly, it’s still a real virus,” Wyler said, so it should be used carefully.