Even as vaccine manufacturers race to update the first-generation shots in the hopes of patching up our protection for the fall, other scientists are taking a different approach, making vaccines delivered via nasal sprays or tablets that would deploy more immune defenders to the body’s front lines: the lining of the mouth, nose and throat.
“The hope is to shore up the defenses right there in the nose so that the virus can’t even replicate in the nose,” said Dr. Ellen Foxman, an immunobiologist at the Yale School of Medicine. “And then someone who has a really effective mucosal vaccination can’t even really support viral replication or make viruses that can infect other people.
“That would be like the holy grail,” said Foxman, who helped plan the International Congress of Mucosal Immunology meeting this week in Seattle, which is sponsored by pharmaceutical companies Pfizer, Janssen and Merck.
If it works, there’s hope that mucosal immunity could slow the development of new coronavirus variants and finally bring the Covid-19 pandemic under control.
There’s a long way to go before that happens, however, and many scientists say the approach needs an injection of funding to accelerate the pace of development, much in the same way the billions of dollars doled out by Operation Warp Speed delivered the first generation of Covid-19 vaccines in record time.
More than a dozen nasal spray vaccines against Covid-19 are being tested around the world. Many use new kinds of technologies, like delivering instructions for making the spike protein of the coronavirus through harmless Trojan horse viruses. Others aim to deploy the mRNA technology that was so successful in the injectable vaccines in the form of a nasal spray.
One company, Vaxart, has even made a tablet that delivers instructions for making parts of the new coronavirus to the gut, which then builds immunity in “the tube.” The Vaxart tablet, which is about the size and shape of an aspirin, uses an adenovirus – the same delivery system utilized by the Johnson & Johnson and AstraZeneca Covid vaccines – to ferry instructions for making parts of the SARS-CoV-2 spike protein into cells in the gut, which stimulates the release of antibodies in the nose and mouth.
In an early trial that included 35 participants, 46% had an increase of antibodies in their nose after taking the tablet vaccine. Those who did seemed to create a broad spectrum of immunity to a number of types of coronaviruses, and they appeared to hold on to that protection for about a year. That may be a bit longer than injectable vaccines, though more research is needed to confirm those results.
Source: CNN Read the full article here https://www.cnn.com/2022/07/18/health/mucosal-immunity-covid-19/index.html