In the early days of the pandemic, the federal government launched Operation Warp Speed, the public-private initiative that was partly aimed at accelerating vaccine development.
It turned out to be a success and brought the first Covid vaccines to the market in about 9 monthsan unheard of time frame for a process that normally takes years or even decades.
But that same effort has not been made to develop the next generation of vaccines, which experts say will provide even more protection.
Nasal vaccines in particular can show promise; many scientists consider such an approach to have the potential to completely prevent infection.
That’s because nasal vaccines give a boost of immunity right where the virus enters the body.
These vaccines “concentrate immune protection in the upper respiratory tract,” Dr. Anthony Fauci, the White House chief medical adviser, told NBC News in an interview. In doing so, the “antibodies that are trying to protect you from the virus entering your body are on the front line to protect you.”
The lack of initiative has disappointed some scientists who say vaccines administered through the nose or upper respiratory tract may be better suited to prevent infections caused by the coronavirus compared to intramuscular injections.
“There’s not much incentive to invest in these things anymore because Operation Warp Speed is over and a lot of people think this is all over and we don’t need better vaccines,” said Florian Krammer, an immunologist at the Icahn . School of Medicine at Mount Sinai in New York City. He is support an effort on Mount Sinai to develop a nasal vaccine.
But as the pandemic continues, it is clear that existing vaccines offer little protection against infection, particularly against omicron and its family of immune-evasive subvariants. Pfizer-BioNTech and Moderna injections and boosters remain resistant to hospitalization and death, but completely blocking infection can even mild illnesses. It can also slow down the transmission of the virus and prevent other serious problems, such as long-term Covid.
“A traditional shot in the arm, you get what’s called systemic immunity, which is the buildup of antibodies that are essentially distributed in different organs of the body,” Fauci said. That’s why, he said, those vaccines do very well in protecting against serious disease.
Nasal vaccines are also designed to induce the production of antibodies, but in the mucosal tissue – the inner lining of the nose, throat and mouth, where the virus usually enters the body.
To effectively protect against infection, “you need mucosal immune responses,” says Michal Tal, an immunologist at Stanford University.
Nasal Vaccines in the US
A nasal vaccine is still a long way off in the United States, though that’s not due to a lack of trying: Numerous nasal vaccines for Covid are in development in the country, Fauci said, but the vast majority are still in the pipeline. preclinical stage or early in human clinical trials. The National Institute of Allergy and Infectious Diseases, which Fauci leads, funds some early research about nasal vaccines.
Akiko Iwasaki, an immunologist at Yale University, is among the group of researchers working on a nasal vaccine.
Her team is looking at two approaches: a protein-based nasal spray and an mRNA vaccine delivered into the nose using nanoparticles.
In either case, the nasal vaccine is intended to be used as a booster dose, building on the existing immunity created by previous vaccinations, Iwasaki said.
The strategy is called “prime and spike,” she said. “Prime is any kind of mRNA vaccine that has already been approved for Covid. And spike is the nasal booster.”
She and her colleagues have seen promising results in preclinical studies so far, post data to a preprint server that found this year that the nasal vaccine administered as a booster dose elicited a strong immune response in the airways of mice.
Krammer, of Mount Sinai, is working on a nasal vaccine that is currently in Phase 1 trial in the US and a little further in Mexico.
If the US trial is successful, they hope to begin Phase 2 sometime next year, he said.
This vaccine uses a modified version of a virus that usually infects birds to target the coronavirus spike protein, he said. The vaccine was found to elicit an immune response in mice.
In other countries, the research is further: Phase 3 studies are underway in India and China, for example.
A long way to go
Fauci warned that nasal vaccines in the US are still “a few years” away. Unlike Operation Warp Speed, which has benefited from generous funding from the government, Congress has provided little for additional vaccine research, he said.
While the early findings are promising, there’s no guarantee that any of the vaccines will be successful, he said.
Only one nasal vaccine is approved for use in the US: FluMist, a flu vaccine. But FluMist, while an attractive option for children who are afraid of needles, is less effective than the traditional injections.
If the research pans out, Fauci said he’s hopeful that a nasal vaccine will be available in “a few years.” There is also no guarantee that any of the vaccines will be successful, he added.
But “any product that looks promising, I can assure you, the FDA would be very happy to look into it,” he said.
According to Yale immunologist Iwasaki, even a successful nasal vaccine is unlikely to be the last shot a person needs against Covid.
The nasal vaccine “will likely need to be repeated, like all boosters, not just because of waning immunity, but possibly because of potential concern variants” that can evade immunity, she said.