In the early days of the pandemic, the federal government launched Operation Warp Speed, a public-private initiative aimed in part at speeding vaccine development.
It proved successful, bringing the first Covid vaccines to market in about 9 months, an unheard of time frame for a process that normally takes years or even decades.
But the same efforts have not been made to develop the next generation of vaccines, which experts believe will provide even greater protection.
Nasal vaccines, in particular, may hold much promise; many scientists believe that such an approach has the potential to prevent infections altogether.
This is because nasal vaccines provide a boost of immunity right where the virus enters the body.
These vaccines “concentrate immune defenses in the upper respiratory tract,” said Dr. Anthony Fauci, the White House’s chief medical adviser, in an interview with NBC News. That way, “the antibodies that are trying to protect you from the virus entering your body are right there on the front line protecting you.”
The lack of initiative is a disappointment to some scientists, who say vaccines given through the nose or upper respiratory tract may be better suited to prevent infections caused by the coronavirus than injections given intramuscularly.
“There’s not a lot of appetite to invest in these things anymore because Operation Warp Speed is over and a lot of people think it’s all done and we don’t need better vaccines,” said Florian Kramer, an immunologist at the Icahn School of Medicine at Mt. Sinai in New York. He supports efforts at Mount Sinai to develop a nasal vaccine.
But as the pandemic continues, it’s clear that existing vaccines don’t do much to protect against infection, especially from omicron and its family of immune-evading subvariants. Shots and boosters from Pfizer-BioNTech and Moderna continue to hold out against hospitalization and death, but blocking infection completely can prevent even mild illness. It can also limit transmission of the virus and prevent other serious problems such as prolonged Covid.
“A traditional shot in the arm, you get what’s called systemic immunity, which is a build-up of antibodies that essentially distribute to different organs of the body,” Fauci said. That’s why, he said, these vaccines do so well against protecting against severe disease.
Doctor holding spray bottle for nasal vaccine for COVID-19. (Getty Images)
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 normally enters the body.
To effectively defend against infection, “you need a mucosal immune response,” said Michal Tal, an immunologist at Stanford University.
Nasal vaccines in the US
A nasal vaccine still remains a long way off in the United States, though it’s not for lack of trying: There are numerous nasal Covid vaccines in development in the country, Fauci said, but the vast majority are still in preclinical or early stages of clinical trials. on people. The National Institute of Allergy and Infectious Diseases, which Fauci directs, funded some early research into nasal vaccines.
Akiko Iwazaki, 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 to the nose using nanoparticles.
In both cases, the nasal vaccine is intended to be used as a booster dose, building on existing immunity built up through previous vaccinations, Iwazaki said.
The strategy is called “first and jump,” she said. “Prime is any type of mRNA vaccine that is already approved for Covid. And spike is the nasal booster.”
She and her colleagues have so far seen promising results in preclinical studies, publishing data on a preprint server this year that found the nasal vaccine, given as a booster dose, generated a strong immune response in the airways of mice.
Mount Sinai’s Kramer is working on a nasal vaccine that is currently in phase 1 trials in the US and further down the line in Mexico.
If the U.S. trial is successful, they hope to begin Phase 2 sometime next year, he said.
This vaccine uses a modified version of a virus that normally infects birds to target the spike protein of the coronavirus, he said. The vaccine was found to generate an immune response in mice.
Research is moving forward in other countries: in India and China, for example, phase 3 trials are underway.
Long way
Fauci cautioned that nasal vaccines in the US are still “several years away.” Unlike Operation Warp Speed, which benefits from generous government funding, Congress has provided little for additional vaccine research, he said.
While the early findings are promising, there is no guarantee that any of the vaccines will ultimately 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 traditional shots.
If the research is successful, Fauci said he hopes a nasal vaccine will be available in “a few years.” Also, there is no guarantee that any of the vaccines will be successful, he added.
But “any product that looks promising, I can assure you, the FDA will be very eager to look at it,” he said.
According to Iwazaki, the Yale immunologist, even a successful nasal vaccine is unlikely to be the last vaccination a person needs against Covid.
The nasal vaccine “will probably need to be repeated, like all other boosters, not only because of waning immunity, but potentially because of variants of the concern that can arise” that can evade immunity, she said.
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