Could a nasal COVID-19 vaccine offer different advantages than a subcutaneous injection?

The National Institutes of Health's National Institute of Allergy and Infectious Diseases (NIAID) Institute of Infectious Diseases has announced that it will begin Phase 1 trials of the investigational COVID-19 vaccine MPV/S-2P., Earlier this summer.¹ The vaccine uses a live-attenuated version of a virus called mouse pneumonia virus (MPV), which does not cause disease in humans. Its mechanism of action is to deliver a version of the SARS-CoV-2 spike protein (S-2P) stabilized in its pre-fusion conformation. The researchers explain that this vaccine delivery shows an affinity for epithelial cells lining the respiratory tract, which could be effective in delivering the vaccine to the site where natural coronavirus infection begins.¹

The researchers are pursuing their work following successful preclinical trials, in which the vaccine was deemed safe and well tolerated in primate studies.¹

This is NIAID's first clinical trial conducted as part of the Department of Health and Human Services' (HHS) Project NextGen. Led by the Biomedical Advanced Research and Development Authority, part of the HHS Strategic Preparedness and Response Office, and NIAID, Project NextGen is a federal government and private sector partnership to expand the pipeline of innovative new vaccines and therapeutics. Through Project NextGen, NIAID will advance the clinical development of promising next-generation COVID-19 vaccines in Phase 1 and 2 trials.¹

Study parameters

For the study, researchers aim to enroll 60 adults between the ages of 18 and 64 who have received at least three doses of an FDA-approved or authorized mRNA COVID-19 vaccine. Study volunteers will be divided into three cohorts: participants in the first cohort will receive a single dose of the investigational vaccine administered via nasal spray at the lowest dose, while participants in the next two cohorts will receive gradually increasing doses. Over seven follow-up visits over roughly a year, scientists will measure how well the vaccine candidate is tolerated and whether it produces an immune response in the blood and nose.¹

Trial sites include Baylor College of Medicine, Emory University Hope Clinic and New York University.¹

Potential benefits

As COVID-19 variants continue to evolve, with existing vaccines, the goal and expectations of vaccination have shifted from preventing disease to minimizing the severity of the disease, including hospitalization and mortality.

MPV/S-2P vaccine It generated a strong systemic immune response, including antibodies against SARS-CoV-2, and local immunity in cells of the nasal and respiratory mucosal tissues. Human and animal studies suggest that mucosal immunity is more effective than systemic immunity in controlling respiratory viral replication.¹

“While first-generation COVID-19 vaccines remain effective at preventing severe illness, hospitalization, and death, they are less effective at preventing infection and mild illness,” said NIAID Director Jeanne M. Marrazzo, M.D., M.P.H. “With new viral variants continually emerging, it is critical that we develop next-generation COVID-19 vaccines, including intranasal vaccines, that can reduce infection and transmission of SARS-CoV-2.”¹

And for people who are reluctant to get vaccinated due to fear of needles, this could be an alternative way to get vaccinated that doesn't require rolling up your sleeve and receiving a subcutaneous injection.

Are past nasal influenza vaccine recommendations a guide?

Ultimately, the future of an intranasal COVID-19 vaccine may become a reality if proven safe and effective. One only needs to look to the experience of intranasal influenza vaccines to get a glimpse of a similar prospect for a COVID-19 vaccine.

Another group that may benefit from an intranasal COVID-19 vaccine could be the pediatric population, who may be in the midst of receiving childhood vaccinations, so an intranasal vaccine could spare them the need for another round of vaccinations.

Although the intranasal influenza vaccine has been studied extensively in this population, recommendations vary, with federal agencies and medical specialty societies having different positions depending on the individual year.

for example, In 2016In 2016, the Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP) voted against the use of live attenuated influenza vaccines (LAIVs), also known as “nasal sprays,” for the 2016-2017 influenza season.² vice versa, 2019-2020 Seasonal Respiratory Disease SeasonThe American Academy of Pediatrics has recommended a nasal spray form of the flu vaccine.³

References

1. NIH-sponsored COVID-19 nasal vaccine trial begins. NIH. July 1, 2024. Accessed August 8, 2024.
https://www.nih.gov/news-events/news-releases/nih-owned-trial-nasal-covid-19-vaccine-opens
2. Anwar S. The CDC recommends against using the nasal spray influenza vaccine for the 2016-2017 influenza season. Contagion. June 23, 2016. Accessed August 8, 2024.
https://www.contagionlive.com/view/cdc-advises-against-use-of-nasal-spray-flu-vaccine-for-the-20162017-flu-season
3. Kaltwasser J. Influenza vaccination, nasal spray, recommended for children as well for the 2019-2020 season. Contagion. April 2, 2019. Accessed August 8, 2024.
https://www.contagionlive.com/view/flu-shot-nasal-spray-recommended-equally-by-aap-for-20192010-season