The nasal vaccine against SARS-CoV-2 Generally minimizes mortality. But they are less effective. Enhancing immunity in the respiratory tract via mucosal vaccination may protect against infection and reduce viral spread.
The Centenary Institute and the University of Sydney have developed a new nasal vaccination strategy. This strategy helps produce influential lung immunity and protection against the SARS-CoV-2 coronavirus.
The new vaccine strategy has been tested successfully on the mice models. They delivered the vaccine nasally, making its way through the respiratory tract, adhering to the tissues of the nasal cavity, airways, and lungs.
The vaccine generated high levels of protective antibodies in the airways. It also increased T-cell responses in the lungs. Significantly, none of the vaccinated mice became infected with COVID-19.
The results show that the approach could potentially embellish Immuno-protection against COVID-19 infection and reduce ongoing viral spread.
The new vaccine comprises the SARS-CoV-2 spike protein and an adjuvant called Pam2Cys. Pam2Cys is a molecule that helps stimulate a stronger immune response in the body. It was developed by Professor Richard Payne, NHMRC Investigator in the University of Sydney’s Faculty of Science.
Lead author of the study, Dr. Anneliese Ashhurst, research fellow in the University of Sydney’s Faculty of Medicine and Health and the Centenary Institute, said that while current COVID-19 vaccines are critical, there were some limitations, including the waning of immunity post-vaccination and infection, combined with the impact of new viral variants evolving.
Dr. Ashhurst said, “Current vaccines against SARS-CoV-2 substantially reduce mortality and severe disease, but protection against infection is less effective. Vaccinated individuals are still catching COVID-19 and can spread the infection, so breakthrough infections are still occurring,”
“To stop the viral spread and to prevent this virus from mutating, we need a new vaccine approach that blocks COVID-19 transmission,” she said.
“Our vaccine differs from most current COVID-19 vaccines in that it enables the generation of an immune response directly in those areas of the body that are likely to be the first point of contact for the virus – the nose, airway, and lungs. This may help explain the vaccine’s effectiveness,” said Dr. Ashhurst.
He added that adapted versions of the new nasal vaccine could also be potentially applied to other viral or bacterial respiratory diseases such as influenza, avian flu, SARS, and MERS.
- Ashhurst, A.S., Johansen, M.D., Maxwell, J.W.C. et al. Mucosal TLR2-activating protein-based vaccination induces potent pulmonary immunity and protection against SARS-CoV-2 in mice. Nat Commun 13, 6972 (2022). DOI: 10.1038/s41467-022-34297-3