A new single-dose COVID-19 intranasal vaccine fully protects mice against deadly infections and also blocks transmission of the SARS-CoV-2 virus in ferrets, a study has shown.
The new vaccine, described in the journal Science Advances, is administered through a nasal spray similar to those commonly used to vaccinate against influenza.
This new method is different from currently approved COVID-19 vaccines that require injection.
“The currently available COVID-19 vaccines are very effective, but the majority of the world’s population is still unvaccinated and there is a critical need for more easy-to-use and effective vaccines to stop disease and transmission.” said Paul McCray, professor at the University of Georgia, United States.
“If this new COVID-19 vaccine proves effective in humans, it may help block the transmission of SARS-CoV-2 and control the COVID-19 pandemic,” said McCray, co-head of the ‘study.
The researchers noted that the vaccine only requires a single dose and can be stored at normal refrigerator temperature for at least three months.
Because it’s given intranasally, the vaccine may also be easier to administer, especially for those afraid of needles, they said.
“Our preclinical data shows that this vaccine not only protects against infection, but also dramatically reduces the chance of transmission,” said Biao He, professor at the University of Georgia and co-lead of the study.
The investigational vaccine uses a harmless parainfluenza 5 (PIV5) virus to deliver the SARS-CoV-2 spike protein into cells where it triggers an immune response that protects against COVID-19 infection.
PIV5 is related to cold viruses and easily infects various mammals, including humans, without causing significant disease.
The spike protein helps the virus enter and infect human cells, and vaccines are directed against it.
The team has already shown that this vaccine platform can completely protect laboratory animals from another dangerous coronavirus disease called Middle East Respiratory Syndrome (MERS).
The inhaled PIV5 vaccine targets the mucous cells that line the nasal passages and respiratory tract, which are the primary entry point for most SARS-CoV-2 infections and the site of early reproduction of the virus.
Viruses produced in these cells can invade the lungs and other organs of the body deeper, which can lead to more serious disease, the researchers say.
Viruses made in these cells can be easily excreted through exhalation, allowing transmission from one infected person to others, they said.
The study showed that the vaccine produced a localized immune response, involving antibodies and cellular immunity, which completely protected mice from lethal doses of SARS-CoV-2.
The vaccine also prevented infection and disease in ferrets and appeared to block transmission of COVID-19 from infected ferrets to their unprotected and uninfected cage mates, the researchers added.
(This story was not edited by Devdiscourse staff and is auto-generated from a syndicated feed.)