Nasal COVID-19 vaccine prevents disease, transmission in animals: Study
A new single-dose, intranasal COVID-19 vaccine fully protects mice against lethal infection, 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 unlike the currently approved COVID-19 vaccines that require an injection.
Critical need for more effective and easy-to-use vaccines: Professor
"The currently available vaccines against COVID-19 are very successful, but the majority of the world's population is still unvaccinated," said Paul McCray, a professor at the University of Georgia, US. "There is a critical need for more vaccines that are easy to use and effective at stopping disease and transmission," McCray, co-leader of the study, said.
Vaccine requires single dose; can be stored for three months
"If this new COVID-19 vaccine proves to be effective in people, it may help block SARS-CoV-2 transmission and help control the deadly COVID-19 pandemic," the professor further said. The researchers noted that the vaccine only requires a single dose and it may be stored at normal refrigerator temperatures for up to at least three months.
Vaccine uses PIV5 to deliver SARS-CoV-2 spike protein into cells
"Because it is given intranasally, the vaccine may also be easier to administer, especially for those who have a fear of needles," the researchers further said. The experimental vaccine uses a harmless parainfluenza virus 5 (PIV5) to deliver the SARS-CoV-2 spike protein into cells where it prompts an immune response that protects against COVID-19 infection.
PIV5 is related to common cold viruses, infects different mammals
PIV5 is related to common cold viruses and easily infects different mammals, including humans, without causing significant disease. Spike protein helps the virus to enter and infect human cells, and vaccines are directed against it.
Inhaled PIV5 vaccine targets mucosal cells
The team has previously shown that this vaccine platform can completely protect experimental animals from another dangerous coronavirus disease called Middle Eastern Respiratory Syndrome (MERS). The inhaled PIV5 vaccine targets mucosal cells that line the nasal passages and airways, which are the main entry point for most SARS-CoV-2 infections and the site of early virus reproduction.
Virus produced in mucosal cells can cause more severe disease
Viruses produced in these cells can invade deeper into the lungs and other organs, which can lead to more severe disease, according to researchers. Viruses made in these cells can be easily shed through exhalation allowing transmission from one infected person to others.
