Unlike other coronavirus vaccines, the scientists have developed a nasal vaccine that targets the contagious Coronavirus infection, and a one dose can be given through the nose and has been found to be effective in preventing the infection in mice vulnerable to the virus.
The researchers founded that the nasal delivery route has created a strong immune response throughout the body, but it was mostly effective in the nose and respiratory tract, preventing the infection from taking hold in the body.
The next plan of research team is to test the vaccine in non-human primates and humans to see if it is safe and effective in preventing coronavirus infection, according to the study published in the Journal Cell.
“We were happily surprised to see a strong immune response in the cells of the inner lining of the nose and upper airway — and profound protection from infection with this virus,” said Michael S Diamond, the study senior author from the Washington University.
“These mice were well protected from disease. And in some of the mice, we saw evidence of sterilizing immunity, where there is no sign of infection whatsoever after the mouse is challenged with the virus,” he added.
To develop the vaccine, the researchers inserted the virus’ spike protein, which coronavirus infection uses to invade cells, inside another virus, which is called an adenovirus,that causes the common cold.
But the scientists tweaked the adenovirus, rendering it unable to cause illness.
The harmless adenovirus carries the spike protein into the nose, enabling the body to increase an immune defense against the SARS-CoV-2 virus without even becoming sick.
In a different innovation beyond nasal delivery, the new vaccine incorporates two mutations into the spike protein that stabilize it in a specific shape, that is most favorable to forming antibodies against it.
The researchers has compared this vaccine administered to the mice in two different ways such as through nose and intramuscular injection.
Although the injection induced an immune response that prevents pneumonia but it did not prevent the infection in the nose and lungs.
Such a vaccine may reduce the severity of coronavirus, but it would not totally block the infection or prevent virus infected individuals from spreading.
In contrast, the nasal vaccines delivery route prevented the infection in both the upper and lower respiratory zone the nose and lungs, showing that vaccinated individuals would not spread the virus or develops infections elsewhere in the body.
The study is promising but cautioned that the vaccine to date has only been studied in mice, said the researchers.
“In these mouse models, the vaccine is highly protective and we’re looking forward to beginning the next round of studies,” wrote the study authors.