A recent study conducted by researchers from the University of Iowa and the University of Georgia has heightened the prospects of a single-dose, intranasal COVID-19 vaccine which can be highly effective against the coronavirus.
The findings, which were recently published in the journal Science Advances, revealed that mice that were administrated the dose not only remained fully protected against COVID-19 but also didn’t transmit the virus among them.
Underlining the significance of the breakthrough vaccine, Dr. Paul McCray, MD, Professor of Pediatrics-Pulmonary Medicine, and Microbiology and Immunology at the UI Carver College of Medicine who also served the study as a co-leader stated that “the currently available vaccines against COVID-19 are very successful, but the majority of the world’s population is still unvaccinated and there is a critical need for more vaccines that are easy to use and effective at stopping disease and transmission. If this new COVID-19 vaccine proves effective in people, it may help block SARS-CoV-2 transmission and help control the COVID-19 pandemic.”
While vaccines administered as nasal spray are commonly used to immunize against influenza, a similar method still remains on paper against COVID-19. The vaccine used in the study has a single dose regime and can be stored at normal refrigerator temperatures for up to at least three months.
The nature of administration, through the nasal cavity, makes it easier to deliver even to those who are fearful of injections.
Speaking about the process, Prof. Biao He from the University of Georgia’s Department of Infectious Diseases in the College of Veterinary Medicine and co-leader of the study observed that “we have been developing this vaccine platform for more than 20 years, and we began working on new vaccine formulations to combat COVID-19 during the early days of the pandemic,” further adding that “Our preclinical data show that this vaccine not only protects against infection but also significantly reduces the chances of transmission.”
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.
The inhaled PIV5 vaccine developed by the team targets mucosal cells that line the nasal passages and airways. These cells are the main entry point for most SARS-CoV-2 infections and the site of early virus replication.
The study showed that the vaccine produced a localized immune response, involving antibodies and cellular immunity, that completely protected mice from fatal doses of coronavirus.
The vaccine also prevented infection and disease in ferrets and, importantly, appeared to block transmission of COVID-19 from infected ferrets to their unprotected and uninfected cage-mates.