COVID-19 inhaled vaccine prevents disease and transmission in animals

In a new study evaluating the potential of a single-dose intranasal COVID-19 vaccine, a team from the University of Iowa and the University of Georgia found that the vaccine fully protects mice against deadly infection to COVID-19. The vaccine also blocks the transmission of the virus from animal to animal. The results were published on July 2 in the journal Scientists progress.

“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, ”says Paul McCray, MD, professor of pediatrics-pulmonary medicine, microbiology and immunology at IU Carver College of Medicine, and study co-lead. “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. “

Unlike traditional vaccines which require an injection, this vaccine is administered through a nasal spray similar to those commonly used to vaccinate against influenza. The vaccine used in the study requires only one dose and can be stored at normal refrigerator temperature for at least three months. Because it is given intranasally, the vaccine may also be easier to administer, especially for those who are afraid of needles.

“We have been developing this vaccine platform for over 20 years and have started working on new vaccine formulations to fight COVID-19 during the early days of the pandemic,” said Biao He, Ph.D. ., professor at the University. of the Georgia Department of Infectious Diseases at the College of Veterinary Medicine and co-lead of the study. “Our preclinical data shows that this vaccine not only protects against infection, but also significantly reduces the risk of transmission.”

The investigational vaccine uses a harmless parainfluenza virus 5 (PIV5) to deliver the SARS-CoV-2 spike protein into cells where it causes a immune response that protects against infection with COVID-19. PIV5 is related to cold viruses and easily infects various mammals, including humans, without causing significant disease. The research 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 developed by the team targets the mucous cells that line the nasal passages and respiratory tract. These cells are the main entry point for most SARS-CoV-2 infections and the site of early replication of the virus. The virus produced in these cells can move deeper into the lungs and other organs in the body, which can lead to more serious illness. More, virus made in these cells can be easily excreted by exhalation, allowing transmission from one infected person to others.

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 most importantly seemed to block transmission of COVID-19 from infected ferrets to their unprotected and uninfected cage mates.