Rodents that were given two doses of the vaccine had antibody and T-cell responses that were strong enough to suppress SARS-CoV-2, the coronavirus that causes COVID-19.
The vaccine also reduced lung damage, inflammation and disease severity in the rodents, according to scientists from Lancaster University in England and Texas Biomedical Research Institute in San Antonio.
“We found that administering this vaccine through a nasal spray completely protected the animals from shedding the virus which causes transmission of the virus. This means the immunization of the upper respiratory tract through a nasal spray can prevent individuals from spreading the virus and developing infections elsewhere in the body,” said study author Muhammad Munir, a Lancaster University virologist.
“Though the vaccine showed promising safety and efficacy in this animal model, human trials are still required to determine its applicability and to obtain regulatory approvals,” Munir added in a university news release.
The nasal spray vaccine is based on a common poultry virus called the Newcastle Disease Virus (NDV), which can replicate in humans but is harmless. The research team engineered NDV to produce the spike proteins of the SARS-CoV-2 virus to prime the body’s immune system to attack the coronavirus.
Their findings were published recently on BioRxiv, a preprint server for research that hasn’t yet been peer-reviewed.
There are a number of advantages to a nasal spray vaccine, including it being noninvasive, triggering local immunity, and being an alternative for people who are afraid of needles or have blood clotting disorders, according to the researchers.
They noted that there’s already a nasal spray vaccine for seasonal flu, so this type of vaccination has been proven to be effective.
A nasal spray vaccine for COVID-19 could provide a low-cost alternative for the developing world, because it could be produced using existing worldwide infrastructure for seasonal flu virus vaccines, the researchers suggested.
“The scalability and economical production make this vaccine candidate suitable for low- and middle-income countries,” said study author Mohammed Rohaim, also from Lancaster University.
The U.S. Centers for Disease Control and Prevention has more on COVID-19 vaccines.
SOURCE: Lancaster University, news release, Jan. 13, 2021