Nasal Covid-19 vaccine shows encouraging result in animals: Study

A new study on an experimental intranasal Covid-19 vaccine showed that it protected mice from fatal doses of SARS-CoV-2 by creating antibodies in them and also blocked animal-to-animal transmission of the Covid-19 virus.

The study conducted by a team of researchers from the University of Iowa and the University of Georgia was published in the Science Advances journal on July 2.

The researchers used a harmless parainfluenza virus 5 (PIV5) to deliver the SARS-CoV-2 spike protein into the cells of the mice. Prompting an immune response in the mice, the vaccine produced a localised immune response, involving antibodies and cellular immunity.

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.

The vaccine also prevented infection and disease in ferrets and appeared to block transmission of Covid-19 from infected ferrets to their unprotected and uninfected cage-mates, the researchers said.

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The PIV vaccine targets the mucosal cells which are on the nasal passages and airways. That is the entry point of most SARS-CoV-2 infections and the site for replication.

Unlike the traditional Covid-19 vaccines which are double dose injections, this vaccine is a single dose nasal spray. This vaccine also comes with easy storage in normal refrigerator temperature for up to three months.

The intranasal spray is easy to administer and can be used in people who have a fear of needles.

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).

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"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," said Paul McCray, a professor of at University of Georgia, US.

"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," McCray, co-leader of the study, said.

"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," said Biao He, PhD, a professor in the University of Georgia’s Department of Infectious Diseases in the College of Veterinary Medicine and co-leader of the study, in a press release.

"Our preclinical data show that this vaccine not only protects against infection but also significantly reduces the chances of transmission,” he added.