Researchers at the University of Washington are excited about a potential new vaccine against COVID-19. It’s an RNA vaccine that produces antibodies against COVID-19 in mice and primates.
RNA is a molecule that tells cells what to build. An RNA vaccine injects code for part of the virus, an antigen, into a human cell. The cell then produces virus proteins that are displayed on the cell’s surface, like a jacket. This triggers the immune system to create antibodies.
Currently, there are no RNA vaccines on the market, but many are in development. UW’s RNA vaccine is different from the other ones in clinical trials because it’s a replicating RNA vaccine. Once it gets inside the cell, it makes multiple copies of itself, which results in the cell making more antigen. More antigen creates a stronger trigger to induce a stronger, potentially more sustained antibody response.
Unlike more conventional vaccines that often require two doses, this one, when tested in animals, is effective after one dose.
“This is the first time I've ever seen a nucleic acid vaccine induce protective levels of antibody in a monkey after only a single immunization. So, that was very exciting for us,” said Deborah Fuller, a microbiology professor at UW Medicine, and part of the research team working on this.
Unlike what’s been seen in convalescent humans, this antibody protection has not faded in the animals that have received a single dose. The level of antibodies generated was comparable to those in people who are recovering from COVID-19. Researchers believe these antibodies provide protection by messing with the spikes of the virus, preventing them from latching onto cells.
UW researchers also say this vaccine makes the body generate a T-cell response. T cells can help clear out what’s left of a virus that antibodies can’t fight off. The vaccine also is effective in treating younger and older mice. This gives scientists hope that it could be effective in the elderly, a population that is extremely vulnerable to COVID.
This work is being done in partnership with scientists at HDT, a Seattle-based biotechnology company. HDT has developed a nanoparticle that enables the vaccine to be shelf stable for up to a week.
Limited testing in humans is set to begin later this summer. UW researchers say, similar to many other vaccines in the works, they are on a compressed timeline on bringing this one to market in 18 months to two years, depending on how human trials go.
The findings of this research arepublished in the July 20 issue of Science Translational Medicine.
