UW Medicine's COVID-19 Vaccine Succeeds In Phase 3 Testing

SEATTLE — A COVID-19 vaccine developed at the University of Washington could end up being used to battle the pandemic halfway across the world in as little as a month.

UW Medicine reported Monday that its vaccine, called GPB510, has proven effective at treating COVID-19 in Phase 3 clinical testing. SK bioscience, the lead company supporting the vaccine's development, will ask for permission to deploy the vaccine starting in South Korea within the coming few weeks. If successful, the South Korean government has agreed to purchase at least 10 million doses.

Researchers say their second-generation vaccine should be effective at low-doses, safe, and simple to manufacture on a large scale, but it has one other major benefit: it's not an RNA vaccine, so it is stable without deep-freezing. Currently-approved vaccines like Moderna and Pfizer-BioNTech vaccines have to be kept cold to remain effective.

More than 2 billion people worldwide have yet to receive a single dose of COVID-19 vaccine, many of whom live in areas that do not have stable access to medical facilities, transportation, or the technology to store frozen vaccines for a long period of time. Because GPB510 eliminates some of those hurdles, it could be a game-changer.

"This particular protein nanoparticle vaccine will probably have advantages in cost of production and storage stability, meaning that it may be easier to make at scale and supply in the developing world," said Neil King, Assistant Professor of Biochemistry for the UW School of Medicine.

If GPB510 is approved by regulators, UW Medicine says it will be distributed via COVAX, an international effort to bring vaccines to developing nations, which benefits the whole world.

"If we want to limit the emergence of new variants, we need to make sure that everyone has access to vaccines and not only developed countries having access to multiple boosters," said David Veesler, Associate Professor of Biochemistry, at the UW School of Medicine.

UW Medicine's latest vaccine trial involved 4,037 adults, who received a dose of either GPB510 or Oxford/AstraZeneca vaccine twice over four weeks. Researchers say those who took GPB510 had higher levels of protective antibodies than the AstraZeneca vaccine.

“In order to focus the antibody response where it matters most, we decided to include in the vaccine only a key fragment of the coronavirus spike protein, known as the receptor-binding domain,” said Veesler. “We are thrilled to see that this strategy paid off and has led to a successful subunit vaccine.”

While SK bioscience waits for permission from South Korea to deploy the first wave of GPB510 vaccines, it will also begin testing third doses in another 750 adults soon, UW said.