Phase 3 clinical trial: second-generation new crown vaccine produces high levels of neutralizing antibodies

The novel coronavirus infection (COVID-19 virus) vaccine developed by the University of Washington School of Medicine has been shown to be safe and effective in late-stage clinical trials

Seattle scientists working on a new vaccine are trying to create a "second-generation" COVID-19 vaccine that is safe, effective in low doses, easy to manufacture on a large scale, and doesn't require deep freezing

If GPB510 receives full regulatory approval, it will be available through COVAX, an international effort to equitably distribute COVID vaccines around the world

The University of Washington will license vaccine technology for free during the pandemic

A multinational Phase 3 clinical trial involving 4,037 adults over the age of 18 found that the vaccine, called GPB510, produced higher levels of protective antibodies than the Oxford/AstraZeneca vaccine Vaxzevria

In addition, GPB510 had a higher "antibody conversion rate," the proportion of subjects with a 4-fold or greater increase in neutralizing antibody levels after vaccination

The level of T cell activation that protects the body from COVID-19 is also similar to or higher than GBP510

SK Life Sciences' Phase 1/2 clinical trial results published in November this year and announced in March this year showed that GPB510 was safe in all trial participants who received the adjuvanted vaccine and produced virus-neutralizing antibodies

Unlike the earliest approved COVID-19 vaccines that used mRNA, viral vectors or inactivated virus, GPB510 is made of proteins that form tiny particles dotted with fragments of the pandemic coronavirus

"This vaccine was designed at the molecular level to deliver a key part of the coronavirus spike protein to the immune system

Two labs in the Department of Biochemistry at the University of Washington School of Medicine led the initial development of protein-based vaccines: King's lab pioneered self-assembling protein nanoparticle technology for vaccines, and Weisler's lab identified SARS-CoV-2 A key fragment of the Spike protein and integrated into nanoparticles

David Whistler, associate professor of biochemistry at Whistler University School of Medicine and HHMI researcher, has been studying the coronavirus since 2015

In 2016, scientists at the King lab at the UW School of Medicine set out to develop a strategy to create a new type of vaccine

Working together in the early months of the COVID-19 pandemic, researchers from the two labs designed a protein nanoparticle decorated with 60 copies of the receptor-binding domain of the Spike protein

"In order to focus the antibody response where it matters most, we decided to include only a key segment of the coronavirus spike protein, called the receptor-binding domain, in the vaccine," Wiessler said.

In preliminary animal studies reported in the journal Cell in late 2020, the nanoparticle vaccine was found to produce high levels of virus-neutralizing antibodies at low doses
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The antibodies target several different sites on the coronavirus spike protein, an ideal quality that could potentially enhance protection against future coronavirus variants
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Further preclinical studies, published in the journal Nature, also showed that the vaccine produced strong protection in non-human primates and generated a strong B cell response, which may improve the vaccine's continued protection.
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In a recent preprint, a third dose of the vaccine was found to provide robust protection against the COVID-19 Omicron variant in animals
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SK Biosciences will soon begin a third-dose trial in 750 adults
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Courtesy of the University of Washington School of Medicine