A COVID-19 vaccine based on technology developed at the University of Washington’s School of Medicine in Seattle has been approved by the Korean Ministry of Food and Drug Safety for use in individuals 18 years of age and older.
The vaccine became the first clinical therapeutic approved for use in people to emerge from protein design efforts at UW Medicine.
The protein-based vaccine was found to be more effective than the Oxford/AstraZeneca vaccine sold under the brand names Covishield and Vaxzevria.
SK bioscience, the South Korean company leading the vaccine’s clinical development abroad, has trademarked its version SKYCovione.
SK bioscience is now seeking approval for SKYCovione’s use in the United Kingdom and beyond. If approved by the World Health Organization, the vaccine will be made available through COVAX, an abbreviation for COVID-19 Vaccines Global Access. COVAX is an international effort to equitably distribute COVID-19 vaccines around the world. In addition, the South Korean government has agreed to purchase 10 million doses for domestic use.
The Seattle scientists behind the new vaccine sought to create a second-generation COVID-19 vaccine that is safe, effective at low doses, simple to manufacture, and stable without deep freezing. These attributes could enable vaccination at a global scale by reaching people in areas where medical, transportation, and storage resources are difficult to obtain.
“We know more than 2 billion people worldwide have not received a single dose of vaccine,” said David Veesler, associate professor of biochemistry at UW School of Medicine and co-developer of the vaccine. “If our vaccine is distributed through COVAX, it will allow it to reach people who need access.”
The University of Washington is licensing the vaccine technology royalty-free for the duration of the pandemic.
A multinational Phase 3 trial involving 4,037 adults over 18 years of age found that the SKYCovione vaccine elicits roughly three times more neutralizing antibodies than the Oxford/AstraZeneca vaccine Covishield/Vaxzevria. In these studies, SKYCovione or Covishield/Vaxzevria was administered twice with an interval of four weeks.
The antibody conversion rate, which refers to the proportion of subjects whose virus-neutralizing antibody level increased fourfold or more after vaccination, was higher with SKYCovione. According to data collected by SK bioscience, 98% of subjects achieved antibody conversion, compared to 87% for the control vaccine.
Among study participants 65 years of age or older, the antibody conversion rate of those vaccinated with SKYCovione was over 95 percent, which was a significant difference compared to the control vaccine (about 79% for the elderly). This finding raises the expectation that SKYCovione can be used effectively to protect the elderly.
The Phase 3 trial also found that the activation levels for T cells, which help protect the body from COVID-19, were similar or higher with SKYCovione.
SKYCovione is made of proteins that form tiny particles studded with fragments of the pandemic coronavirus. These nanoparticles were designed by scientists at UW Medicine and advanced into clinical trials by SK bioscience and GlaxoSmithKline with financial support from the Coalition for Epidemic Preparedness Innovations. SKYCovione includes GlaxoSmithKline’s pandemic adjuvant, AS03.
“This vaccine was designed at the molecular level to present the immune system with a key part of the coronavirus spike protein. We know this part, called the receptor-binding domain, is targeted by the most potent antibodies,” said Neil King, assistant professor of biochemistry at the UW School of Medicine and co-developer of the vaccine.
Two laboratories in the UW School of Medicine Department of Biochemistry led the initial development of the protein-based vaccine: the King Lab pioneered the vaccine’s self-assembling protein nanoparticle technology while the Veesler Lab identified and integrated a key fragment of the SARS-CoV-2 Spike protein onto the nanoparticles.
In 2016, scientists in the King lab at the UW Medicine Institute for Protein Design began developing a strategy for building a new type of vaccine. They designed proteins that self-assemble into precise spherical particles and later showed that these nanoparticles could be decorated with proteins from a virus.
Researchers from the two labs worked together in the earliest months of the COVID-19 pandemic to design a protein nanoparticle decorated with 60 copies of the Spike protein receptor-binding domain. The designed nanostructure mimics the repetitive nature of proteins on the surface of viruses, a property that the immune system responds strongly to.
“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,” Veesler said.
In a recent preprint, a third dose of the vaccine was found to confer strong protection against the omicron variant of COVID-19 in animals. SK bioscience will begin testing third doses in 750 human adults soon.
This press release was provided by University of Washington Medicine.