First vaccine against SARS virus family enters human trials

A vaccine intended to broadly protect against COVID-19 and related coronaviruses — including some that haven’t yet jumped from animals to people — has begun clinical testing in Australia. 

The vaccine candidate builds upon a self-assembling nanoparticle technology developed by researchers at the UW Medicine and its Institute for Protein Design. The South Korean pharmaceutical company SK bioscience is bringing the vaccine, called GBP511, to human clinical trial. 

“GBP511 is the first vaccine to reach human testing that is intended to protect against multiple strains of the virus that causes COVID-19 as well as related coronaviruses with the potential to spark dangerous outbreaks,” said Neil King, associate professor of biochemistry at UW Medicine and co-inventor of the nanoparticle platform underlying the vaccine. The clinical trial is an important step towards vaccines that guard against a family of viruses, not just individual types or strains. 

Coronaviruses have caused three major disease outbreaks in the past two decades: SARS (severe acute respiratory syndrome), MERS (Middle East respiratory syndrome), and COVID-19 (coronavirus disease of 2019).

Sarbecoviruses refer to a particular group of coronaviruses. They include SARS-CoV-2, the virus that causes COVID-19; the original SARS-CoV-1 virus which caused the 2002-2004 outbreak of respiratory disease; MERS-CoV, found mostly in camels but transmittable to and between people; and numerous bat coronaviruses with pandemic potential. 

The vaccine’s core is a computer-designed protein particle. It is a precise molecular assembly that does not exist in nature. To turn it into a vaccine, scientists at UW Medicine attached four immune-system cues from different coronaviruses — two from SARS-CoV-2, one from SARS-CoV-1, and one from a bat coronavirus, BtKY72. 

“The beauty of this approach is that by presenting the immune system with multiple related antigens at once, we can train it to recognize features that are conserved across the entire sarbecovirus family,” said David Veesler, professor of biochemistry at UW Medicine and a Howard Hughes Medical Institute Investigator, who led the preclinical studies. “That’s exactly what you need to prepare for unpredictable future threats.” 

In preclinical studies, GBP511 protected animals from related viruses they weren’t directly immunized against. 

The international Phase 1/2 trial, which began enrollment last month, will evaluate safety and immune responses in approximately 368 healthy adults in Perth, Western Australia. The study will include comparisons with Comirnaty, an mRNA COVID vaccine currently in clinical use. Results are expected by 2028. 

In a statement from SK bioscience, CEO Jaeyong Ahn said, “Developing a universal sarbecovirus vaccine is a critical challenge that must be addressed to prepare for the next pandemic.”

GBP511 builds on technology validated through SKYCovione, a COVID-19 vaccine that in 2022 became the world’s first computer-designed medicine to achieve regulatory approval. That approach to vaccine design was pioneered by the King and Veesler Labs at UW Medicine and developed by SK bioscience. 

The underlying nanoparticle platform developed at the Institute for Protein Design has been validated in peer-reviewed studies. These include a 2021 Cell paper showing that animals immunized with multivalent nanoparticle vaccines were protected against coronaviruses not included in the vaccine itself. A 2025 preprint describes the preclinical work that led to GBP511. 

The Coalition for Epidemic Preparedness Innovations (CEPI) has supported the GBP511 program with approximately $65 million in funding. 

Additional vaccines that use this platform are being developed, including FluMos-v2, a next-generation influenza vaccine candidate now in Phase 1 clinical trials at the NIH. FluMos-v2 displays antigens from six influenza strains, thereby expanding on the four-strain approach used in the earlier FluMos-v1 vaccine. The goal is to provide a wider scope of protection against future flu outbreaks.

Adapted from an article by Ian C. Haydon, Institute for Protein Design.

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