Coronaviruses constitute a large family of RNA viruses that infect a broad range of mammalian and avian species, primarily causing respiratory and enteric diseases. The most recent coronavirus, SARS-CoV-2 is the third highly pathogenic member to infect humans in the past two decades and was declared a pandemic by the WHO in March of 2020. SARS-CoV-2 has infected more than 30 million people worldwide and has a death toll over one million. The race to develop a SARS-CoV-2 vaccine is advancing at unprecedented speeds, with 40 candidates in clinical trials and another 92 in preclinical stages. Ultimately, there will likely need to be multiple vaccines to successfully protect the global community.
Attenuated recombinant poxviruses are promising vaccine vectors, with many entering into clinical trials for a host of diseases. They have demonstrated excellent safety profiles in addition to their ability to induce a protective immune response to foreign expressed antigens. However, there is a general consensus that improvements to their immunogenicity are needed.
Researchers at the Biodesign Institute of Arizona State University have developed a novel SARS-CoV-2 vaccine using recombinant attenuated poxvirus vectors that express SARS-CoV-2 antigens. The vectors have been modified to possess increased immunogenicity in order to stimulate protective systemic and mucosal immunity. When tested in mice, SARS-CoV-2 neutralizing antibodies were generated, both in mice vaccinated with these vectors, and in mice vaccinated with plant derived VLPs and boosted with these vectors.
These vectors represent another promising vaccine candidate to add to the growing arsenal that is being developed to respond to the current coronavirus pandemic.
- SARS-CoV-2 vaccine compositions
- Other virus vaccine compositions, including emergent coronaviruses
Benefits and Advantages
- Increased immunogenicity
- Shown to generate SARS-CoV-2 neutralizing antibodies in mice
- Attenuated vector for enhanced safety profile
- Could be modified to express foreign antigens for other viruses, including other coronaviruses
- Incorporates transcription/translation enhancers