In 2017, when the FDA approved the first gene therapy to treat an inherited retinal disease, bold predictions followed that this new technology would lead to treatments for other, more common conditions, such as age-related macular degeneration. But no one predicted this: The viral vector technique developed for the first gene therapy to cure blindness may also be the key to a vaccine to prevent COVID-19.
Massachusetts Eye and Ear and Massachusetts General Hospital announced exciting progress this week in the development of an experimental vaccine called AAVCOVID, a novel gene-based vaccine candidate against SARS-CoV2, the virus that causes COVID-19. This strategy uses the FDA-approved gene transfer technology, the adeno-associated viral (AAV) vector, to deliver genetic sequences of the SARS-CoV-2 Spike antigen so the body can develop an immune response to the coronavirus. It is currently in preclinical development with a plan to begin clinical testing in humans later this year.
The AAVCOVID vaccine program was developed in the laboratory of Luk H. Vandenberghe, PhD, director of the Grousbeck Gene Therapy Center at Massachusetts Eye and Ear and Associate Professor of Ophthalmology at Harvard Medical School. Vandenberghe set to work on this vaccine candidate in mid-January, basing it on an AAV vector that he developed 15 years ago while at the University of Pennsylvania. But unlike viral vectors for gene therapy, this vector elicits an immune response, which in gene therapy is a bad thing, but in the vaccine world is ideal.
AAV technology offers a few advantages over other vaccine strategies currently under development: its adaptability and potential to elicit a beneficial immune response in people, and its safety record as demonstrated by the FDA-approved gene therapy.
“AAV is a superior technology for safe and efficient gene delivery, and the unique technologies we are applying in AAVCOVID support the potential for a potent immunity to be induced to SARS-CoV-2 from a single injection,” said Dr. Vandenberghe. “In a crisis, we can harness the power of molecular biology and develop a draft of a vaccine in weeks, and that’s what was done here. Now, clinical studies are needed to establish safety and efficacy of our novel approach,” he said.
“The coronavirus pandemic has challenged us in many ways, as we care for our patients while keeping our workforce and community safe, in an environment of increasing economic uncertainty,” said Joan W. Miller, MD, Chief of Ophthalmology at Mass. Eye and Ear, Massachusetts General Hospital, and Brigham and Women’s Hospital. “Luk Vandenberghe’s program to develop a gene-based AAV vaccine against SARS-CoV2 is a ray of brightness and hope for all of us in these dark times.”
The AAVCOVID vaccine candidate will be administered by an intramuscular injection. Currently, tests are underway in animal models, and initial manufacturing activities have begun. Based on the preclinical findings, one or more candidates will advance into the clinical phase of testing in humans.