By SUSAN JONES
Pitt School of Medicine researchers announced at a news conference today a potential vaccine against SARS-CoV-2, the novel coronavirus causing the COVID-19 pandemic, that would work the same way as current flu shots to build up antibodies to the disease.
When tested in mice, the vaccine, delivered through a fingertip-sized patch, produces antibodies specific to SARS-CoV-2 at quantities thought to be sufficient for neutralizing the virus.
“We used a genetically engineered cell to make a piece of the spike protein on the outside of SARS coronavirus,” said co-senior author Andrea Gambotto, associate professor of surgery at the Pitt School of Medicine. “This is the part of the virus that the immune system sees, and when that happened it triggered antibody production, which should protect against viral infection and COVID-19 disease.”
The antigen is delivered through a dissolvable microneedle array directly into those areas of the skin that are made to make an immune response, said co-senior author Louis Falo, professor and chair of dermatology at Pitt’s School of Medicine and UPMC. “And so it results in a very potent vaccine. When you're thinking about how these micronano arrays are actually used in practice, think about them as almost like a Bandaid. The microneedle array is simply applied to the skin topically, pressed into place very shortly. And then taken off and thrown away. And then the antigen is already delivered.
“This vaccine is designed to be safe, in part because it delivers very low doses of antigens, so much lower doses than the traditional flu vaccine,” Falo said. “Secondly, it delivers that antigen to a very confined space within the skin, so that it's very unlikely that we would see any type of systemic responses that have been seen with some patients in the flu vaccine.”
The authors are now in the process of applying for an investigational new drug approval from the U.S. Food and Drug Administration in anticipation of starting a phase I human clinical trial in the next few months.
“This process normally takes months to years, but these pandemic conditions are not normal,” Falo said. “The NIH, the FDA and other regulatory agencies have made terrific progress in accelerating this process. Once we get approval from the FDA, we will be ready to start human safety trials.”
The researchers were quizzed several times about a timeline for delivering the vaccine to the public but said that can’t be determined yet because of the regulatory requirements and testing needed.
“We're hoping with the expedited review and all the efforts that the regulatory agencies have made that we can reduce that regulatory process from months to weeks,” Falo said.
Once human testing is approved, “we will be starting with healthy volunteers in the Pittsburgh area,” he said. “Those will be the first cohorts of patients that enter the trial. And we will be basically looking at multiple doses during the course of the trial to find the most effective dose.”
The scientists started working on the vaccine on Jan. 21 and were able to act quickly because they had already laid the groundwork during earlier coronavirus epidemics — SARS-CoV in 2003 and MERS-CoV in 2014.
“These two viruses, which are closely related to SARS-CoV-2, teach us that a particular protein, called a spike protein, is important for inducing immunity against the virus. We knew exactly where to fight this new virus,” Gambotto said.
The Pitt scientist’s work appeared today in EBioMedicine, which is published by The Lancet. It is the first study to be published about a possible COVID-19 vaccine after critique from fellow scientists at outside institutions.
Compared to the experimental mRNA vaccine candidate that just entered clinical trials, the vaccine described in this paper — which the authors are calling PittCoVacc, short for Pittsburgh Coronavirus Vaccine — follows a more established approach, using lab-made pieces of viral protein to build immunity. It’s the same way the current flu shots work.
When tested in mice, PittCoVacc generated a surge of antibodies against SARS-CoV-2 within two weeks of the microneedle prick.
“This vaccine is the result of a collaboration involving scientists from very diverse fields — vaccinologists, skin biologists, bioengineers and biologists — all coming together to work towards a common goal. That's the type of collaborative environment we have here at Pitt and at UPMC,” Falo said at the news conference.
The potential vaccine and delivery system are highly scalable, according to the researchers. Once manufactured, the vaccine can sit at room temperature until it’s needed, eliminating the need for refrigeration during transport or storage.
“For most vaccines, you don’t need to address scalability to begin with,” Gambotto said. “But when you try to develop a vaccine quickly against a pandemic that’s the first requirement.”
Additional authors on the study are Eun Kim, Geza Erdos, Shaohua Huang, Thomas Kenniston, Stephen Balmert, Cara Donahue Carey, Michael Epperly, William Klimstra, and Emrullah Korkmaz, all of Pitt; and Bart Haagmans, of Erasmus Medical Center.
Funding for this study was provided by the National Institute of Allergy and Infectious Diseases, the National Institute of Arthritis and Musculoskeletal and Skin Diseases and the National Cancer Institute.
Susan Jones is editor of the University Times. Reach her at email@example.com or 412-648-4294.
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