‘Like A Band-Aid’
UPMC Scientists Say Vaccine Ready For Human Trial
University of Pittsburgh School of Medicine scientists are ready to begin a human trial of a COVID-19 vaccine pending Food and Drug Administration approval.
A peer-reviewed study of the UPMC scientists’ research has been published in The Lancet’s EBioMedicine, the first peer-reviewed paper describing a possible vaccine for COVID-19.
The University of Pittsburgh researchers were able to work quickly on the vaccine because they had done some work during earlier coronavirus epidemics. When tested in mice, delivered through a fingertip-sized patch of microscopic needles, the vaccine produces antibodies specific to SARS-CoV-2 at quantities researchers think can neutralize the virus.
“Our process for making this vaccine does not require any overly complex or expensive equipment, so it is very scaleable,” said Dr. Louis Falo, professor and chair of dermatology at UPMC and the University of Pittsburgh School of Medicine during a virtual news conference Thursday. “At the present time in our lab, one person with a set of molds and a centrifuge can make hundreds of microneedle arrays in a single day. The other important feature is that unlike most other current vaccines, this vaccine does not need to be kept frozen or refrigerated. It is shelf stable at room temperature, like a Band-Aid. That reduces shipping costs and supports vaccine distribution.”
Clinical trials can take months or years, but Falo said researchers aren’t dealing with typical conditions. The National Institutes for Health, Food and Drug Administration and other regulatory agencies are working to accelerate the process during the COVID-19 pandemic.
“We are not trying to be evasive in terms of giving you a specific timeline,” Falo said in response to a question from The Post-Journal. “The regulatory process is iterative, so how long the regulatory process takes depends on the feedback we get during the process. What I can tell you is once we have been given approval we will be ready to go with the vaccine.”
A QUICK PROGRESSION
Dr. Andrea Gambotto, associate professor of surgery at the Pitt School of Medicine, said UPMC researchers had previous experience on SARS-CoV in 2003 and MERS-CoV in 2014 that taught researchers that a particular protein, called a spike protein, is important for inducing immunity against the virus.
With the MERS vaccine in 2014, researchers tested different platforms and determined that the sub-unit protein vaccine was as good as other genetic systems.
That work laid a baseline when genetic information about COVID-19 was discovered this year.
“When the genetic sequence for SARS-coronavirus-2 was published in late January of this year, we were able to plug into our existing tool and rapidly produce a vaccine,” Gambotto said. “We use a genetically engineered cell to take a piece of the spike protein on the outside of SARS-coronavirus-2 — this is the part of the virus that the immune system sees –and when that happens it triggers antibody production which should protect against viral infection and COVID-19 disease. This is how an annual flu shot works.”
Funding couldn’t be secured to continue prior research into the clinical trials phase. Gambotto said UPMC researchers were in a front line position in 2003 to proceed with clinical trials when funding for their research dried up after the SARS virus suddenly disappeared. The same thing happened in 2014 with the MERS-CoV.
“There was no interest,” Gambotto said. “2014 was pretty much the same story. We developed a vaccine and actually last year we did propose to run a clinical trial that in the end was not funded. We didn’t have the resources to move this vaccine beyond the pre-clinical implementation. With the MERS, we determined that the immunity we were getting from our vaccine did correlate with what one would expect what one would predict would be the response against SARS-coronavirus-2. We have selected this vaccine format because we believe it is one of the most broad-based and easy to translate to a vaccine.
HOW IT WORKS
PittCoVacc, short for Pittsburgh Coronavirus Vaccine, uses lab-made pieces of viral protein to build immunity.
The researchers also used a novel approach to deliver the drug, called a microneedle array, to increase potency. The array is a fingertip-sized patch of 400 tiny needles that delivers the spike protein pieces into the skin, where the immune reaction is strongest. The patch goes on like a Band-Aid and then the needles — which are made entirely of sugar and the protein pieces — dissolve into the skin.
“We use a genetically engineered cell to take a piece of the spike protein on the outside of SARS-coronavirus-2 — this is the part of the virus that the immune system sees — and when that happens it triggers antibody production which should protect against viral infection and COVID-19 disease,” Gambotto said. “This is how an annual flu shot works.”
The protein pieces are manufactured by a “cell factory” — or layers upon layers of cultured cells engineered to express the SARS-CoV-2 spike protein — that can be stacked further to multiply yield. Purifying the protein also can be done at industrial scale. Mass-producing the microneedle array involves spinning down the protein-sugar mixture into a mold using a centrifuge.
When tested in mice, PittCoVacc generated a surge of antibodies against SARS-CoV-2 within two weeks of the microneedle prick. The animals haven’t been tracked long-term yet, but the researchers point out that mice who got their MERS-CoV vaccine produced a sufficient level of antibodies to neutralize the virus for at least a year, and so far the antibody levels of the SARS-CoV-2 vaccinated animals seem to be following the same trend.
The SARS-CoV-2 microneedle vaccine maintains its potency even after being thoroughly sterilized with gamma radiation — something the doctors said is a key step toward making a product that’s suitable for use in humans.
IS IT SAFE?
Falo said the vaccine should be safe for all age groups and for those with certain medical conditions because it provides a low dose of antigen — lower, in fact, than flu vaccines deliver each year — and delivers it to a confined space within the skin. That means that the PittCoVacc may not lead some people to experience symptoms when taking the vaccine as sometimes happens when people feel flu symptoms after they get a flu shot.
“It is very unlikely we will see type of systemic responses that have been seen in some patients in the flu vaccine,” Falo said. “I believe that this vaccine should be effective across all age groups. As we learned with flu, it may require a slightly higher dose for elderly patients but that has yet to be tested with this particular vaccine.”
While federal officials and the country at large want to see a vaccine developed quickly, Falo said it is important that the vaccine be safe. That means the researchers don’t want to move so quickly that they possibly miss side effects or negative reactions people may experience should they end up taking the vaccine.
“What you’re pointing out is there is a reason these trials take the length of time that they do,” Falo said. “We’re taking every precaution, and you’ll see in all of the trials that develop over the next months that safety is our top concern.”