The first set of tests in mice of a potential vaccine to prevent COVID-19 has shown it can spur the animals’ immune systems to produce antibodies against the coronavirus.
The vaccine is delivered via a fingertip-sized, Band-Aid-like patch made of 400 tiny needles that scratch the skin. The researchers who are developing the vaccine say the immune system reacts more readily to irritations of the skin, which means doing so could trigger it to target the coronavirus.
When tested on mice, they developed antibodies to fight the coronavirus within two weeks.
The researchers said in a study published in the medical journal EBioMedicine that they had already been at work on vaccines to fight the two other deadlier coronavirus strains: SARS, which broke out in China in 2003, and MERS, which hit Middle Eastern countries and South Korea 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,” co-senior author Andrea Gambotto, M.D., associate professor of surgery at the Pitt School of Medicine, said in a statement.
“The researchers also used a novel approach to deliver the drug, called a microneedle array, to increase potency,” the statement said. “This 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 — simply dissolve into the skin.”
“We developed this to build on the original scratch method used to deliver the smallpox vaccine to the skin, but as a high-tech version that is more efficient and reproducible patient to patient,” said co-senior author Louis Falo, M.D., Ph.D., professor and chair of dermatology at Pitt’s School of Medicine and UPMC. “And it’s actually pretty painless — it feels kind of like Velcro.”
The newly tested mice have not 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.”
“Importantly, the SARS-CoV-2 microneedle vaccine maintains its potency even after being thoroughly sterilized with gamma radiation — a key step toward making a product that’s suitable for use in humans,” they said.
But final release of a vaccine is still a while away.
“Testing in patients would typically require at least a year and probably longer,” Falo said. “This particular situation is different from anything we’ve ever seen, so we don’t know how long the clinical development process will take. Recently announced revisions to the normal processes suggest we may be able to advance this faster.”
Yet the researchers are optimistic that new testing techniques mean developing vaccines for any type of emerging virus can be done more quickly.
“Taken together, our studies demonstrate the speed at which vaccines against emerging infections can be designed and produced using the recent advances in recombinant DNA technology. Combining emerging biotechnology methods with bioengineering advances in vaccine delivery strategies, it may now be possible to rapidly produce clinically-translatable vaccines against novel pathogens for human testing and subsequent global distribution in time to significantly impact the spread of disease,” they wrote.
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