A fingertip-sized patch could be a potential vaccine for coronavirus, researchers say.
Scientists suggest that when tested in mice, it produced antibodies specific to Covid-19 in quantities thought to be sufficient for neutralising the virus.
The vaccine is described in a paper published in EBioMedicine, which is published by The Lancet, and is thought to be the first to be reviewed by other scientists.
Researchers at the University of Pittsburgh School of Medicine say they were able to act quickly because they had laid the groundwork during earlier coronavirus epidemics.
Co-senior author Andrea Gambotto, associate professor of surgery at the university, said: “We had previous experience on 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.
“That’s why it’s important to fund vaccine research. You never know where the next pandemic will come from.”
The researchers say their vaccine candidate follows a more established approach compared to the experimental mRNA vaccine candidate that has entered clinical trials in Seattle.
They have called their drug PittCoVacc, short for Pittsburgh Coronavirus Vaccine, and it uses lab-made pieces of viral protein to build immunity – the same way that current flu jabs work.
The researchers also used a novel approach to deliver the drug, called a microneedle array, to increase potency.
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 is applied like a plaster and then the needles, which are made entirely of sugar and the protein pieces, simply dissolve into the skin.
Co-senior author Louis Falo, professor and chair of dermatology at the School of Medicine and University of Pittsburgh Medical Centre, said: “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.
“And it’s actually pretty painless – it feels kind of like Velcro.”
Researchers say their system can be mass produced, and once manufactured, the vaccine can sit at room temperature until it is needed, eliminating the need for refrigeration during transport or storage.
According to the study, when tested in mice, PittCoVacc generated a surge of antibodies against Sars-CoV-2 within two weeks of the microneedle prick.
The authors are now in the process of applying for an investigational new drug approval from the US Food and Drug Administration in anticipation of starting a phase I human clinical trial in the next few months.