Since the start of the Covid pandemic, researchers have stepped up their attempts to develop patches that deliver life-saving pharmaceuticals to the skin without the use of needles, a technique that could change medicine.
The strategy could benefit those who are afraid of syringes and save children’s tears in doctor’s offices.
Skin patches could also help with vaccine distribution because they don’t require a cold chain, and they may even improve vaccination efficacy.
Promising results says study
A new mouse study published in Science Advances demonstrated promising results in this area.
The Australian-American researchers utilised one-square-centimeter patches peppered with over 5,000 miniscule spikes that were “so little you can’t see them,” said to David Muller, a virologist at the University of Queensland and co-author of the paper.
These tips have been coated with an experimental vaccination, and the patch is applied with a hockey puck-shaped applicator. “It’s like getting a good flick on the skin,” Muller explained.
The researchers utilised a vaccination known as a “subunit,” which mimics the coronavirus’s spikes on the surface.
Mice were injected with a syringe or through a patch over a two-minute period.
After two doses, those who received the patch produced large amounts of neutralising antibodies, including in their lungs, which is critical for stopping Covid, and the patches outperformed syringes.
The researchers also discovered that a subset of mice who had only one dosage of vaccine containing an adjuvant, a chemical that boosts immune response, “didn’t get sick at all,” according to Muller.
What makes them more effective?
Vaccines are typically injected into our muscles, but muscular tissue lacks the immune cells required to respond to the medicine, according to Muller.
Furthermore, the small increases cause localised skin death, signalling a problem and triggering a stronger immune response.
The logistical advantages for the scientist are unmistakable
First, the vaccine is stable for at least 30 days at 25 degrees Celsius (77 degrees Fahrenheit) and one week at 40 degrees Celsius (104 degrees Fahrenheit) when dry-coated on a patch, compared to a few hours at room temperature for the Moderna and Pfizer vaccines.
This is a huge benefit, especially for underdeveloped countries.
Second, “it’s incredibly easy to use,” according to Muller. “It doesn’t have to be delivered by highly qualified medical personnel.”
Since then, scientists have been hard at work
Burak Ozdoganlar, an engineering professor at Carnegie Mellon University in Pittsburgh, Pennsylvania, has been working on the technique since 2007.
Another advantage, he says, is that “a smaller amount of vaccine given precisely to the skin can elicit an immune response similar to intramuscular injection.” It’s a crucial factor because the impoverished world is having trouble getting enough Covid vaccination.
Ozdoganlar’s lab can create 300-400 patches each day, but he hasn’t been allowed to test them on mRNA vaccinations, which have been popular during the epidemic, because he hasn’t been given permission by Pfizer or Moderna.
In the near future
The patch used in the study published on Friday was created by Vaxxas, an Australian business that is the most advanced. Human trials will begin in April.
Micron Biomedical and Vaxess are two additional American companies competing in the event.
The latter, which was created in 2013 and is based in Massachusetts, is developing a patch with microneedles that dissolve in the skin.
They say this approach has the benefit of requiring fewer spikes per patch – just 121 – made of a protein polymer that is biocompatible.
“We’re working on a seasonal Covid and flu combination product that will be mailed directly to patients’ homes, for self-administration,” CEO Michael Schrader told AFP.
Covid vaccine they are using is produced by the company Medigen
Vaxess has just opened a factory near Boston, with funding from the US National Institutes for Health.
They aim to produce enough patches to vaccinate 2,000 to 3,000 people in clinical trials, which are to be launched next summer.
The main challenge right now is production, with no manufacturers yet able to make enough patches en masse.
“If you want to launch a vaccine you have to produce hundreds of millions,” said Schrader. “We do not have that scale as of today – no one really has that scale.”
But the pandemic has given a push to the nascent industry, which is now attracting more investors, he added.