The vaccination rate in Switzerland is stagnating at under 70 percent. Some have reservations about the safety of the vaccines. Others are simply afraid of the injection. Exactly that should no longer be a problem in the future: Researchers are working on vaccinations using plasters instead of syringes.
A team from Australia and the USA has now published promising results from experiments with mice in the journal “Science Advances”. The researchers fitted plastic plasters with an area of one square centimeter with more than 5,000 microscopic spines, “so tiny that you can’t even see them,” explains virologist David Muller from the University of Queensland in Australia.
Patches are more effective than syringes
The tips were coated with an experimental vaccine and the plaster stuck on with an applicator. “It feels like getting a snap on your skin,” says Muller. The researchers used a so-called subunit vaccine that reproduces the spike protein specific for the SARS Cov-2 virus.
The mice were vaccinated for two minutes through the patch or with a syringe. The immune system of the mice that were injected with the vaccine through the patch produced high levels of neutralizing antibodies after two doses – “also in the lungs, which is important for Covid-19,” the researcher describes. According to Muller, the results exceeded those of the needle vaccination by far.
Patches are more effective than syringe vaccination because the latter is usually injected into the muscles, where few of the immune cells needed to respond to the vaccine are located. In addition, according to the researchers, the tiny spines in the vaccine plaster cause the skin beneath it to die off, which alarms the body and triggers a greater immune response.
Patch vaccine has a longer shelf life
In addition, the vaccine applied dry to the patch remains stable at 25 degrees for a month and at 40 degrees for a week – in contrast to the vaccines from Biontech / Pfizer or Moderna, which only last a few hours at room temperature. This means less dependence on the cold chain, which is often not guaranteed in developing countries. Also, according to Muller, the vaccine patch is “incredibly easy to administer” because it does not require trained health workers.
Burak Ozdoganlar, professor of engineering in Pittsburgh, sees another advantage: “A smaller amount of vaccine, precisely applied to the skin, can produce an immune response similar to an intramuscular injection,” he emphasizes. At a time when vaccines are scarce, this is an important factor.
Last but not least, the vaccine patches help immunize people who are afraid of injections or children with practically no pain. The patch used in the new study was made by the Australian company Vaxxas, which is the furthest in development.
Soon experiments on humans
The first human trials are planned for April. The two US companies Micron Biomedical and Vaxess are also in the running. Vaxess in Massachusetts is working on a patch that uses microneedles to dissolve into the skin. Next summer, the company plans to vaccinate 2,000 to 3,000 people with a patch in clinical trials. The biggest challenge at the moment is production: So far, no manufacturer has been able to produce the patches in large quantities.
Vaxess managing director Michael Schrader is nevertheless optimistic. The corona pandemic gave the emerging industry a boost, he says. “That’s the future. Over the next decade, the way vaccines are distributed around the world will change radically. ” (SDA / sfa)