Dr. Catherine Schuster-Bruce
A COVID-19 vaccine patch provided a better immune response than an injection in mice.
The patch introduces the vaccine into the skin, where there are more immune cells than muscles.
The vaccine will be tested on humans in 2022, the study’s lead author said.
An innovative vaccine patch could be more effective than an injection to provide protection against COVID-19, early-stage research suggests.
A study, led by researchers at the University of Queensland and published in Science Advances Friday, found that antibodies in mice were forty times higher after two doses of a COVID-19 vaccine were given via a skin patch compared to doses delivered via needle.
The patch triggered “significantly higher” antibody levels in the blood than an injection, even after one dose, the study’s authors said.
The antibodies generated by the vaccine patch worked against the previously dominant alpha and beta variants in the laboratory, they said. They did not test it against the highly contagious Delta variant, which is most common in the United States.
A single dose seemed to stop the virus from replicating in the brain and lungs, which was “remarkable” because the virus that causes COVID-19 can infect these body parts in mice and humans, they said.
Trials on humans will begin in 2022, says Dr. David Muller, a researcher at the Australian Infectious Diseases Research Center who led the study, told AFP.
Muller said vaccines delivered to the skin generally produced strong immune responses because the skin is “full of immune cells.” Muscles do not have many of the immune cells needed to respond to the vaccine, he said, according to AFP.
Burak Ozdoganlar, a professor of engineering at Carnegie Mellon University who has been working on patch vaccine technology since 2007 but was not involved in the study, told AFP that “less vaccine delivered precisely to the skin can activate an immune response similar to intramuscular injection.” This may mean that lower doses of vaccine are required to inoculate patients compared to an injection.
The technology also promises easier distribution than existing COVID-19 shots, less medical waste and less chance of accidental needle sticks, study authors said.
The so-called high-density microarray patch (HD-MAP) is a patch of one centimeter square with about 5,000 tips coated with vaccine. They are “so small you can’t see them,” Muller told AFP.
The patch is applied to the skin in two minutes using an applicator that looks like a hockey puck. Muller told The Times of London that the feeling of being vaccinated is “much like a good ‘flick’.”
The vaccine used on the patch, called HexaPro, uses a protein to trigger the immune response and was originally developed by researchers at the University of Texas. Separate clinical trials with the human vaccine – delivered by injection – have begun in Vietnam and Thailand.
Muller told the New Scientist that his team wanted to “come up with an alternative that would be stable long enough to cover the last mile, especially in resource-constrained settings.”
The study’s authors said that after the vaccine was applied to the patch, it appeared to be stable at room temperature for up to a month. Existing COVID-19 vaccines from Moderna and Pfizer were stable for between two hours and a week at the same temperature, they said.