04 October 2021
American scientists say they have created a vaccine patch that provides greater protection against infectious diseases than traditional injections.
A 3D printer is used to make the patch, which is smaller than the tip of a finger. Each patch – which contains many small "micro-needles" – can be put directly on the skin.
The researchers said in a statement the experiments showed the patch provided an immune response 10 times greater than vaccines injected into arm muscles. And they reported it offered an immune response 50 times greater than vaccines injected under the skin.
The tests were carried out on mice, with plans to expand the experiments to humans.
The results were recently described in a study published in Proceedings of the National Academy of Sciences (PNAS). The team was led by scientists from Stanford University and the University of North Carolina (UNC) at Chapel Hill.
The researchers say the increased effectiveness happens because the patch releases substances directly into the skin, which is full of immune cells that are targeted by vaccines.
The scientists say that in addition to the patch vaccine being better at fighting disease, it has several other advantages over traditional injections. The patch is painless, does not require cold storage and can be given by individuals themselves.
The COVID-19 pandemic has demonstrated the importance of vaccines as a way to control viruses in massive populations. But there are barriers that prevent some populations from getting the injections. One of these is the need to keep the vaccines in cold storage. Another is that it can be difficult for people in many parts of the world to get to a place that can administer the shots.
The researchers developing the patch say they hope the method will one day help solve these issues and increase vaccine access to millions more people around the world. And because of how the patch works, a smaller amount of vaccine can be used.
Shaomin Tian is a researcher in the Department of Microbiology and Immunology in the UNC School of Medicine. She helped lead the study. She said in a statement that the team was able to overcome manufacturing difficulties that have hurt efforts in the past to create an effective patch vaccine that uses micro-needles.
Tian said one problem with past methods was a reduction in needle sharpness from repeated manufacturing using patch molds.
But the researchers' new method permitted them to directly 3D print the patches. "Which gives us lots of design latitude for making the best micro-needles from a performance and cost point-of-view," Tian said.
The team says it is continuing to work on developing ways to include current COVID-19 vaccines - such as those from Pfizer and Moderna - for use in micro-needle patches for future testing. The method could be used for other disease vaccines as well.
Other research has been done on the use of vaccine patches. Last year, scientists from the University of Pittsburgh announced they had developed a COVID-19 vaccine that could be delivered into the skin through a patch of 400 micro-needles.
And in Australia, researchers from the University of Queensland reported in June they had created a vaccine patch that demonstrated "extremely clear" results in tests on mice. The scientists said the patches produced "much stronger and more protective immune responses against COVID-19" than traditional vaccine delivery methods.
I'm Bryan Lynn.
Bryan Lynn wrote this story for VOA Learning English, based on reports from the University of North Carolina at Chapel Hill, Stanford University, University of Queensland, University of Pittsburgh and Proceedings of the National Academy of Sciences. Susan Shand was the editor.
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Words in This Story
patch – n. a small piece of material that is worn on the skin and contains a substance that enters the body through the skin
needle – n. a think, sharp, metal part of a piece of medical equipment used to take blood out of the body or put medicine in
immune – adj. if you are immune to a disease, you will not get it
response – n. a reaction to something
advantage – n. something (such as a good position or condition) that helps to make someone or something better or more likely to succeed than others
access – n. a way of getting near, at, or to something or someone
mold – n. a container that is used to make something in a particular shape
latitude – n. freedom to do what you want
deliver – v. transport something from one place to another