No More Needles: Delivering Vaccines By Ultrasound

Good news for those afraid of needles is on the way: a new ultrasound may deliver vaccines through the skin without damaging it.

A quarter of adults and two-thirds of children are afraid of needles, according to the U.S. Centers for Disease Control and Prevention. The fear may be so strong that it can prevent people from receiving life-saving medical care, such as vaccinations.

In a 2021 survey of Americans who have not yet received the COVID-19 vaccine, 52% reported moderate to severe fear of needles.

The new method developed by the University of Oxford uses ultrasound to "push" vaccines into the skin. It relies on cavitation, an acoustic effect, which is the formation and popping of bubbles in response to a sound wave.

"We aim to harness the concentrated bursts of mechanical energy produced by these bubble collapses in three main ways. First, to clear passages through the outer layer of dead skin cells and allow vaccine molecules to pass through. Second, to act as a pump that drives the drug molecules into these passages. Lastly, to open up the membranes surrounding the cells themselves, since some types of vaccine must get inside a cell to function," Darcy Dunn-Lawless, a doctoral student at the University of Oxford's Institute of Biomedical Engineering, said in a statement.

Although initial in vivo tests showed the cavitation approach delivering 700 times fewer vaccine molecules than conventional injection, it produced a stronger immune response. This may be because the ultrasonic delivery targets the immune-rich skin rather than the muscles.

The new method could make vaccines more effective, reduce the risk of side effects, and lower costs. Dunn-Lawless says the main potential side effect is tissue damage if too much energy is applied to the body.

Exposure to excessive cavitation can cause mechanical damage to cells and structures. However, there is good evidence that such damage can be avoided by limiting exposure, so a key part of my research is to try and fully identify where this safety threshold lies for vaccine delivery.

Darcy Dunn-Lawless

Overcoming the fear of needles

It may take years until the ultrasound vaccine delivery becomes widely available. Meanwhile, the following techniques can help manage the phobia when having an injection or blood test:

• Try to relax. The more relaxed you are, the less you will notice the needle. Breathe deeply and slowly, or try counting your breaths.
• Talk it through. Let the person who is giving you a jab or taking the blood know if you are feeling nervous. They will answer your questions and distract you from the process by talking to you. Let them know if you're feeling faint.
• Distract yourself by focusing on a positive memory or an object in the room. You can also listen to music through headphones or do whatever works to distract you.
• Think positively about the reason why this is happening — the vaccine may protect you from a virus, or the blood test is necessary to look after your health. Remember that the discomfort will be quick and temporary.

Vaccines are crucial to prevent multiple diseases. Therefore, new methods of delivery are needed to address vaccine hesitancy due to the fear of needles.