Scientists at King's College London say they have demonstrated the ability to deliver a dried live vaccine to the skin without using a traditional needle. They also state that this technique is powerful enough to enable specialized immune cells in the skin to kick-start the immunizing properties of the vaccine.

Funded by the Bill & Melinda Gates Foundation, the researchers say that, although it is an early study, this technical advance offers a potential solution to the challenges of delivering live vaccines in resource-limited countries globally, without the need for refrigeration.

As a cheaper alternative to hypodermic needles, it would also remove safety risks from needle contamination and the pain-free administration could lead to more people taking up a vaccination. In addition, they say that it could have an impact beyond infectious disease vaccination programs, for example, managing autoimmune and inflammatory conditions such as diabetes.

Although promising research is underway to develop vaccines for HIV, malaria, and TB, in countries where transporting and storing live vaccines in a continuously cold environment would not be possible, any live vaccines could become unsafe and lose effectiveness.

The team at King's used a silicone mold to create an array of micro-needles made of sugar that dissolve when inserted into the skin. Using a dried version of a live modified adenovirus-based candidate HIV vaccine in sugar, they discovered that the dried live vaccine remained stable and effective at room temperature.

The study is part of a larger project funded by the Bill & Melinda Gates Foundation linking other groups, including those at Imperial College London and Royal Holloway University of London, who are working on other aspects of HIV vaccination.