London: In what would be a real boon for India, scientists have found a way to vaccinate without using an injection. Scientists at King's College London have for the first time demonstrated the ability to deliver a dried live vaccine to the skin without a traditional needle, and shown that this technique is powerful enough to enable specialized immune cells in the skin to kickstart the immunizing properties of the vaccine.
This technical advance, they say offers a potential solution to the challenges of delivering live vaccines in resource-limited countries globally, including India, without the need for refrigeration. 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.
Dr Linda Klavinskis from King's College said "We have shown that it is possible to maintain the effectiveness of a live vaccine by drying it in sugar and applying it to the skin using microneedles — a potentially painless alternative to hypodermic needles. We have also uncovered the role of specific cells in the skin which act as a surveillance system, picking up the vaccine by this delivery system and kick-starting body's immune processes."
The new discovery involves a silicone mould to create a microneedle array — a tiny disc with several micro-needles made of sugar which dissolve when inserted into the skin.
The team formulated a dried version of a live modified adenovirus-based candidate HIV vaccine in sugar (sucrose) and used the mould to create the microneedle array. They found that the dried live vaccine remained stable and effective at room temperature.