Self-administered microneedle flu vaccine patches may be well accepted

By Lorraine L. Janeczko

NEW YORK (Reuters Health) - Microneedle vaccine patches that people can administer themselves could make influenza vaccines more convenient and widely used at lower administrative cost, according to a new study.

In what the authors believe to be the first clinical study of microneedle patch usability and acceptability, users quickly learned to correctly apply the patches and increased their intent to vaccinate from 44% to 65%, they write in a February 11 online report in Vaccine.

"Microneedle patches have the potential to increase influenza vaccination coverage in the United States and reduce costs by enabling patients to self-administer the vaccines. The patch is simple to administer, generates no sharps waste, can be easily transported, including by mail, due to its small size and thermostability, and is expected to be manufactured at costs similar to pre-filled syringes," said senior author Dr. Mark Prausnitz, of the Georgia Institute of Technology in Atlanta, in an email to Reuters Health.

"Beyond influenza, many other drug and vaccine therapies do not reach patients because patients either need to visit a healthcare provider or receive training to self-inject for frequent treatments. Replacing the hypodermic needle with a microneedle patch can empower patients to self-administer otherwise-injectable therapies and, especially in developing countries, bring injectable vaccines and other medicines to hard-to-reach populations," he said.

The new technology needs to be tested in more clinical trials before it will be available for use, Dr. Prausnitz noted.

"A microneedle patch for influenza vaccination could be on the market in five years," he said.

"There is currently a drug-free microneedle patch developed by 3M that is sold for use as a skin pretreatment to increase drug absorption into the skin, especially for dermatological applications. Delivery of parathyroid hormone using microneedle patches to treat osteoporosis has advanced through phase 2 clinical trials by Zosano Pharma, and in early 2015, we will conduct a phase 1 clinical trial of the influenza vaccination," he said.

Dr. Prausnitz holds patents that have been licensed to companies developing microneedle-based products and is a founder and shareholder of companies developing these products.

To study microneedle patches among people with no previous experience using them, the authors conducted a randomized, repeated measures study with 91 healthy, non-pregnant adults who had no skin diseases, no pain perception problems, and no known allergies to compounds used in the study.

Two groups tested different insertion methods: 70 participants applied force to the patches with thumb pressure alone, and 21 used additional low-cost snap-based devices that closed shut with a clicking sound at a given force.

Both types of patches had stainless steel microneedles mounted on adhesive foam backing. Each patch contained 50 hexagonally arrayed 750-micrometer-long microneedles. No actual vaccine was involved in any part of the study. After the patches were pressed into the skin, the researchers applied dye, photographed the administration sites, and counted the insertion sites.

Without the snap-based device, the median number of insertion sites seen on the first attempt was 90%. On the second and third attempts, the number increased to 94%, a significant improvement (p=0.003) indicating a learning curve, the authors write.

With the snap-based device, the median number of insertion sites seen on the first attempt was 96% - a significant improvement over the non-snap-based method (p=0.006). Similar median numbers of 93% to 95% were seen on the second and third tries.

When a self-administered microneedle patch was offered, intent to vaccinate increased among participants from 44% to 65%. Of people intending to be vaccinated, 64% would want to vaccinate themselves.

Self-vaccination preference was significantly higher for those using the snap-based device (p=0.004). For both groups, microneedle patches were significantly less painful than intramuscular injections (p<0.002).

Among normally unvaccinated participants, 30% expressed willingness to get vaccinated if offered the microneedle patch, and all of them preferred the patch to intramuscular injection, suggesting that many people who do not normally get vaccinated could be convinced if offered a patch, the authors write.

All insertions were well tolerated with only very mild, transient erythema. One unrelated adverse event occurred and two participants withdrew due to lightheadedness.

Most influenza vaccine costs involve storage and administration. If microneedle patches can be produced at roughly the same cost as current vaccines, the authors calculated, the overall vaccine cost could be much lower.

Dr. Ajay K. Banga, from the College of Pharmacy of Mercer University in Atlanta, wrote in an email to Reuters Health, "The microneedle approach is ideal for delivery of vaccines and other potent drugs where this approach may meet an unmet therapeutic need. This paper presents important findings on microneedle patch usability and acceptability."

"Some of the challenges facing commercial development of this technology relate to sterilization of the microneedles, scale-up considerations to produce inexpensive microneedles on a large scale, clear understanding of pore closure in skin following microporation, and use of applicator for uniform creation of micropores in skin. These challenges can be met, and this is a very promising technology," Dr. Banga said. He was not involved in the study.

Dr. Conor O'Mahony, from the Tyndall National Institute of University College Cork, in Ireland, said in an email, "The results, although unsurprising, represent the first structured study of patient acceptability of microneedle-based vaccination patches, and reinforce the considerable but largely anecdotal data available to date. The study underlines the immense potential for self-administration of such devices."

"Crucially, microneedle self-administration eliminates the requirement for the presence of trained healthcare personnel, and this may have significant impacts on the costs and reach of mass vaccination programs, particularly in developing countries," he said.

SOURCE: http://bit.ly/1ie9Zta

Vaccine 2014.

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