A flu 'patch' that doesn't need a nurse to administer or 'cold chain' storage has been successfully trialled as an alternative to the traditional flu shot, says a study published in the Lancet today.
The dissolvable microneedle patch was found to be safe way to deliver the flu vaccine and was preferred over a conventional injection in a phase 1 trial involving 100 people.
Public health experts have said an exciting aspect of this microneedle patch was its low cost, safety and simpler storage, which could make it a good candidate for vaccination programmes in poorer countries or for people who currently avoid injections.
The study, led by Emory University and Georgia Institute of Technology in the United States, was the first randomised trial to compare a self-administered 'patch' vaccine in humans against a health professional administered patch or a conventional vaccine injection.
Tests 28 days after vaccination indicated that the microneedle patch led to a "robust immune response" similar to conventional intramuscular injection, but the research team said larger trials were needed to further investigate the immune mechanism behind the response and confirm the findings.
The patch was found to be safely administered by trial participants who were shown, via a brief video, how to apply the patch to their wrist for 20 minutes. Examination of the used patches also indicated that the microneedles had dissolved in the skin so patches potentially could be discarded as non-sharps waste eliminating the safety risks of disposing of sharps waste.
The patches were found to be stable for one year at 40 degrees Celsius, outside of the usual cold chain process, so potentially could be stored on a pharmacy shelf.
Dr Nadine Rouphael, Associate Professor of Medicine at Emory University, USA, and lead author of the study, said dissolvable microneedle patches that were stable outside of the cold chain could potentially simplify the delivery of influenza vaccines.
"The patch could also be safely applied by participants themselves, meaning we could envisage vaccination at home, in the work place, or even via mail distribution." She said this could reduce the cost of the flu vaccine and potentially increase coverage. Larger trials were now needed to confirm the findings.
Dr Katja Höschler and Dr Maria Zambon from the National Infections Service, Public Health England wrote in a linked comment to the Lancet article that the patch study suggested a promising new option for seasonal vaccination "over present commercial injected and intradermal inactivated influenza vaccines and previous microneedle patches". Particularly in low income countries where currently only about a quarter had influenza immunization policies compared to 92 per cent of high income countries.
"Microneedle patches have the potential to become ideal candidates for vaccination programmes, not only in poorly resourced settings, but also for individuals who currently prefer not to get vaccinated, potentially even being an attractive vaccine for the paediatric population, provided late-stage clinical development confirms vaccine efficacy.”
The 100 participants (aged 18-49) were randomly assigned to one of four groups: they received either a vaccine microneedle patch, vaccine injection or placebo microneedle patch administered by a health professional, or a self-applied vaccine microneedle patch. Participants received a single dose of inactivated influenza vaccine (fluvirin).
The vaccine injection was given in the arm, and the microneedle patch was applied for 20 minutes on the wrist. The trial included an "audible and tactile feedback mechanism" to tell self-administering patch participants when sufficient force was applied.
At six months, no serious side effects linked to the vaccine were reported and there were no cases of influenza in any of the groups. Minor reactions to the vaccine were mild and transient. Pain and tenderness were most commonly reported in the injection group, and redness, itching and tenderness in the vaccine microneedle patch groups.
Immediately after receiving the vaccine, participants reported high acceptability with scores of 4.5-4.8 (out of 5) in the three microneedle patch groups, similar to the injection group (4.4). At 28 days post vaccination, 70% (33/47) of participants who had received the microneedle patch vaccine said they preferred it to the injection.
Nadine G Rauphael, Michael Paine, Regina Mosel et al (2017). The safety, immunogenicity, and acceptability of inactivated influenza vaccine delivered by microneedle patch (TIV-MNP 2015): a randomised, partly blinded, placebo-controlled, phase 1 trial. The Lancet (Published online June 27 2017)