Microneedle patch for flu vaccination effective in first human trial
Intradermal influenza vaccination with a dissolvable microneedle patch was well tolerated with robust antibody responses, as well as being preferred over conventional vaccination with needles and syringes, according to the first-in-human TIV-MNP 2015* study.
The patch contains microneedles ─ micron-scale solid conical structures ─ which dissolve after application to the skin, thereby delivering vaccine into the skin while leaving behind a patch that can be disposed of as nonsharps waste.
“Having the option of a flu vaccine that can be easily and painlessly self-administered could increase coverage and protection by this important vaccine [besides reducing immunization cost],” said lead author and principal investigator Dr Nadine Rouphael of Emory University School of Medicine in Atlanta, Georgia, US.
The partly blinded phase I study randomized 100 adults (aged 18–49 years), who were naïve to the influenza vaccine for the 2014-2015 season, to any one of the four groups: single-dose inactivated influenza vaccine delivered (i) by microneedle patch, or (ii) by intramuscular injection, or (iii) placebo by microneedle patch, or (iv) self-administered vaccination using microneedle patch [groups (i) to (iii) were administered by healthcare workers]. The inactivated vaccine comprised surface antigens from the H1N1 (18 µg), H3N2 (17 µg), and B strains (15 µg). [Lancet 2017;doi:10.1016/S0140-6736(17)30575-5]
No incidence was reported for the primary safety outcomes of treatment-related serious adverse events (AEs) within 180 days and treatment-related unsolicited grade ≥3 AEs within 28 days after administration. There was also no report of new-onset chronic illnesses by 180 days, the secondary safety outcome.
Within 8 days of vaccination, local and systemic reactions to vaccination were mostly mild and transient, with tenderness (60 percent) and pain (44 percent) being commonly associated with the intramuscular route, whereas tenderness (66 percent), erythema (40 percent), and itch (82 percent) were commonly reported after vaccination by microneedle patch.
Compared with intramuscular injection, vaccination through microneedle patch by healthcare workers showed comparable levels of functional antibody induction, as reflected by similar geometric mean titres at day 28 for all strains of influenza vaccine (p=0.5 for H1N1, p=0.4 for H3N2, and p=0.06 for the B strain).
Similarly, participants who self-vaccinated through the microneedle patch achieved geometric mean titres comparable to that administered by healthcare workers (p>0.05 for all strains), implying that the patch was easy to use for the general public.
“Self-immunization by microneedle patch was achieved in all participants with only brief training with audiovisual materials and without healthcare worker intervention,” said Rouphael and co-authors.
A significantly higher percentage of seroconversion was observed at 28 days after vaccination with microneedle patch vs placebo (p<0.0001).
Among the participants receiving microneedle patch (through healthcare workers or self-administered), more participants reported at 28 days after vaccination that they would prefer vaccination through microneedle patch (70 percent) over intramuscular or intranasal routes (19 percent) for future immunization (p<0.001), indicating a positive experience with the patch.
“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,” wrote Drs Katja Höschler and Maria Zambon from the National Infections Service at Public Health England in London, UK, in an accompanying commentary. [Lancet 2017;doi:10.1016/S0140-6736(17)31364-8]