Local Response and Barrier Recovery in Elderly Skin Following the Application of High-Density Microarray Patches

Abstract

The high-density microneedle array patch (HD-MAP) is a promising alternative vaccine delivery system device with broad application in disease, including SARS-CoV-2. Skin reactivity to HD-MAP applications has been extensively studied in young individuals, but not in the >65 years population, a risk group often requiring higher dose vaccines to produce protective immune responses. The primary aims of the present study were to characterise local inflammatory responses and barrier recovery to HD-MAPs in elderly skin. In twelve volunteers aged 69–84 years, HD-MAPs were applied to the forearm and deltoid regions. Measurements of transepidermal water loss (TEWL), dielectric permittivity and erythema were performed before and after HD-MAP application at t = 10 min, 30 min, 48 h, and 7 days. At all sites, TEWL (barrier damage), dielectric permittivity (superficial water);, and erythema measurements rapidly increased after HD-MAP application. After 7 days, the mean measures had recovered toward pre-application values. The fact that the degree and chronology of skin reactivity and recovery after HD-MAP was similar in elderly skin to that previously reported in younger adults suggests that the reactivity basis for physical immune enhancement observed in younger adults will also be achievable in the older population.

Immunogenicity, safety, usability and acceptability of microarray patches for vaccination: a systematic review and meta-analysis

“…Pigmentation was noted in three clinical studies,7 14 16 which lasted a maximum of 189 days in JEV MAPs 7. Two studies reported wet bleeding, typically resolving quickly within 30 min 39 40. Oedema was reported in two studies and resolved by day 8 40 41.…”

“…One RCT was only partly blinded when comparing MAP to N&S, but did not blind active and placebo MAPs 12. Loss to follow-up in four longitudinal studies was not reported or could not be determined 15 38–40…”

“…Findings on the safety of MAPs are summarised in online supplemental appendix S5. Two-thirds of papers (n=14, 66.6%) reported on the safety of MAPs, with no serious treatment-related AEs 7 8 11–16 37–41 43. Serious AEs assessed as unrelated to treatment were reported among four participants in two RCTs 12 13.…”

“…Oedema was reported in two studies and resolved by day 8 40 41. Less frequent AEs included exfoliation,15 39 swelling,43 myalgia,11 lymphadenopathy,11 fever,14 petechiae39 40 and black dots 39…”

“…A total of 12 studies reported pain scores following the use of MAPs,7 8 11–16 37–39 43 and seven compared pain scores with N&S7 8 11–14 37 using similar visual analogue scales. Li and colleagues and one study by Hirobe and colleagues did not report the scale used to measure pain 14 37.…”