The development of microarray patches for vaccine application has the potential to revolutionise vaccine delivery. Microarray patches (MAP) reduce risks of needle stick injury, do not require reconstitution and have the potential to enhance immune responses using a fractional vaccine dose. To date, the majority of research has focused on vaccine delivery with little characterisation of local skin response and recovery. Here we study in detail the immediate local skin response and recovery of the skin post high density MAP application in 12 individuals receiving 3 MAPs randomly assigned to the forearm and upper arm. Responses were characterised by clinical scoring, dermatoscopy, evaporimetry and tissue viability imaging (TiVi). MAP application resulted in punctures in the epidermis, a significant transepidermal water loss (TEWL), the peak TEWL being concomitant with peak erythema responses visualised by TiVi. TEWL and TiVi responses reduced over time, with TEWL returning to baseline by 48 h and erythema fading over the course of a 7 day period. As MAPs for vaccination move into larger clinical studies more variation of individual subject phenotypic or disease propensity will be encountered which will require consideration both in regard to reliability of dose delivery and degree of inherent skin response.

Background: Swedish Emergency Departments (EDs) see 2.6 million visits annually. Sweden has a strong tradition of health care databases, but information on patients’ pathways to the ED is not documented in any registry. The aim of this study was to provide a national overview of pathways, degree of medical acuteness according to triage, chief complaints, and hospital admission rates for adult patients (≥18 years) visiting Swedish EDs during 24 h. Methods: A national cross-sectional study including all patients at 43 of Sweden’s 72 EDs during 24 h on April 25th, 2018. Pathway to the ED, medical acuteness at triage, admission and basic demographics were registered by dedicated assessors present at every ED for the duration of the study. Descriptive data are reported. Results: A total of 3875 adult patients (median age 59; range 18 to 107; 50% men) were included in the study. Complete data for pathway to the ED was reported for 3693 patients (98%). The most common pathway was self-referred walk-in (n = 1310; 34%), followed by ambulance (n = 920; 24%), referral from a general practitioner (n = 497; 1 3%), and telephone referral by the national medical helpline “1177” (n = 409; 10%). In patients 18 to 64 years, self-referred walk-in was most common, whereas transport by ambulance dominated in patients > 64 years. Of the 3365 patients who received a medical acuteness level at triage, 4% were classified as Red (Immediate), 18% as Orange (very urgent), 47% as Yellow (Urgent), 26% as Green (Standard), and 5% as Blue (Non-Urgent). Abdominal or chest pain were the most common chief complaints representing approximately 1/3 of all presentations. Overall, the admission rate was 27%. Arrival by ambulance was associated with the highest rate of admission (53%), whereas walk-in patients and telephone referrals were less often admitted. Conclusion: Self-referred walk-in was the overall most common pathway followed by ambulance. Patients arriving by ambulance were often elderly, critically ill and often admitted to in-patient care, whereas arrival by self-referred walk-in was more common in younger patients.