title: High frequency ultrasound to assess skin thickness in healthy adults.
abstract: Intradermal immunization is gaining increased attention due to multiple factors: (1) intradermal (ID) vaccination has been shown to induce improved immunogenicity compared to intramuscular (IM) vaccination; (2) ID vaccination has been shown to have a dose-sparing potential over IM leading to a reduced vaccine cost and an increased availability of vaccines worldwide. However, the currently used Mantoux technique for ID injection is difficult to standardize and requires training. The aim of the study was (1) to assess the epidermal and dermal thickness at the proximal ventral and dorsal forearm (PVF & PDF) and deltoid in adults aged 18-65years (2) to determine the maximum penetration depth and needle characteristics for the development of a platform of medical devices suited for intradermal injection, VAX-ID™.
  
  
  
  Mean thickness of the PVF, PDF and deltoid were measured using high-frequency ultrasound of healthy adults aged 18-65years. Correlation with gender, age and BMI was assessed using Mann-Whitney U Test, Spearman correlation and Wilcoxon Signed Ranks Test, respectively.
  
  
  
  Results showed an overall mean skin thickness of 1.19mm (0.65-1.55mm) at the PVF, 1.44mm (0.78-1.84mm) at the PDF, and 2.12mm (1,16-3.19mm) at the deltoid. Thickness of PVF & PDF and deltoid were significantly different for men vs women (pmean<0.001, <0.001, <0.001, and pmin<0.001, 0.012, <0.001, respectively). A significant association was found for age at the deltoid region (p<0.001). Skin thickness for PVF, PDF & deltoid was significantly associated to BMI (p<0.001).
  
  
  
  Significant differences in skin thickness were seen for the PVF, PDF and deltoid region for gender, and BMI. Age only influenced the skin thickness at deltoid region. A needle length of 1.0mm is best option for intradermal injection at the dorsal forearm (NCT02363465).
authors: Novosanis, Bijkhoevelaan 32c, BE-2110 Wijnegem, Belgium; Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk, Belgium. Electronic address: timothi.vanmulder@uantwerpen.be.
authors: T J S
authors: TJ
authors: Van Mulder
authors: Novosanis, Bijkhoevelaan 32c, BE-2110 Wijnegem, Belgium.
authors: M
authors: M
authors: de Koeijer
authors: Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk, Belgium.
authors: H
authors: H
authors: Theeten
authors: Novosanis, Bijkhoevelaan 32c, BE-2110 Wijnegem, Belgium.
authors: D
authors: D
authors: Willems
authors: Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk, Belgium.
authors: P
authors: P
authors: Van Damme
authors: Department of Pharmaceutical Sciences, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk, Belgium.
authors: M
authors: M
authors: Demolder
authors: Department of Pharmaceutical Sciences, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk, Belgium.
authors: G
authors: G
authors: De Meyer
authors: Novosanis, Bijkhoevelaan 32c, BE-2110 Wijnegem, Belgium; Voxdale, Bijkhoevelaan 32c, BE-2110 Wijnegem, Belgium.
authors: K C L
authors: KC
authors: Beyers
authors: Novosanis, Bijkhoevelaan 32c, BE-2110 Wijnegem, Belgium; Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk, Belgium.
authors: V
authors: V
authors: Vankerckhoven
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001837:Body Weights and Measures / Q000379:methods; D020405:Dermis / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D004817:Epidermis / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007271:Injections, Intradermal / Q000379:methods / Q000592:standards; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*; D014611:Vaccination / Q000379:methods / Q000592:standards; D055815:Young Adult
keywords: Injection device; Intradermal; Skin thickness; Vaccine delivery