Innate local response and tissue recovery following application of high density microarray patches to human skin.

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.

Erratum: Author Correction: M-protein based vaccine induces immunogenicity and protection from Streptococcus pyogenes when delivered on a high-density microarray patch (HD-MAP).

[This corrects the article DOI: 10.1038/s41541-020-00222-2.].

M-protein based vaccine induces immunogenicity and protection from Streptococcus pyogenes when delivered on a high-density microarray patch (HD-MAP).

We evaluated vaccination against Streptococcus pyogenes with the candidate vaccine, J8-DT, delivered by a high-density microarray patch (HD-MAP). We showed that vaccination with J8-DT eluted from a coated HD-MAP (J8-DT/HD-MAP), induced similar total IgG responses to that generated by vaccination with J8-DT adjuvanted with Alum (J8-DT/Alum). We evaluated the effect of dose reduction and the number of vaccinations on the antibody response profile of vaccinated mice. A reduction in the number of vaccinations (from three to two) with J8-DT/HD-MAP induced comparable antibody responses to three vaccinations with intramuscular J8-DT/Alum. Vaccine-induced protection against an S. pyogenes skin challenge was assessed. J8-DT/HD-MAP vaccination led to a significant reduction in the number of S. pyogenes colony forming units in skin (92.9%) and blood (100%) compared to intramuscular vaccination with unadjuvanted J8-DT. The protection profile was comparable to that of intramuscular J8-DT/Alum. J8-DT/HD-MAP induced a shift in the antibody isotype profile, with a bias towards Th1-related isotypes, compared to J8-DT/Alum (Th2 bias). Based on the results of this study, the use of J8-DT/HD-MAP should be considered in future clinical development and control programs against S. pyogenes. Furthermore, the innate characteristics of the technology, such as vaccine stability and increased coverage, ease of use, reduction of sharp waste and the potential reduction of dose may be advantageous compared to current vaccination methods.

Comparison of Biological Properties of Two Medicinal Extracts of the Tehuacan-Cuicatlan Valley.

In the Valley of Tehuacan-Cuicatlan, Cyrtocarpa procera and Bursera morelensis are located and are used in traditional medicine. In this research, several biological properties were evaluated. The methanol extracts of C. procera (MeCp) and B. morelensis (MeBm) were obtained by maceration. The antibacterial activities of the extracts were evaluated by the Kirby-Baüer disc-diffusion method. The wound healing activity was evaluated by histopathological analysis. Both extracts had a bacteriostatic effect in the Staphylococcus aureus (MeCp MIC = 0.25 mg/mL and MeBm MIC = 1 mg/mL) and the Vibrio cholerae (MeCp MIC = 1 mg/mL and MeBm MIC = 4 mg/mL). Both extracts demonstrated a wound healing efficacy similar to the reference standard (Recoveron). They also showed a high antioxidant capacity (MeCp SC50 = 5.75 µg/mL and MeBm SC50 = 4.27 µg/mL). These results are related to the concentration of phenols (MeCp = 166 and MeBm = 236.6 mg GAe/g) and flavonoids of MeCp = 16 and MeBm = 22 µg Qe/g. Both extracts, acting in a similar way in microorganisms that cause infection thanks to their antioxidant activity, favor the healing of wounds. This is the first study in which the biological properties of these two species are compared.

Safety, tolerability, acceptability and immunogenicity of an influenza vaccine delivered to human skin by a novel high-density microprojection array patch (Nanopatch™).

BACKGROUND: Injection using needle and syringe (N&S) is the most widely used method for vaccination, but requires trained healthcare workers. Fear of needles, risk of needle-stick injury, and the need to reconstitute lyophilised vaccines, are also drawbacks. The Nanopatch (NP) is a microarray skin patch comprised of a high-density array of microprojections dry-coated with vaccine that is being developed to address these shortcomings. Here we report a randomised, partly-blinded, placebo-controlled trial that represents the first use in humans of the NP to deliver a vaccine. METHODS: Healthy volunteers were vaccinated once with one of the following: (1) NPs coated with split inactivated influenza virus (A/California/07/2009 [H1N1], 15 µg haemagglutinin (HA) per dose), applied to the volar forearm (NP-HA/FA), n = 15; (2) NPs coated with split inactivated influenza virus (A/California/07/2009 [H1N1], 15 µg HA per dose), applied to the upper arm (NP-HA/UA), n = 15; (3) Fluvax® 2016 containing 15 µg of the same H1N1 HA antigen injected intramuscularly (IM) into the deltoid (IM-HA/D), n = 15; (4) NPs coated with excipients only, applied to the volar forearm (NP-placebo/FA), n = 5; (5) NPs coated with excipients only applied to the upper arm (NP-placebo/UA), n = 5; or (6) Saline injected IM into the deltoid (IM-placebo/D), n = 5. Antibody responses at days 0, 7, and 21 were measured by haemagglutination inhibition (HAI) and microneutralisation (MN) assays. FINDINGS: NP vaccination was safe and acceptable; all adverse events were mild or moderate. Most subjects (55%) receiving patch vaccinations (HA or placebo) preferred the NP compared with their past experience of IM injection with N&S (preferred by 24%). The antigen-vaccinated groups had statistically higher HAI titres at day 7 and 21 compared with baseline (p < 0.0001), with no statistical differences between the treatment groups (p > 0.05), although the group sizes were small. The geometric mean HAI titres at day 21 for the NP-HA/FA, NP-HA/UA and IM-HA/D groups were: 335 (189-593 95% CI), 160 (74-345 95% CI), and 221 (129-380 95% CI) respectively. A similar pattern of responses was seen with the MN assays. Application site reactions were mild or moderate, and more marked with the influenza vaccine NPs than with the placebo or IM injection. INTERPRETATION: Influenza vaccination using the NP appeared to be safe, and acceptable in this first time in humans study, and induced similar immune responses to vaccination by IM injection.