title: Microneedle-mediated vaccine delivery: harnessing cutaneous immunobiology to improve efficacy.
abstract: BACKGROUND
  Breaching the skin's stratum corneum barrier raises the possibility of the administration of vaccines, gene vectors, antibodies and even nanoparticles, all of which have at least their initial effect on populations of skin cells.
  
  
  METHODS
  Intradermal vaccine delivery holds enormous potential for improved therapeutic outcomes for patients, particularly those in the developing world. Various vaccine-delivery strategies have been employed, which are discussed in this review. The importance of cutaneous immunobiology on the effect produced by microneedle-mediated intradermal vaccination is also discussed.
  
  
  CONCLUSIONS
  Microneedle-mediated vaccines hold enormous potential for patient benefit. However, in order for microneedle vaccine strategies to fulfill their potential, the proportion of an immune response that is due to the local action of delivered vaccines on skin antigen-presenting cells, and what is due to a systemic effect from vaccines reaching the systemic circulation, must be determined. Moreover, industry will need to invest significantly in new equipment and instrumentation in order to mass-produce microneedle vaccines consistently. Finally, microneedles will need to demonstrate consistent dose delivery across patient groups and match this to reliable immune responses before they will replace tried-and-tested needle-and-syringe-based approaches.
authors.affiliation: School of Pharmacy, University Belfast, Belfast, UK.
authors.forename: Sharifa
authors.initials: S
authors.lastname: Al-Zahrani
authors.forename: Marija
authors.initials: M
authors.lastname: Zaric
authors.forename: Cian
authors.initials: C
authors.lastname: McCrudden
authors.forename: Chris
authors.initials: C
authors.lastname: Scott
authors.forename: Adrien
authors.initials: A
authors.lastname: Kissenpfennig
authors.forename: Ryan F
authors.initials: RF
authors.lastname: Donnelly
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D003713:Dendritic Cells / Q000145:classification / Q000276:immunology; D004337:Drug Carriers / Q000008:administration & dosage; D004867:Equipment Design; D006801:Humans; D007271:Injections, Intradermal / Q000295:instrumentation*; D053758:Nanoparticles / Q000008:administration & dosage; D009339:Needles; D010641:Phenotype; D012867:Skin / Q000276:immunology*; D014611:Vaccination / Q000295:instrumentation*; D014612:Vaccines / Q000008:administration & dosage*
chemical_list: D004337:Drug Carriers; D014612:Vaccines