Intradermal immunization has become a forefront of vaccine improvement, both scientifically and commercially. Newer technologies are being developed to address the need to reduce the dose required for vaccination and to improve the reliability and ease of injection, which have been major hurdles in expanding the number of approved vaccines using this route of administration. In this review, 7 y of clinical experience with a novel intradermal delivery device, the MicronJet600, which is a registered hollow microneedle that simplifies the delivery of liquid vaccines, are summarized. This device has demonstrated both significant dose-sparing and superior immunogenicity in various vaccine categories, as well as in diverse subject populations and age groups. These studies have shown that intradermal delivery using this device is safe, effective, and preferred by the subjects. Comparison with other intradermal devices and potential new applications for intradermal delivery that could be pursued in the future are also discussed.
Keywords: AE, adverse event; BCG, Bacillus Calmette–Guérin; BD, Becton Dickinson; CDC, Center of Disease Control; DTP, diphtheria, pertussis and tetanus; EMEA, European Medicines Agency; FDA, Food and Drug Administration; GMT, geometric mean titer; HA, hemagglutinin; HBV, hepatitis B virus; HIV, Human immunodeficiency virus; HPV, human papilloma virus; ID, intradermal; IM, Intramuscular; IPV, inactivated polio vaccine; MEMS, Micro Electro Mechanical System; Mantoux; PPD, Purified protein derivative; SAGE, Strategic Advisory Group of Experts; SQ, subcutaneous; WHO, World Health Organization; dose-sparing; icddr,b, International Center for Diarrheal Disease Research, Bangladesh; immunogenicity; influenza vaccine; intradermal; microneedles; vaccine delivery; vaccine device.