Antigen-coated microneedle patches applied to the skin may represent a more effective way of delivering influenza vaccines than conventional techniques, a mouse study published in Scientific Reports suggests. The microneedle delivery method was shown to improve the immune response of the mice and the duration of protective immunity, although further research is needed to establish whether similar results are found in humans.
Many current influenza vaccines target the deltoid muscles of the shoulder but a more promising target may be the skin, which contains a large network of antigen presenting cells. These cells help to initiate adaptive immune responses by activating T and B cells. Previous research has indicated that the transdermal delivery of an inactivated influenza virus with microneedle patches can improve immune response.
Ioanna Skountzou, Dimitrios Koutsonanos and colleagues used a microneedle patch to deliver a single dose of a licensed influenza subunit vaccine to mice. They show that the technique confers improved and longer-lasting protection against the virus, compared with the conventional intramuscular delivery method. The results suggest that microneedle patches have the potential to be used with currently approved vaccines and, if supported by future clinical trials, may eventually be beneficial in increasing vaccine coverage and protection.