Are there differences in immune responses following delivery of vaccines through acutely or chronically sun-exposed compared with sun-unexposed skin?

Are there differences in immune responses following delivery of vaccines through acutely or chronically sun-exposed compared with sun-unexposed skin? Immunology. 2019 Oct 08;: Authors: Hart PH, Norval M Abstract The majority of human vaccines are administered above the deltoid muscle of the arm, a site which is chronically sun-exposed in many people. It is known that exposure of the skin to the UV wavelengths in sunlight stimulates systemic immunosuppression, an outcome which is associated with reduced immunity to microbial infections in animal models. Here we consider whether immunisation of humans through a UV-irradiated skin site will lead to a less effective immune response compared with immunisation through an unexposed site. Studies showing that the efficacy of vaccination can be reduced when surrogates of increased levels of sun exposure, such as latitude of residence and season of the year, are considered. Results from a limited number of intervention experiments in humans demonstrate a similar pattern. To provide an explanation for these findings, changes in the number and functional potential of immune cells in chronically sun-exposed compared with unexposed skin are outlined. UV radiation-induced changes to skin cells are also relevant when considering skin sites for administration of immune tolerising peptides. The review provides the basis for further research into the effects of acute and chronic UV radiation exposure o...
Source: Immunology - Category: Allergy & Immunology Authors: Tags: Immunology Source Type: research