Skin-Based Vaccination: A Systematic Mapping Review of the Types of Vaccines and Methods Used and Immunity and Protection Elicited in Pigs

Abstract

The advantages of skin-based vaccination include induction of strong immunity, dose-sparing, and ease of administration. Several technologies for skin-based immunisation in humans are being developed to maximise these key advantages. This route is more conventionally used in veterinary medicine. Skin-based vaccination of pigs is of high relevance due to their anatomical, physiological, and immunological similarities to humans, as well as being a source of zoonotic diseases and their livestock value. We conducted a systematic mapping review, focusing on vaccine-induced immunity and safety after the skin immunisation of pigs. Veterinary vaccines, specifically anti-viral vaccines, predominated in the literature. The safe and potent skin administration to pigs of adjuvanted vaccines, particularly emulsions, are frequently documented. Multiple methods of skin immunisation exist; however, there is a lack of consistent terminology and accurate descriptions of the route and device. Antibody responses, compared to other immune correlates, are most frequently reported. There is a lack of research on the underlying mechanisms of action and breadth of responses. Nevertheless, encouraging results, both in safety and immunogenicity, were observed after skin vaccination that were often comparable to or superior the intramuscular route. Further research in this area will underlie the development of enhanced skin vaccine strategies for pigs, other animals and humans.

Intradermal Vaccination against Influenza with a STING-Targeted Nanoparticle Combination Adjuvant Induces Superior Cross-Protective Humoral Immunity in Swine Compared with Intranasal and Intramuscular Immunization

“…The induction of robust systemic immune responses is one of the challenges of IN vaccination. Intradermal vaccination can induce a systemic as well as mucosal immune response in humans, mice, and pigs [55,56]. We showed previously that cyclic-di-AMP and its synthetic analogue ADU-S100 are effectively adsorbed to Nano-11 and that the combination of these two adjuvants has synergistic effects on the immune response, which is consistent with the fact that each component activates different complementary signaling pathways in antigen-presenting cells.…”

A Comprehensive Review of Our Understanding and Challenges of Viral Vaccines against Swine Pathogens

“…In domestic animals, intramuscular (IM) and subcutaneous (SC) routes are the most common routes of vaccine administration, while in pigs, IM route is the preferred route [ 16 , 24 , 176 ]. Recently, the traditional IM route of administration has been replaced by intradermal, intranasal, or oral routes [ 24 , 177 , 178 ]. Intradermal routes for DNA vaccines have shown promising results in the porcine industry.…”

“…Intradermal routes for DNA vaccines have shown promising results in the porcine industry. Needleless devices are available in the market, and intradermal administration by these devices has reduced pain and fear in sows [ 16 , 177 , 178 ]. Except for the oral route, all administrative routes may induce more or less stress on the pigs, leading to deterioration in the production and overall performance of the animal.…”

Current Status of Vaccines for Porcine Reproductive and Respiratory Syndrome: Interferon Response, Immunological Overview, and Future Prospects

“…This method is effective for PRRS vaccination, as the skin contains cells from both the innate and adaptive immune systems. This presence may explain why skin-based vaccination elicits stronger systemic immune responses [ 202 ]. Potent responses could enable vaccine dose-sparing, as demonstrated with influenza and rabies vaccines [ 203 , 204 ].…”