Natural Products as Possible Vaccine Adjuvants for Infectious Diseases and Cancer

The first vaccine was discovered for the prevention of smallpox in 1796, from where the vaccine for rabies followed in 1885. Vaccines are used to improve the immunity of an infected individual but have a very low immunogenicity and no effective responses have been found for severe infections and cancer. Adjuvants were developed to circumvent this problem by increasing the effect of the vaccine by steering the immune system into a desired direction, thus creating an immune response that includes both innate and adaptive immunity. Natural products have been used throughout the centuries for many illnesses such as colds and flu but also for many serious conditions such as liver diseases and cancer. These medicines are known to produce their effects through an immunomodulatory response. Numerous benefits have been attributed for the use of medicinal plants for immunomodulation instead of synthetically produced immunotherapeutics. Many natural products with known immunostimulatory properties have the potential to target certain responses required for the effective control of infections, chronic diseases and cancer. By combining vaccines with an adjuvant, it may be possible to increase the low immunogenicity and the overall effectiveness of the vaccine by providing a stable, targeted and prolonged immune response, needed for the effective treatment and prevention of cancer and infectious diseases. Natural products have the potential in providing the properties for the making of an effective vaccine adjuvant.