TRENDS IN VACCINE DEVELOPMENT: A REVIEW ARTICLE

A vaccine is a substance that boosts the immune system's defenses against disease. Most vaccines are given by needle injection, although some can also be taken by mouth or sprayed into the nose. The majority of vaccines have been in use for many years, and every year millions of individuals receive them safely. Every vaccine, like other pharmaceuticals, must undergo thorough and stringent testing to guarantee its safety before being included in a nation's vaccination program. The best antigen to employ to elicit an immune response must first be determined for each vaccination that is currently being developed. There are no human tests conducted during this preclinical stage. To gauge the safety and disease-prevention potential of an investigational vaccination, animals are used for the initial testing.