Medicines and vaccinations have revolutionized illness prevention and treatment. Medicinal products may have side effects in addition to their advantages, some of which may be unwanted and/or unexpected. The research and activities relating to the identification, assessment, understanding, and prevention of adverse effects or any other medicine/vaccine-related concern are referred to as pharmacovigilance. Before being approved for use, all medications and vaccines must pass stringent safety and efficacy tests in clinical trials. The clinical trial method, on the other hand, entails testing these products on a small number of people over a short period of time. Certain negative effects may only become apparent after these products have been used by a diverse population, including persons with various disorders, for an extended period of time.