Vaccine contains active components, adjuvants, stabilizers, preservatives, and trace components. Adverse reactions to vaccines are rarely reported. However, all of vaccine components may elicit adverse reaction including life-threatening event in susceptible individuals, therefore raising concerns regarding safety of vaccine still continue up to date. Hypersensitivity reaction to vaccines can be classified as allergic reaction to the vaccine component, pseudo-allergic reaction, and exacerbation of allergic diseases. Hypersensitivity reactions to vaccine components rarely occurred in the population-level, while severe hypersensitivity reaction such as anaphylaxis may be consequent result in susceptible individuals. Some of components such as ovalbumin, gelatin, yeast, and latex were considered as common causes of allergic reactions to the vaccine. However, the incidence or causes of vaccine related hypersensitivity reaction in Korea were not well known. The aims of this article are to review the literatures with hypersensitivity reactions related with vaccine components, to provide detailed information about major components of vaccines commonly used in Korea, and to provide the best way of vaccination in susceptible individuals.