Which vaccine is not recommended for individuals with a history of severe allergic reactions?

The varicella vaccine is typically not recommended for individuals who have a history of severe allergic reactions, particularly to any component of the vaccine. Severe allergic reactions, such as anaphylaxis, can present serious health risks for those receiving vaccinations. The varicella vaccine contains gelatin and neomycin, both of which can trigger allergic reactions in sensitive individuals.

On the other hand, the MMR vaccine, flu vaccine, and hepatitis B vaccine are generally safe for individuals with allergic histories unless there is a proven allergy to specific components of those vaccines. The MMR vaccine is usually well tolerated, and most people can receive the flu vaccine, even if they have a history of allergies, unless they have a documented allergy to egg protein for the standard flu vaccine. Similarly, the hepatitis B vaccine is also usually safe, with low instances of allergic reactions reported. Thus, the varicella vaccine stands out as one that directly cautions against administration for individuals with severe allergies due to its specific components.