The chickenpox vaccine is not a particularly strong reaction, and it is not normally reactive; some people may have reactions of varying degrees.
The varicella vaccine itself does not necessarily cause a strong reaction in the vaccinated population, it is the part of the population that, for their own reasons, may have a more intense reaction after vaccination. Normally, if there is no allergy to the components of the vaccine, no adverse reaction will occur.
If there is allergy to some components of the vaccine, localized redness, swelling and hard nodules may occur in mild cases, and in severe cases, anaphylaxis and other severe reactions may result. There is no fixed probability, nor is it a certain outcome, depending on the vaccinee’s own history of allergy, physical condition and other factors, so no generalization can be made, and it is recommended to consult a doctor.