Which of the following symptoms may appear 6-12 hours post-influenza vaccination?

Following an influenza vaccination, it is common for individuals to experience localized and systemic reactions as part of the body’s immune response to the vaccine. Symptoms such as malaise and chills may typically present anywhere from 6 to 12 hours post-vaccination.

Malaise refers to a general feeling of discomfort or unease and is a well-documented systemic response as the immune system begins to recognize the antigens in the vaccine and mobilizes to mount a defense. Chills can occur as part of this immune response as well, often linked to the body's process of regulating temperature in response to immune activation.

Together, the presence of malaise and chills post-vaccination reflects the body’s typical physiological response to vaccination rather than an indication of illness. Understanding these symptoms is essential for healthcare providers to reassure patients that these effects are common and represent the development of immunity rather than a negative reaction to the vaccine.