Many wonder if they can get a flu shot while experiencing cold symptoms. Annual flu vaccination helps reduce the incidence and severity of influenza, a respiratory infection caused by the influenza virus. The Centers for Disease Control and Prevention (CDC) recommends that nearly everyone 6 months and older receive a flu shot each year to protect against circulating strains.
The Rule of Thumb: Mild Cold Symptoms
Generally, having a common cold with mild symptoms does not prevent someone from receiving a flu shot. Symptoms like a runny nose, sneezing, a mild sore throat, or a slight cough without fever are typically considered mild. The immune system is capable of handling both a mild viral infection, such as a cold, and the vaccine simultaneously. Studies on other vaccines indicate that a mild illness at the time of vaccination does not significantly affect the body’s immune response to the vaccine.
Symptoms That Require Postponement
However, certain symptoms or conditions warrant postponing a flu shot. If you are experiencing a moderate to severe illness, especially one accompanied by a fever (typically over 100.4°F or 38°C for adults), it is advisable to delay vaccination. Other severe symptoms that suggest postponement include significant body aches, severe fatigue, vomiting, severe diarrhea, or difficulty keeping food down. If you are sick enough to stay home from work or school, this indicates a level of illness that suggests waiting. For children, a low-grade fever (under 101°F or 38.3°C) is generally acceptable, but higher fevers or severe symptoms should prompt a delay.
Why It’s Important to Wait
Delaying vaccination when experiencing moderate to severe illness helps ensure the body is in the best state to mount an optimal immune response to the vaccine. When the immune system is already heavily engaged in fighting off a significant infection, its resources might be divided, potentially leading to a less robust antibody production from the vaccine. Waiting can also prevent confusion between existing illness symptoms and potential vaccine side effects, such as a low-grade fever or muscle aches, which are normal signs that the immune system is responding to the vaccine. Consulting a healthcare provider when unsure is always a good step to determine if delaying the flu shot is necessary.