Getting your flu shot each year is the best way to reduce your risk of serious illness and protect the people around you. UC San Diego Health
Flu vaccines raise plenty of questions. How well does the flu shot work? Can it give you the flu? What side effects can you expect?
UC San Diego Health experts answer 11 commonly asked questions about flu shots, so you can understand the benefits of vaccination and make informed decisions about protecting your health.
1. Can the flu shot give me the flu?
No. The flu shot is made from an inactivated virus that can't cause the flu (also known as influenza). It takes about one to two weeks after vaccination for immunity to develop.
If you get sick shortly after getting vaccinated, it's likely you were exposed before your body developed protection. The flu shot can still help protect you from severe illness, hospitalization or death caused by the flu.
2. What are the common side effects of the flu shot?
While the flu shot can't give you the flu, some of the side effects may feel similar. Most side effects are mild and last a short time. Common side effects from a flu shot include muscle aches, low-grade fever and soreness, redness or swelling at the injection site.
3. Do healthy people need to get a flu shot?
Yes. The California Department of Public Health (CDPH) recommends that people ages 6 months and older get an annual flu vaccine — even if they are healthy — with rare exceptions. That's because influenza is highly contagious and can lead to serious complications, including pneumonia and hospitalization, even in otherwise healthy people.
4. Is the flu just a bad cold?
No. The flu and the common cold share some symptoms, but they are caused by different viruses. Flu symptoms are usually more severe and come on suddenly. Colds tend to be milder and rarely cause serious health problems. The flu can lead to complications, such as pneumonia, bacterial infections or hospitalization.
5. Is it safe to get the flu shot during pregnancy?
Yes. The CDPH recommends that all pregnant women get vaccinated against the flu. Expectant mothers are at higher risk for serious complications from influenza. Getting the flu shot while pregnant also helps protect your baby for several months after birth.
6. Do I need to get the flu shot every year?
Yes. Influenza viruses change frequently, and protection from vaccination decreases over time. Vaccines are reviewed and updated each year to target the virus strains expected to circulate that flu season. Annual vaccination provides the best protection against flu.
7. Does the flu vaccine really work?
Yes. Effectiveness can vary depending on your age, health and how well the vaccine matches the influenza viruses in circulation. Getting vaccinated is still the best way to reduce your risk of flu and serious complications. Even if you get sick after being vaccinated, the flu shot can reduce your risk of severe illness, hospitalization or death caused by the flu.
8. What are the best ways to prevent the flu?
The flu shot is your best defense against influenza, but you can take additional steps to stay healthy:
- Wash your hands frequently and clean frequently touched surfaces.
- Avoid close contact with people who are sick or coughing and sneezing.
- If you are sick, wear a mask to help protect others.
9. Can I get the flu from going out in cold weather without a coat or with wet hair?
No. The only way to catch the flu is by being exposed to influenza viruses. Flu season coincides with colder weather, so people mistakenly associate the flu with cold weather, even though they are not related.
The flu spreads mainly through close contact with an infected person when they cough, sneeze or talk. Sometimes, you can get the flu by touching a surface contaminated with the virus and then touching your mouth, nose or eyes.
10. Can antibiotics treat the flu?
No. Antibiotics fight bacterial infections but don't work against viral infections, like the flu. However, a flu infection can lead to bacterial infections. If your symptoms don't improve or get worse, contact your doctor.
11. Is winter or spring too late to get the flu shot?
No. While early fall — the start of the flu season — is considered a good time to get vaccinated, it's never too late.
Flu activity often peaks in winter and can last into late spring, so getting the shot later can still help protect you.
Flu Shots Available for UC San Diego Health patients
Make an appointment to receive the flu vaccine at a location near you. It’s available at UC San Diego Health primary care clinics, Express Care clinics and some pharmacies.
Flu Shots Same-Day Care
Flu Shots Same-Day Care
