Vaccines and Flu Shots: What You Need to Know for 2025
Read this blog post in Spanish.
Getting a vaccine is quick and helps protect kids from serious illnesses.
As we approach the fall, back to school, and flu season, it is important to emphasize how crucial it is to be up to date on vaccines.
Vaccines have saved millions of lives and have helped get rid of many serious childhood illnesses. But for vaccines to work well, many people need to get them. With a lot of confusing news and information out there, I want to help clear up some common questions.
Questions and answers about vaccines
Q: How do vaccines work?
A: A vaccine helps your body recognize a virus or bacteria (germ) so that you can fight it off in the future. It helps your body make antibodies that find and destroy the germ before it makes you sick. Exposing the body to a mild virus or bacteria can provide immunity to a more deadly disease.
Q: Why are vaccines important?
A: Vaccines protect people from illnesses that can be dangerous. For people with weak immune systems, vaccines are especially important. When more people get a vaccine, it helps protect those who cannot get it.
Vaccines are safe for most everyone, including pregnant people. They help in the prevention and spread of such illnesses as flu, COVID-19, RSV, and whooping cough. Preventing illness with vaccines is much safer than getting sick with an infectious disease.
Q: Why are people hesitant about vaccines?
A: There is a lot of confusing and contradictory information being shared on websites and social media. It is sometimes hard to know what is real and what is fake. Peer groups and social circles can influence how people feel about vaccines. I urge you to follow your health care team’s advice about vaccines and which ones you and your child need.
Q: What can happen if you or your child do not get a vaccine?
A: Not getting important vaccines can lead to getting very sick and possibly hospitalized. You also put others at risk, such as young children, older people, and people with weak immune systems. If not enough people are vaccinated against infectious illnesses, it can lead to dangerous outbreaks.
Q: Can you get sick from getting a vaccine?
A: A vaccine’s benefits in preventing illness are much greater than the small risks. Common side effects from vaccines include a sore arm, mild rash, or fever. But getting an infectious illness can be serious and lead to severe health problems.
Q: What is a vaccine schedule and why do I have to follow it?
A: Health experts from the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) put a lot of time, thought, and research into the vaccine schedule for children in the United States. It is a set of recommended ages and times to get vaccines for diseases like measles, polio, whooping cough, hepatitis, and HPV. The timing is based on children’s immune system development and when exposure to diseases is most likely.
The vaccine schedule has been proven safe and effective. Not following the vaccine schedule can make you more likely to get sick and to miss important vaccines you need.
Q: What are the side effects of vaccines?
A: The most common vaccine side effects are redness and swelling where you got the shot; fever; or soreness. Any signs of illness are signs that the body is preparing to fight off the germ or illness.
Q: What is herd immunity, and how can it protect those who cannot get vaccinated?
A: Herd immunity is the term for when enough people are immune to a disease (through being vaccinated or having had the disease) that the illness does not spread easily. Herd immunity protects everyone, including those with weak immune systems and those who cannot get vaccinated. To reach herd immunity for measles, for example, around 95% of the population would need to be vaccinated.
Q: Do vaccines cause autism?
A: Studies have shown no link between vaccines and autism. Health care providers diagnose autism based on a child’s health history and behavior. Autism spectrum disorder is often first noticed in children between 18 and 30 months old, around the time children get some vaccines. This can make it seem like there is a connection—but there is not. Autism starts before a baby is born, even though symptoms may not appear until later.
Ask your child’s care team if your child is up to date on all their required vaccines. Make sure to get any vaccines that you child is behind on. Vaccines are especially important for children with serious illness. If your child is going through treatment for serious illness, their care team may recommend changes to their vaccine schedule. Let’s protect ourselves and everyone around us by taking care of vaccinations today.
Getting the vaccine is a quick and easy process. Help prevent the flu by getting your flu shot.
Questions and answers about the flu and flu vaccines
Getting the flu vaccine each year helps your immune system recognize and fight off the flu virus. It updates your immune system. I believe in the flu vaccine so strongly that my own children get a yearly flu vaccine, and I get one too.
As a health care professional at St. Jude Children’s Research Hospital, I know how serious it can be to get sick from the flu, measles, or other highly contagious illnesses. For children with weak immune systems who are in treatment for cancer or other serious health conditions, we want to protect them from problems caused from an infectious illness that could have been prevented.
Last flu season (2024–25), there were 231 flu-related deaths in children in the U.S., according to the CDC. Most of these children did not get the flu vaccine.
Getting vaccinated protects the people around you. This includes those who are more at risk of getting a serious case of the flu, like children with cancer, blood disorders, and other serious illnesses.
Q: Can the flu be dangerous?
A: Yes. People who are more likely to have serious problems and be hospitalized from the flu include those who:
- Are age 5 and under
- Are age 65 and older
- Have chronic health conditions such as lung disease or heart problems
- Are obese
- Are pregnant
- Have weak immune systems
Q: What are health problems that might happen from having the flu?
A: The flu could lead to pneumonia, bronchitis, sinus infections, and ear infections. These can be even more severe if you have medical conditions like heart disease, cancer, a blood disorder, or diabetes.
Q: Are flu shots still necessary? Do I need to get the flu vaccine every year?
A: Yes. The CDC recommends that everyone 6 months old and older get a flu vaccine each year. Flu viruses change all the time. This is why the flu vaccine is reviewed and updated each year; St. Jude experts are part of this review process. Therefore, a yearly vaccine is needed to give you the best protection against the flu.
Q: Can I get the flu from the flu vaccine?
A: The flu shot does not have a live virus in it and cannot give you the flu. If you feel sick after getting the vaccine, that means your body is working to develop protection and immunity, making antibodies to protect you from the flu illness.
Note: The intranasal flu vaccine (flu mist) contains live virus. People with weak immune systems should not get the flu mist vaccine.
Q: How long might I feel sick after a flu shot?
A: Symptoms like soreness, redness, mild aches, or fever may last for 1–2 days.
Q: Is there anyone who should NOT get a flu vaccine?
A: People who should not get the flu vaccine are those who:
- Are younger than 6 months old
- Have had very serious allergic reaction to a flu vaccine in the past
- Have a strong allergy to something in the vaccine
- Have had Guillain-Barré Syndrome (GBS) after a flu vaccine in the past
- Are less than 100 days after stem cell (bone marrow) transplant or cellular therapy. (Some patients who get certain types of CAR T-cell therapy may get the flu vaccine before 100 days have passed.)
Q: Will I get the flu if I get the vaccine?
A: There is a possibility that you will still get the flu, but it would be much milder than if you had not gotten the vaccine. You will have far less risk of getting very ill or being hospitalized with the flu.
Q: Can people with an egg allergy get the flu vaccine?
A: The CDC stated that beginning with the 2023–24 flu season, people with egg allergies can get the flu vaccine. They do not need to take extra safety measures, regardless of how severe their egg allergy is.
Q: When should I get my flu vaccine?
A: As soon as the vaccine comes out this year in pharmacies, workplaces, and doctor’s offices, go out and get it. It is best to get the vaccine by October, but any time you can get it will help protect you and others. Some patients with serious illness may need 2 doses of the flu vaccine given at least 28 days apart. If you have questions about the flu vaccine, ask your care team.
Q: How do I get my flu vaccine?
A: Talk to your health care team today. You can usually go to your doctor’s office, local pharmacy, health department, or urgent care center. Getting the vaccine is a quick and easy process. You will be glad you got it.
If you live in the United States, you can use this tool to find flu vaccines near you.
