It's hard to separate facts from misinformation. Get the answers parents like you are searching for.
It can be confusing to know what vaccine information is true and what is not. And that can lead to more questions than answers. We’re here to help you do your own vaccine homework and vaccinate with confidence by providing you with clear, honest, accurate answers to your questions. You’ll also find links to other sources that have additional credible information.
Featured Questions
How do I know vaccines are safe for my child?
Learn more: How do I know vaccines are safe for my child?How do we know vaccines work?
Learn more: How do we know vaccines work?How do I know if my child is up to date on routine vaccines?
Learn more: How do I know if my child is up to date on routine vaccines?
Vaccines and immunity basics
Vaccines help protect your child against diseases that can cause severe illness and even death. Missing or delaying vaccines puts your child at risk for illnesses you can prevent.
Since routine vaccination began, the number of children who get sick or die from diseases that vaccines prevent has greatly decreased. Vaccines are so successful that some diseases are rarely seen in the United States anymore. Without vaccines, diseases that are rare can—and do—come back.
No. Clean water, modern sanitation, and good hygiene practices like handwashing can slow the spread of and prevent infectious diseases. But immunization provides your body protective antibodies which can fight off diseases. Good hygiene cannot do that.
Children can develop immunity after they recover from an infectious disease. This is called natural immunity. However, no one can predict whether a child will get seriously ill from the disease or have long-term effects after getting sick. Vaccines provide a safe way to build immunity against diseases without the risks that come with getting the actual disease.
Germs can travel quickly from person to person. And germs that cause infectious diseases can make people very sick. Vaccines help protect people from getting diseases. Community immunity (also called “herd immunity”) happens when enough people in a community have immunity to a particular disease either through vaccination or prior infection. It makes it much harder for that disease to spread.
Some diseases that vaccines can prevent may not seem that dangerous. And since most parents in the United States keep their kids up to date on routine vaccines, serious cases of vaccine-preventable diseases are much rarer than they used to be.
Vaccines are the reason many diseases are rare in the United States. If we stop vaccinating, these diseases will come back. Many countries have not yet had the success the United States has had with vaccinating its children, so these diseases are still common in many parts of the world. When unvaccinated people travel, diseases often travel with them.
Timing my child’s vaccination
Sticking to the vaccine schedule helps protect your child against more than a dozen diseases by the time they turn 2 years old, and even more during their teen years.
Vaccinating your child on time is the best way to protect them against vaccine-preventable diseases.
You can find out if your child is up to date on their routine vaccines by contacting your child’s doctor or the last place your child received a vaccination, your state's immunization registry, or your child’s school.
Yes. Getting multiple recommended vaccines at once is safe for your child. Additionally, combination vaccines have been shown to be safe and effective. Infants’ and children’s immune systems are used to being busy.
Vaccine safety
Vaccines are some of the most studied medical interventions in the world. The United States has many requirements that make sure vaccines are safe, effective, and high quality. Among these are extensive testing before approval and rigorous safety monitoring after approval.
Vaccines go through many steps before being made available to the public. There are three important things to know about new vaccines: Vaccine science builds on decades of research; vaccine clinical trials and several other systems monitor for any long-term side effects; and misinformation about new vaccines is very common.
The most common side effects of vaccines are pain, swelling, or redness where the shot was given; mild fever; chills; feeling tired; headache; and muscle or joint aches. These side effects can be a sign that your child’s immune system is working with the vaccine. They are temporary and should go away within a few days.
Because vaccines are given to millions of babies, children, teenagers, and adults, it’s important that vaccines are shown to be safe and effective. Prior to approval, as part of the U.S. Food and Drug Administration’s (FDA) evaluation, FDA takes all of the ingredients of a vaccine into account.
Vaccines work well, but some children who are vaccinated still get sick. Getting vaccinated helps protect children from both mild and serious illnesses that could lead to hospital care or even death.
The Vaccine Adverse Event Reporting System, or VAERS, is a vaccine safety monitoring system and part of the national vaccine safety net. VAERS accepts and analyzes reports of possible health problems that people have after they get vaccinated. Anyone can submit a report to VAERS, and VAERS reports are available to the public. The Centers for Diseases Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA) use VAERS to help identify potential safety problems with vaccines.
Sometimes, vaccines can cause routine, mild side effects that go away in a few days, such as a low fever. Not everyone will get side effects. Side effects can be a sign that the immune system is working with the vaccine to create protection against disease.
When vaccines are studied in clinical trials, they are studied to make sure they are safe and work to prevent or reduce disease. They are also studied to find out the right dose. The goal is to find the dose that provides a strong immune response with the fewest number of side effects.
An adverse event is an undesirable effect that happens after vaccines. Adverse reactions can be common or rare. They can also be mild or serious.
Vaccines save lives by preventing disease. But in rare cases, a vaccine may cause an injury. The National Vaccine Injury Compensation Program (VICP) may provide compensation to people found to be injured by certain vaccines.
Preparing for vaccination appointments
Your child can get vaccinated at a well-child visit, a vaccine appointment, or a sick visit. In all of these appointments, there are ways to help make getting your child vaccinated easier.
There are a few ways to help you and your child feel comfortable and confident during vaccination appointments. You can ask for a numbing ointment or spray to reduce pain, provide comfort after the shot, and plan an activity afterward.
Children with a mild illness or low fever can still get vaccines. A mild illness does not affect how well the body responds to a vaccine. And vaccines do not make a mild illness worse. Children with moderate or serious illness may need to wait until they are better to get some vaccines.
Most health insurance plans pay for or cover most of the cost for childhood vaccines. In addition, many children have vaccine coverage through Medicaid or the Children’s Health Insurance Program (CHIP). If you don’t have health insurance, your child can still get vaccinated for free or at a low cost.
If your child is afraid of vaccines, there are many ways you can make the vaccine appointment a more positive experience. Common ways to support your child if they are afraid of vaccines are talking to your child in a positive manner, reassuring them, helping them feel more comfortable, and making vaccination a positive experience by doing something they love afterwards.
Vaccine-preventable diseases
There are many risks that come with vaccine-preventable diseases, but vaccination has proven to be the safest way to protect your child against serious illness.source: 1
Quiz: How well do you know the risks?
Question 1 of 5: How many childhood deaths have routine vaccines prevented?
Correct
Very good!
Incorrect
No, vaccines have saved many more children!
Vaccines are expected to prevent more than 1 million deaths among children in the United States who were born between 1994 and 2023. That’s more than the entire population of Denver, Colorado.
Question 2 of 5: What diseases have vaccines wiped from the face of the earth?
Correct
Yes! Before a vaccine was used to eradicate smallpox, 3 out of 10 people who had it died.
Incorrect
Good try, but only smallpox has been wiped from the face of the earth. Before a vaccine was used to eradicate smallpox, 3 out of 10 people who had it died.
But we are also very close to eradicating polio. Polio paralyzed almost 21,000 people in the U.S. in 1952 alone. Polio is rare in the United States, but it still exists in a few countries in Asia and Africa. Remember, we still need to vaccinate until polio is gone everywhere, because viruses, just like people, travel.
Question 3 of 5: If one person has measles, how contagious is it in people who are not immune?
Correct
Correct! Measles is one of the most contagious diseases in the world. If 1 person has it, 9 out of 10 people close to that person will also get measles if they aren't protected.
Incorrect
No, measles is one of the most contagious diseases in the world. If 1 person has it, 9 out of 10 people close to that person will also get measles if they aren't protected.
Measles can live in the air for up to 2 hours after an infected person leaves an area. It can be a very serious disease:
- 1 in 5 unvaccinated people who get measles will be hospitalized
- 1 in 20 unvaccinated children who get measles will get pneumonia
- Unvaccinated pregnant women who get measles may have a premature or low birth weight baby
Question 4 of 5: Why do we still need to vaccinate for whooping cough?
Correct
Yes! All the answers are correct. Whooping cough can be very serious for babies.
Incorrect
Actually, all the answers are correct. Whooping cough can be very serious for babies.
Thanks to most kids getting whooping cough vaccines, cases of the disease have decreased more than 75%. And getting vaccinated while pregnant passes protection to the baby. This helps protect the baby before they’re old enough to get their own vaccine.
Question 5 of 5: What are the risks of serious side effects happening after vaccination?
Correct
Yes! Generally, only 1–2 vaccine doses in 1 million will result in a severe allergic reaction.
Incorrect
No, the risk is much, much smaller. Generally, only 1–2 vaccine doses in 1 million will result in a severe allergic reaction.
To put that in perspective, you have a 1 in 15,300 chance of being struck by lightning in your lifetime and a 1 in 46,744 chance of dying from a hornet, wasp, or bee sting—both much more likely than having a severe allergic reaction from a vaccine.
It’s important to understand the true risk of something to make an informed decision.
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Vaccine safety
Vaccines go through extensive testing prior to being approved and rigorous monitoring after approval to ensure they are safe for your child.source: 2,source: 3,source: 4
Vaccine science
The science behind vaccines helps us understand how they work and why they are effective.
Vaccine schedule
Sticking to the vaccine schedule helps protect your child against more than a dozen diseases by the time they turn 2 years old.source: 5,source: 6