A baby’s immune system is still growing after birth. During the first two to three months of life, it gets much better at fighting germs, especially viruses. This means that a 2-week-old baby cannot fight off viruses and bacteria as well as a 3-month-old baby can.

The good news is that babies receive some protection from their mothers. Before birth, mothers pass antibodies to their babies through the placenta. These antibodies help protect babies during the first few weeks of life. Breastfeeding can also provide extra protection and support a baby’s developing immune system.

So, you might wonder: if a newborn’s immune system is still developing, why do babies get vaccines so early?

To be protected from certain diseases, babies need to build their own immunity. Even though a newborn’s immune system is not fully mature, it can still respond to vaccines. Early vaccines, such as the hepatitis B vaccine, help a baby’s immune system start learning how to fight harmful germs. This early protection is often enough to help keep babies safe from serious illnesses.

References:  Development of the Immune System | Children’s Hospital of Philadelphia, Is Your Newborn Baby’s Immune System Strong Enough?

Many diseases still occur at low levels in the United States (like mumps and hib). Some diseases that were at low levels, like measles, are starting to spread and are becoming more common again. Many other diseases are widespread in other parts of the world (like polio, rubella and diphtheria) and therefore are just a plane ride away for your family! That is why it is important to protect children with vaccines when they are young. Vaccines are your best defense from serious diseases. Learn more about these diseases by visiting the TAPI webpage – Vaccine Preventable Diseases – Arizona Partnership for Immunization.

Vaccines, including the MMR vaccine, do not cause autism. We realize that some parents have questions about vaccines and want to understand more before they decide to vaccinate their child. They may worry about the MMR vaccine, thimerosal (a preservative that was used in some vaccines in the past), or whether babies get too many vaccines at a young age. Scientists have carefully studied these concerns and have found that vaccines do not cause autism.

If you have more questions or concerns about vaccines, we encourage you to talk to your health care provider. You can also visit SARRC Discussing Vaccines and Autism – Southwest Autism Research & Resource Center (SARRC) and CHOP Vaccine and Autism: What You Should Know Q&A | Children’s Hospital of Philadelphia to read more  about the research around vaccines.

References: Vaccine and Autism: What You Should Know Q&A | Children’s Hospital of Philadelphia, Discussing Vaccines and Autism – Southwest Autism Research & Resource Center (SARRC)

The American Academy of Pediatrics (AAP) vaccine schedule is the best and most trusted schedule for children. It helps protect your child from diseases at the right time, when they need protection the most. If you have questions about vaccines, talk with your child’s doctor or health care provider. They can answer your questions and help you make the best choices for your child’s health.

References and resources: TAPI Child-Schedule.pdf and American Academy of Pediatrics (AAP)  Immunizations – HealthyChildren.org

Your OB will talk to you about a few vaccines to make sure you and your baby on the way are protected. Vaccines are recommended during pregnancy to protect against serious illnesses. The most common vaccines given in pregnancy include the flu, Tdap (to protect against pertussis), COVID-19, and RSV (respiratory syncytial virus). These vaccines can help keep you healthy during pregnancy and help protect your baby right after birth.

Ask your OB any questions you may have and work with them to schedule your vaccines at the right time for you and your baby!

Here is a short video that also talks about vaccines while you are pregnant ACOG Explains: Vaccines During Pregnancy | ACOG

Reference: Vaccines During Pregnancy | ACOG

Many questions about vaccines revolve around the ingredients in the vaccine vial. Learn why certain ingredients are used, the quantities present in vaccines, and the safety of vaccine ingredients at Types of Vaccine Ingredients | Children’s Hospital of Philadelphia

Below you will find some information regarding vaccine ingredients, aluminum and thimerosal:

Aluminum:  this is used in vaccines as an adjuvant. An adjuvant is an ingredient that boosts the immune response to a vaccine. Adjuvants allow for lesser quantities of the vaccine and fewer doses. The adjuvant effects of aluminum were discovered in 1926. 

The small amount of aluminum in a vaccine stays near the injection site and is released slowly over time as the vaccine is processed. This slow release is why vaccines that contain aluminum often cause soreness, pain and redness at the injection site. 

Studies have found that aluminum levels in blood do not detectably increase after receipt of vaccines. This slow release explains why.

Thimerosal: almost all childhood vaccines used in the United States do not contain thimerosal. Thimerosal is a preservative that was removed from routine childhood vaccines more than 20 years ago. Some flu vaccines used to contain small amounts of thimerosal, but thimerosal-free flu vaccines are available and are now the standard choice. Though studies have found no evidence that thimerosal in vaccines causes autism.

To learn more about vaccine ingredients visit Types of Vaccine Ingredients | Children’s Hospital of Philadelphia

Refernce: Vaccine Ingredients | Children’s Hospital of Philadelphia

Vaccines help your body learn how to fight germs that can make you sick. They do this by showing your immune system a safe piece of a virus or bacteria. This helps your body get ready to protect you in the future.

Vaccines do not cause the same serious illness that real infections can cause. Sometimes, a vaccine can make your immune system work hard enough to cause mild symptoms, such as a low fever.

Some people wonder if a vaccine is working if they do not get a fever. The answer is yes. Not everyone gets a fever after a vaccine. A vaccine can still work well even if there are no symptoms.

Refernce: Vaccine safety: Fever and vaccines | Children’s Hospital of Philadelphia

Let your child’s health care provider know that your child is not feeling well. Talk to them about getting your child’s shots at this visit. The doctor will determine if it is still okay based on your child’s symptoms and temperature. If your child needs to wait until they are feeling better, make sure you set a follow up vaccine appointment to keep your child’s shots up to date!

We understand you have questions! Getting clear answers to your questions is important.  We encourage you to talk to your pediatrician, your primary care doctor, your pharmacist or another trusted health care provider.

If you would like to look up additional information for children visit: Children’s Hospital of Philadelphia (Vaccine Education Center | Children’s Hospital of Philadelphia or Phoenix Children’s Hospital (Protecting Your Child with Vaccines | Phoenix Children’s Hospital) or Vaccine Information for adults  (Immunization Resources for Adults | Vaccine Information).

You can also watch AZ medical professionals from different areas of the state and walks of life talk about why vaccines are critical tools in their practices for building healthy families and communities.  ADHS – Healthy Horizons

Our immune system works hard every day, even when we do not notice it. Vaccines help our immune system learn how to fight diseases. When you get a vaccine, your body practices fighting a germ in a safer way. This helps your immune system remember what to do if it sees that germ again. Because vaccines do not make you sick with the disease, you get protection without having to go through the illness.

Getting sick to build natural immunity can be risky. If your child gets a vaccine-preventable disease before being vaccinated, it is hard to know how sick your child may get. They could miss school, you could miss work, and your child may need several doctor visits or to even go to the hospital.

Health care providers consistently say watching a child suffer from a vaccine preventable disease is always so difficult, because it could have been prevented. Talk to your health care provider about any vaccine questions you have and about keeping you and your child up to date on vaccines.