Children’s Vaccines: The Basics

Medically Reviewed by Melinda Ratini, MS, DO on March 04, 2024
6 min read

Being a parent means you likely worry about keeping your child safe and healthy. You treat bumps and bruises, and soothe them when they're sick. Routine wellness visits that include vaccines are another important way to protect your child's health.

Learn why doctors recommend certain vaccines and when your child should get them. Below are answers to some common questions you might have.

It's an injectable or oral medicine that protects you against a serious or deadly disease. A vaccine helps your immune system build the tools, called antibodies, it needs to fight viruses and bacteria that cause illnesses. It can take a few weeks for the body to make those antibodies. So if you're exposed to the disease right before or right after getting the vaccine for it, you could still get sick. 

Almost all healthy kids should get vaccines as they grow up. Your child’s doctor can help you know when it’s time for vaccinations.  You can also find out more about the vaccination schedule from the CDC.

Here are the shots doctors recommend for most kids:

Birth Through 6 Years

  • Hepatitis B (hep B) - This prevents an infection that causes liver failure. Children need three doses in their first 18 months of life.
  • Respiratory syncytial virus (RSV): -Either mother or infant should be immunized with nirsevimab (RSV monoclonal antibody) to prevent respiratory syncytial virus lower respiratory tract infection in infants.  
  • Rotavirus (RV) – This protects your child from a stomach infection that causes life-threatening diarrhea. Babies get 2 or 3 oral doses between ages 2-6 months (depending on the vaccine brand).
  • Diphtheria, tetanus, and pertussis (DTaP) – Five doses protect against all three diseases. They start at 2 months through age 6.
  • Haemophilus influenza type b (Hib) - The vaccine protects against a bacteria that causes dangerous brain, lung, and windpipe infections. Kids get it three or four times (depending on the vaccine brand) starting at 2 months.
  • Pneumococcal vaccine (PCV15, PCV 20; 2 years PPSV23) – It comes in four doses, starting at 2 months. The shot protects against deadly brain and blood infections.
  • Inactivated poliovirus vaccine (IPV) – Four doses protect against polio. They start at 2 months.
  • Measles, mumps, rubella (MMR) – Two doses guard against all three of these illnesses. Your child gets one at 12-15 months and another at 4-6 years.
  • Hepatitis A (hep A) - The hep A virus can cause liver failure. Children should get 2 doses of the vaccine starting at age 1.
  • Varicella (chickenpox) - Kids need two doses, spaced out about 4-5 years. The first is usually given with the MMR at 12-15  months. The second is usually given at 4  to 6 years of age.
  • Influenza (flu) - The CDC recommends that everyone age 6 months of age and older get this vaccine every year before the start of flu season. Kids under age 9 may need more than one dose.
  • COVID-19 (1vCOV-mRNA, 1vCOV-aPS). The CDC recommends that all children ages 6 months and up get the COVID vaccine. Anywhere from one to three doses may be needed depending on the age of the child and which vaccine is available.
  • Tetanus, diphtheria, and pertussis (Tdap) - This is a follow-up shot to the DTaP vaccine kids get when they’re younger. They need it because the protection from DTaP fades over time.
  • Meningococcal conjugate vaccine (MenACWY-TT/MenB-FHbp, Penbraya) – These protect against four types of meningococcal bacteria that cause meningitis, a disease that affects the brain and spinal cord.  Kids need their first dose at age 11 or 12 and a booster dose at age 16.
  • Meningococcal b vaccine -- The MenB shot protects against a fifth type of meningococcal bacterium (called type B). It is fairly new and is recommended for 16 years and older who are at increased risk for meningococcal disease.
  • Human papillomavirus (HPV) – This common virus is linked to cervical cancer as well as cancers of the back of the throat, anus, penis, vagina, or vulva and genital warts. Children need 2 doses if the series is started at age 11 - 14, and 3 doses if it is started after 15 years of age.
  • Influenza (Flu) – Recommended every year.
  • COVID vaccine - one or two doses of vaccine are recommended depending on the vaccine used and the age of the child or teen.

Your child will also need these shots if they didn’t get them before age 7:

  • Hep A
  • Hep B
  • IPV
  • MMR
  • Varicella

Scientists base the timing of vaccines for children on a few things:

  1. The age when a vaccine works best in the immune system. Researchers have carefully studied the right age and dosage for each one -- and the timing of boosters.
  2. It’s important to prevent illness as early as possible. Spacing out shots means your child goes longer without protection. The diseases that vaccines prevent are often more serious for babies and young children than they are for adults.

You might wonder if it’s OK to space out your child’s shots. But keep in mind that there’s lots of evidence that the vaccine schedule recommended by the CDC is the best for children. And there’s no evidence that any other schedule is safer or works better.

A child's body fights off up to 6,000 germs every day. The total amount that a standard round of vaccines exposes them to is only 150. 

Some vaccines need more than one dose to help the immune system build up enough tools to protect the body. It’s important to get all the doses in a vaccine series. If you don't, your child isn’t getting full protection.

Other vaccines wear off over time. "Booster" shots make sure the immune system can still fight a disease.

If your child misses a dose, talk to their doctor to get it rescheduled.The CDC has a “Catch-Up Immunization Schedule” for people who miss shots.

If your child has a cold, it’s usually OK for them to get their shots on time. But if they're very ill, the doctor may want to wait a while. Make sure the doctor knows if your child is or has been sick before they get a vaccine. 

People with certain cancers and immune system problems should not get vaccines made with live viruses. These include the nasal spray flu vaccine (FluMist), chickenpox (varicella), and MMR.  Be sure your child’s doctor knows about all their health conditions.

If your child has had a severe allergic reaction to a vaccine in the past, they shouldn’t get that shot again. They may also need to skip a vaccine if they have a severe allergy to:

  • Eggs
  • Some types of antibiotics
  • Gelatin

The doctor can tell you whether or not a vaccine is right for your child.

Vaccines, like any medicine, can cause side effects.

Most reactions are mild and don’t last very long. Your child may:

  • Be fussy
  • Feel sore or have red skin where they got the shot
  • Have a mild fever

Some kids also get swollen lymph nodes and joint pain. This type of reaction usually goes away without treatment. But make sure you call the doctor if it happens.

 Serious problems from vaccines are rare. Call your child’s doctor right away if you notice the following after a vaccination:

  • A lot of swelling where they got the shot
  • Rash
  • High fever

Your child will be at risk for many serious or deadly diseases. If they get sick, they can spread the germs to babies who have not yet been vaccinated or to others who cannot get a vaccine. 

Remember, your pediatrician wants to make sure your child is safe and healthy. If you have concerns, ask about them. Together you can decide what's best for your child.