By KidsDirect Editorial Team
Vaccinations during those early years are one of the most reliable ways to protect your baby from serious illness. The American Academy of Pediatrics, the American Academy of Family Physicians, and the CDC’s Advisory Committee on Immunization Practices all recommend a series of vaccines during the first two years. That list has actually grown since your own parents were filling out shot records. Below is a plain language walk through of what each one covers. This is about baby vaccines.
For the full current schedule with exact ages, our vaccine timeline lays it out visit by visit. Our guide on how vaccines work is a good place to start if you want the science behind any of this.
Hepatitis B Vaccine
Hepatitis B is a liver infection caused by a virus, and it can lead to lasting liver damage. A baby can pick it up from their mother if she’s infected before or during pregnancy. When a mom tests positive for Hepatitis B, or her status isn’t known, the baby usually gets the first dose right in the hospital. That happens right after birth. Otherwise, it’s given within the first two months. Two more doses follow over the next several months, wrapping up the series by around 18 months.
Read more in our full guide to the Hepatitis B vaccine.
DTaP Vaccine (Diphtheria, Tetanus, and Pertussis)
This one combination shot protects against three separate diseases.
- Diphtheria is caused by bacteria that produce toxins affecting the nervous system and heart, and it can lead to heart failure or paralysis in severe cases.
- Tetanus comes from bacteria that grow in wounds and release a toxin that causes painful muscle spasms, often starting in the jaw. It’s sometimes still called lockjaw.
- Pertussis, better known as whooping cough, is especially dangerous for babies under a year old and brings on a harsh, exhausting cough that can last for weeks.
DTaP became the standard version of this vaccine because it’s gentler on babies. It replaced an older whole cell formula that caused more reactions. The full series runs five doses, at 2 months, 4 months, 6 months, around 15 to 18 months, and again before kindergarten between ages 4 and 6. A booster called Tdap follows around age 11 or 12. That renews protection against all three diseases, pertussis included.
Vaccines in babies sometimes create mild reactions are common. Usually that means a slight fever under 102 degrees, some fussiness, or redness where the shot was given. These typically fade within a couple of days. Your pediatrician may suggest a dose of acetaminophen if your baby seems uncomfortable.
Each piece of this combination shot has its own guide too, covering diphtheria, tetanus, and pertussis in more depth.
Hib Vaccine (Haemophilus Influenza Type B)
Despite the name, this isn’t the flu. Hib is a fast moving bacterial infection that can cause ear infections and bronchitis. In kids under two, it can also lead to meningitis, a serious infection of the tissue around the brain and spinal cord. Most infants get three doses during their first year, at 2, 4, and 6 months. A booster follows between 12 and 15 months.
Our guide on the Hib vaccine goes into more detail on what it protects against.
Polio Vaccine
Polio is a serious viral disease that starts with fever and can progress to paralysis, muscle wasting, and permanent disability. In its worst form, it can be fatal. The vaccine used in the US today is IPV, given by injection. It replaced the older oral version since it carries no risk of causing the disease itself. The standard schedule runs at 2 months, 4 months, sometime between 6 and 18 months, and again between 4 and 6 years.
See our full guide on the polio vaccine for more on how it works.
MMR Vaccine (Measles, Mumps, and Rubella)
One shot here covers three separate viral illnesses.
- Measles causes a distinctive red rash along with cold like symptoms and a high fever.
- Mumps leads to swelling in the glands near the ears and jaw, often along with fever and pain while chewing.
- Rubella, sometimes called German measles, brings on a milder rash along with fever and swollen glands.
The first MMR dose is usually given between 12 and 15 months, and serious side effects are rare. Some babies get a bit sleepier than usual, or develop a mild rash, a slight fever, or some swelling in the neck or diaper area. The second dose comes later. It’s given between ages 4 and 6.
Our full guide to the MMR vaccine covers each of these three diseases in more depth.
Varicella Vaccine (Chickenpox)
This one protects against chickenpox, a highly contagious virus that causes an itchy, blister like rash. It’s given in two doses rather than one. The first comes between 12 and 15 months, and the second between ages 4 and 6, similar timing to the MMR schedule.
Read more in our guide to the chickenpox vaccine.
This gives you the shape of the first two years, but it’s not the whole picture. Vaccines against pneumococcal disease, rotavirus, hepatitis A, RSV, and the annual flu shot have all become part of routine care since this list was first put together. You can see exactly when each one is recommended on our full vaccine timeline. Your pediatrician is always the best source for what’s right for your child specifically.
Some of the background here was first published in Vaccinating Your Child, an early 2000s parenting book by pediatrician Dr. Sharon G. Humiston and journalist Cynthia Good, and has been updated with current CDC guidance.
