Babies receive roughly 24 to 28 individual vaccine doses by their first birthday, depending on the specific brands your pediatrician uses. That number sounds like a lot, but it covers protection against 14 serious diseases and is spread across just six or seven office visits. Here’s what the 2025 CDC schedule looks like, broken down by age.
What Happens at Each Visit
The vaccine schedule follows a predictable rhythm. Your baby gets one shot at birth, then the busiest appointments cluster at 2, 4, and 6 months, with another important round at 12 months. Each visit builds on the last, adding doses to strengthen your baby’s immune response over time.
Birth: Hepatitis B, 1st dose. This is the only vaccine given in the hospital, typically within 24 hours. It protects against a liver infection that can spread through household contact, even when no family member is known to carry the virus.
1 month: Hepatitis B, 2nd dose (sometimes delayed to 2 months).
2 months: This is the first big appointment, with up to six vaccines: rotavirus (oral drops, not an injection), DTaP (diphtheria, tetanus, and whooping cough), Hib (a type of bacterial meningitis), pneumococcal, polio, and hepatitis B if the second dose wasn’t given at 1 month.
4 months: The same core group returns for second doses: rotavirus, DTaP, Hib, pneumococcal, and polio. Five vaccines total.
6 months: Third doses of DTaP, Hib, pneumococcal, polio, and hepatitis B. Depending on the rotavirus brand, a third dose of that goes here too. Babies also become eligible for their first flu shot at 6 months, and if it’s their first flu season, they need two doses spaced four weeks apart.
12 months: Three new vaccines appear for the first time: MMR (measles, mumps, rubella), chickenpox, and hepatitis A. Booster doses of Hib and pneumococcal round out the visit.
How Many Actual Shots Per Visit
The number of doses and the number of needle sticks aren’t the same thing. Combination vaccines bundle multiple vaccines into a single injection. One widely used combination called Vaxelis combines DTaP, hepatitis B, Hib, and polio into one shot. When your pediatrician uses it at the 2-, 4-, and 6-month visits, it replaces four separate injections with one.
With combination vaccines, a typical 2-month visit involves two or three injections plus one oral dose (rotavirus, which is given as liquid drops by mouth). The 4-month visit looks similar. Without combination vaccines, those visits could mean four separate shots plus the oral dose. Either way, the total protection is identical.
What Each Vaccine Protects Against
The first-year schedule covers protection against 14 diseases:
- Hepatitis B: a virus that causes chronic liver disease
- Rotavirus: the leading cause of severe diarrhea and dehydration in infants
- Diphtheria: a bacterial infection that can block the airway
- Tetanus: causes severe muscle spasms from bacteria in soil and wounds
- Pertussis (whooping cough): a highly contagious cough that can be life-threatening for babies
- Hib disease: a bacterial infection that can cause meningitis and pneumonia
- Pneumococcal disease: another cause of meningitis, blood infections, and ear infections
- Polio: a virus that can cause permanent paralysis
- Influenza (flu): seasonal respiratory virus, vaccine-eligible starting at 6 months
- Measles: highly contagious virus that can cause brain swelling
- Mumps: causes painful swelling of the salivary glands
- Rubella: typically mild but devastating to unborn babies if a pregnant person is infected
- Chickenpox: causes itchy blisters and can lead to serious skin infections or pneumonia
- Hepatitis A: a virus that causes liver inflammation, first dose given at 12 months
The RSV Shot
A newer addition to the infant schedule is an RSV (respiratory syncytial virus) antibody, typically given as a single injection. It’s not a traditional vaccine. Instead, it delivers ready-made antibodies that protect babies during RSV season, which runs roughly October through March in most of the U.S.
Not every baby needs it. If the birth parent received an RSV vaccine during pregnancy at least 14 days before delivery, the baby generally has enough protection already. For babies whose mothers weren’t vaccinated or whose vaccination status is unknown, the shot is recommended before 8 months of age. Babies born during RSV season should ideally get it within the first week of life, during their birth hospitalization.
Why So Many Doses of the Same Vaccine
Most infant vaccines require three or four doses to build full immunity. A baby’s immune system is learning from scratch, and each dose teaches it to recognize a specific germ more effectively. The first dose primes the response. The second and third doses strengthen it and make protection last longer. Skipping or delaying doses leaves gaps where a baby is only partially protected.
The spacing between doses matters too. The intervals (typically two months apart for the core series) give the immune system time to process each dose and build a stronger response to the next one. That’s why the schedule clusters vaccines at 2, 4, and 6 months rather than giving them all at once or spreading them out over years.
Rotavirus Is Different
Rotavirus is the one vaccine that isn’t a shot. It’s given as oral drops, which makes it painless for the baby. Depending on the brand, infants get either two doses (at 2 and 4 months) or three doses (at 2, 4, and 6 months). There’s a strict timing window: the first dose must be given before 15 weeks of age, and all doses need to be completed before 8 months. If your baby misses that window, the series can’t be started or finished late.
The 12-Month Visit Adds New Vaccines
The 12-month appointment introduces vaccines that weren’t possible earlier. MMR and chickenpox vaccines use weakened live viruses, and a baby’s immune system needs to be mature enough to respond to them effectively. That’s why these vaccines don’t appear until the first birthday.
Hepatitis A also starts at 12 months, given as a two-dose series with the second dose at least six months later. At this same visit, your baby gets booster doses of Hib and pneumococcal vaccines to cement the protection built during the earlier series. All told, the 12-month appointment typically involves four to five vaccines, some of which can be combined into fewer injections depending on what your pediatrician stocks.
Putting the Numbers in Context
Twenty-four to 28 doses across the first year breaks down to about three to six vaccines per visit, with only six or seven visits total. Many of those visits overlap with routine well-child checkups your baby would have anyway. The busiest stretch is 2 through 6 months, when the core series is building. After that, the pace slows, with the 12-month visit serving as a milestone for new vaccines and final boosters in the infant series.
The schedule continues after the first birthday, with additional boosters of DTaP, polio, and other vaccines between 15 months and 6 years. But the heaviest concentration of new vaccines falls squarely in that first year, when babies are most vulnerable to the diseases the shots prevent.