Newborns get their very first shot within 24 hours of birth. That first vaccine protects against hepatitis B, and it’s given before you leave the hospital. From there, the next round of vaccines happens at the 2-month well-child visit, which is when the schedule picks up significantly. Here’s what to expect at each stage during your baby’s first six months.
The First Shot: Before You Leave the Hospital
The hepatitis B vaccine is the only shot given at birth. The CDC recommends it for all infants regardless of whether the birth parent has a hepatitis B infection. For babies born to a parent who does have the virus (or whose status is unknown), the vaccine is given within 12 hours of delivery. For babies born to a parent who tests negative, it’s given within the first 24 hours.
The reason this one can’t wait is practical: hepatitis B spreads through blood and body fluids, and an infant exposed during birth can develop a chronic, lifelong infection. The vaccine given early acts as a safety net, especially since not every infection in a birth parent is caught before delivery. Babies who weigh less than about 4.4 pounds at birth follow a slightly different timing protocol, but they still receive the vaccine on the same day.
The 2-Month Visit: When Things Ramp Up
The 2-month checkup is the biggest vaccine appointment in your baby’s first year. At this visit, your baby is scheduled to receive protection against several diseases at once:
- DTaP: diphtheria, tetanus, and whooping cough (pertussis)
- Hib: a bacterial infection that can cause meningitis
- PCV: pneumococcal disease, another cause of meningitis and pneumonia
- IPV: polio
- Rotavirus: a common cause of severe diarrhea in infants (given as oral drops, not a shot)
- Hepatitis B: second dose
That list looks long, but combination vaccines reduce the number of actual injections. A single shot called Vaxelis, for example, covers six diseases in one: diphtheria, tetanus, pertussis, polio, hepatitis B, and Hib. Another combination called Pediarix covers five. So instead of five or six separate needles, your baby may only get two or three shots plus the oral rotavirus drops.
Your baby may also receive a dose of a preventive antibody for RSV (respiratory syncytial virus) depending on whether you received an RSV vaccine during pregnancy. This isn’t technically a vaccine but a protective antibody given as an injection.
Why Vaccines Start at 2 Months
Newborns borrow immune protection from their mother during pregnancy. These maternal antibodies circulate in the baby’s blood and offer a temporary shield against infections the mother has fought off. But they also interfere with how a baby responds to vaccines. When maternal antibodies are present, they latch onto vaccine components and signal the baby’s immune cells that there’s no threat to respond to, essentially blocking the baby from building its own immunity.
By 2 months, maternal antibody levels have dropped enough that the baby’s immune system can mount a real response to vaccines. This is also why certain vaccines, like measles, mumps, and rubella, aren’t given until 12 months. The maternal antibodies against those specific viruses tend to stick around longer. The timing of each vaccine in the schedule reflects this balance between fading borrowed protection and the baby’s ability to build its own.
The 4-Month and 6-Month Visits
At 4 months, your baby receives second doses of most of the same vaccines from the 2-month visit: DTaP, Hib, pneumococcal, polio, and rotavirus. These aren’t repeats for the sake of repetition. Young immune systems need multiple exposures to build strong, lasting protection. Each dose trains the immune system to recognize the pathogen faster and produce a stronger response.
At 6 months, the schedule includes third doses of DTaP, pneumococcal, and the final dose of hepatitis B (which can be given anytime between 6 and 18 months). The third dose of polio is also due, though it has a wider window. If it’s flu season, your baby becomes eligible for an influenza vaccine starting at 6 months as well. Babies getting the flu shot for the first time need two doses spaced four weeks apart.
What Side Effects to Expect
The most common reactions are mild: soreness or slight swelling at the injection site, a low-grade fever, fussiness, tiredness, decreased appetite, and occasionally vomiting. These typically show up within hours of the shots and resolve within a day or two. A fever after vaccination is a sign the immune system is responding, not a sign something has gone wrong.
Serious reactions are rare. After a DTaP shot, for instance, non-stop crying lasting three hours or more, or a fever above 105°F, can happen but are uncommon. If your baby seems otherwise alert, is feeding, and improves within 48 hours, the reaction is almost certainly normal.
How to Comfort Your Baby During Shots
Breastfeeding during or immediately before the injection is one of the most effective ways to reduce your baby’s pain. A study of 150 infants found that babies who breastfed during vaccination had significantly lower pain scores than those given sugar water or music therapy. Breast milk triggers the release of natural pain-relieving compounds, and the combination of skin contact, sucking, and sweet taste works together to dampen pain signals.
If breastfeeding isn’t an option, holding your baby skin-to-skin, offering a pacifier, or having the provider place a small amount of sugar water on the baby’s tongue before the shot can also help. Keeping your baby in your lap rather than laying them flat on an exam table makes a difference too. Babies who feel secure and close to a caregiver consistently show less distress.
Premature Babies Follow the Same Timeline
If your baby was born early, vaccines are still given based on chronological age, meaning the time since birth, not the adjusted age based on your due date. A baby born at 32 weeks who is now 2 months old gets vaccinated at 2 months, even if they’re still in the hospital. Children’s Hospital of Philadelphia confirms that preterm infants should receive their 2-month vaccines at the standard chronological age and continue on the regular schedule from there.
The one exception is the birth dose of hepatitis B for very small babies (under about 4.4 pounds). These infants still get the shot at birth, but the dose may not count toward their series total because their immune response at that size can be weaker. Their pediatrician will add an extra dose to make up for it.