Health Information Library

By Mayo Clinic Staff

Caring for a new baby comes with countless decisions. Deciding when or whether to vaccinate your baby can feel especially big.

Routine childhood vaccines have prevented hundreds of millions of illnesses and hospitalizations. They've also dramatically reduced deaths from diseases that used to be common in infants and young children.

Still, for many new parents, vaccines can bring up questions and worries. Here are some of the most common ones.

Babies are born with an immune system that's still developing. For a short time after birth, they carry some protective antibodies they received from the mother during pregnancy. But this early protection fades quickly.

Vaccines are timed for the exact moment a child's immune system is ready to learn, and before dangerous infections have a chance to reach the child.

For example, in the U.S., hepatitis B vaccination is recommended at birth. That's because birthing parents can pass on the disease when the baby is born. Sometimes the parents might not even know they're carrying the virus.

On the other hand, the measles vaccine is typically given at 12 to 15 months. That's because younger babies still have protection from their mothers, assuming the mother was vaccinated or had the disease at some point. This protection can make the vaccine less effective if it's given to the baby earlier.

Yes. Vaccines are tested more rigorously than almost any other medical product.

Before a vaccine ever reaches a clinic, it goes through years of careful testing with thousands of volunteers. Researchers start with adults, then expand to larger and younger groups. A vaccine is approved only if its benefits clearly outweigh any risks.

Even after vaccines are in use, scientists continue studying them in millions of people to make sure they stay safe and effective over time.

Plus, babies' immune systems are incredibly capable. Every day, your baby's immune system responds to thousands of new particles, from food proteins and harmless bacteria to pet dander. Vaccines are a minor event when compared with these daily exposures.

For almost all babies and children, the benefits of getting a vaccine are much greater than the risk of possible side effects.

Serious side effects from a vaccine are very unlikely. Most reactions, if they happen at all, are mild and temporary, like a sore leg or low fever.

Plus, vaccine safety continues to be monitored, even after the vaccines are widely used. Experts are prepared to act quickly if any rare safety problems arise.

It can be hard to watch your baby get even one shot. But getting several vaccines at once is safe and recommended for several reasons:

• Getting vaccines together does not overload a baby's immune system. Children's bodies handle far more every single day just by being alive in the world.
• Spacing them out increases a child's risk. Delaying vaccines creates a longer window where a child is not protected against infections.
• Combination or same-day vaccines often mean fewer needle pokes overall. Fewer shots can equal less stress and discomfort for the baby and fewer appointments to manage for you. It also can lower the cost of providing this care.

There are a few situations where your healthcare team may suggest a different combination. For example, the care team may separate measles-mumps-rubella and chickenpox vaccines for certain young toddlers. These are decisions you can talk about together based on your child's specific needs.

If you're not sure about vaccines, bring a question to your next healthcare visit: "Can you walk me through what shots my baby is getting today and why these vaccines are recommended now?"

This question can open a conversation to help you understand why some vaccines are recommended early in life. You don't have to make decisions alone. Your child's care team wants to support you, not pressure you.

Another small, helpful action you can take now: Add your baby's vaccine schedule to your phone calendar. You'll get reminders, just like you would for any other important appointment. This can help you keep your baby's protection on track.

With the right information and support, these decisions don't have to feel overwhelming. Vaccinating children early is one of the best ways to protect their health. The science and decades of real-world use all show the same result: Vaccines are safe, and they work.