Childhood Vaccines Explained

Vaccines are one of the most effective tools we have to keep children healthy. This page explains in plain language how vaccines work, what to expect at a shot visit, how to comfort your child and how to handle common side effects. For the current schedule and our practice's vaccine policy, see our immunizations page.

How Vaccines Work

A vaccine teaches the immune system to recognize a specific germ without your child having to get sick first. Vaccines contain a weakened or inactivated germ, or just a piece of it, or instructions for making a harmless piece. The body responds by making antibodies and memory cells. If your child is exposed to the real disease later, the immune system is ready to fight it off quickly.

Some vaccines need several doses to build strong protection, and some need boosters later in childhood as protection fades. That's why the schedule includes repeat visits. The influenza vaccine is given every year because flu viruses change.

Diseases Vaccines Help Prevent

The American Academy of Pediatrics' 2026 schedule recommends protection against 18 diseases, including measles, mumps, rubella, chickenpox, whooping cough (pertussis), diphtheria, tetanus, polio, hepatitis A and B, Haemophilus influenzae type b (Hib), pneumococcal disease, rotavirus, influenza, meningococcal disease, HPV, RSV and COVID-19. Many of these illnesses can cause pneumonia, brain swelling, hearing loss, paralysis or death, especially in babies.

Before the Visit

• Bring your child's immunization record to every visit.
• Read the Vaccine Information Statement (VIS) for each vaccine; we will provide them, and they are also available on the CDC website.
• Tell us if your child has had a serious reaction to a vaccine before, has a severe allergy, or has a condition or medicine that weakens the immune system.
• Talk honestly with older children: shots pinch for a moment, and it's okay to feel nervous.

Comforting Your Child During Shots

• Babies: hold your baby close, breastfeed or offer a bottle or pacifier during and right after the shots, and swaddle or cuddle afterward.
• Toddlers and preschoolers: sit your child on your lap in a hugging hold, bring a favorite toy or book, and use distraction like singing or blowing bubbles.
• School-age children and teens: encourage slow, deep breaths, let them look away, and praise them afterward. Teens who tend to faint should sit or lie down for a few minutes.

After the Visit: Common Side Effects

Most side effects are mild and go away within a day or two:

• Redness, swelling or soreness where the shot was given
• Low-grade fever
• Fussiness, sleepiness or decreased appetite

A cool, damp cloth on the injection site, extra fluids and cuddles help. Ask us before giving fever or pain medicine, and use the correct dose for your child's weight. Rarely, a child can have a serious allergic reaction, which usually happens within minutes; this is why we ask you to stay briefly after vaccines.

Keeping Records

Keep a copy of your child's immunization record in a safe place. You will need it for child care, school, camp, college and travel. Maryland's immunization registry, ImmuNet, also stores vaccine records given by participating providers. Ask us if you need a copy for school.

Common Myths

• "Vaccines cause autism." Decades of research involving millions of children have found no link between vaccines and autism.
• "Too many shots overwhelm the immune system." Children's immune systems handle countless germs every day. Getting several vaccines at once is safe.
• "These diseases are gone." Many still circulate. Measles outbreaks have grown in recent years where vaccination rates have dropped.

Have questions? We are always glad to talk about vaccines. Read more in our articles on the importance of immunizations and whooping cough.