Parenting Advice From Your Physicians at Kaiser Permanente

Many parents have questions about vaccines for their children. It’s important to put your thought and care into any decision that affects your child’s health. We recommend you start by talking with their doctor. As a pediatrician, I can tell you that we really want to take the time to answer your questions. You want what’s best for your child – and so do we!

Here are some of parents’ most frequently asked questions about childhood vaccines:

Why do children need to be vaccinated?

Vaccinations protect your child from serious illnesses. They play a key role in keeping your child healthy. Young children are more susceptible to severe illness from diseases because their immune system isn’t fully developed. That’s why we give vaccines when they’re young – to protect them during their most vulnerable years. The recommended vaccine schedule is based on extensive research and is designed to provide the best protection at the right time.

Can’t I just wait to vaccinate my baby until they’re a little older and stronger?

This is your decision, and we’ll help you vaccinate your child whenever you decide to do so. However, we do have to let you know that waiting can be dangerous, because very young babies are the most at risk of harm from the serious illnesses that vaccines prevent. For example, a baby who gets influenza (flu) is more likely to need hospitalization and intensive treatment than a 5-year-old who gets it. And a baby who gets pertussis (whooping cough) is at much higher risk of developing pneumonia and serious trouble breathing, while an older child will usually just have a very prolonged cough.

Young babies are strong enough to handle vaccines – but often, they’re not strong enough to handle the diseases vaccines protect against.

Isn’t natural exposure to germs through playing with other children enough for my child to build a healthy immune system?

Being around other children does help your child’s immune system learn to handle everyday germs and fight off common viruses that typically cause mild illness. We know that young kids get lots of colds – especially if they’re in daycare, preschool or kindergarten. And each time they get a cold, they’re helping their immune system build memory that helps it fight off future colds.

When it comes to serious diseases, it’s not safe to expose your child in the same way, because they could become seriously ill in a way that threatens their life. Because it’s hard to predict who might become severely ill, we rely on vaccines to keep the littlest kids safe.

Vaccines teach your child’s immune system to recognize and fight off dangerous diseases, preventing or lowering the risk of severe complications. They provide a higher level of protection than natural exposure alone.

Are vaccines safe for my child?

Yes. Before a vaccine is approved, it goes through many rounds of rigorous testing to make sure it’s both safe and effective. Even after a vaccine is approved, health experts continue to keep a close eye on vaccine safety. Vaccines are one of the safest ways to protect your child from serious illness.

Another way to think about this is that pediatricians have had years of education and real-life experience on which to base our advice. We’ve gone to school and then worked for years, and we’ve seen many, many children get very sick. Many of us have our own children, too. In the 25 years I’ve been a pediatrician, I’ve never met a pediatrician whose children were unvaccinated. We want only the best for our kids – and that means we don’t want them to get the scary infections we’ve seen in our patients. We want to care for your children the way we care for our own.

Can vaccines cause serious side effects?

Serious side effects from vaccines are extremely rare. Most children experience only mild side effects, such as a sore arm or low-grade fever, which typically go away quickly on their own. The benefits of preventing diseases like measles, pertussis, pneumococcus and polio outweigh the very small chance of serious side effects.

What are you doing to ensure the safety of patients who experience a severe allergic reaction to a vaccine?

Although allergic reactions to childhood immunizations are rare, we’re well-prepared to handle them if they occur. Your doctor’s office has trained clinical staff, medications, and necessary equipment to quickly assess and manage any potential allergic reactions.

Are vaccines such as those for the measles, mumps, and rubella (MMR) linked to childhood developmental issues such as autism?

No. The false claim that vaccines cause autism came from one small study, published originally in The Lancet in 1998 retracted in 2010. It’s been proven wrong by multiple independent research groups. This really is old fake news.

Is it true that the polio vaccine contains a virus called SV40 linked to cancer? Is the vaccine safe?

The polio vaccine used today does not contain SV40 and is made with strict regulations with advanced testing to ensure it’s safe and effective. Between 1955 and 1963, some early batches of polio vaccines were contaminated with SV40. Once this was discovered, strict safety measures were put in place, and vaccines have been carefully tested for contamination ever since. Multiple studies over decades of research have shown no evidence that the old vaccines caused cancer.

Are there additives in vaccines?

Vaccines do have additives for several purposes, including keeping the vaccine purified, stable, and sterile (free of infectious contaminants like bacteria and mold). They may also have additional ingredients that boost the body’s positive response to the vaccine. The American Academy of Pediatrics explains: “The amount of each additive used in vaccines is very, very small. In fact, we are exposed to much higher levels of these chemicals in our everyday lives.” For example, “aluminum salts are found naturally in soil, water, and foods such as soy.”

Are vaccines really effective in eradicating diseases?

Yes, vaccines have been incredibly helpful in eradicating or controlling many dangerous diseases. For example, polio has been nearly eradicated worldwide. Smallpox was completely eradicated in 1980 thanks to a global vaccination effort. Vaccines have also drastically reduced cases of measles, rubella, and hepatitis B.

In 2000, measles was declared eliminated in the United States – but unfortunately, now it is spreading again in populations where fewer people are vaccinated. This puts anyone who’s not protected at risk, including babies too young to get vaccinated.

Why are vaccines necessary if these diseases are rare now?

Diseases like tetanus, diphtheria, hemophilus, polio, and measles are rare because vaccines have been so effective. But when vaccination rates drop, we start to see diseases like these coming back. For example, when fewer people came in for routine vaccinations during the COVID-19 pandemic, measles outbreaks rose due to lower vaccination rates.

This happens in part due to something called herd immunity. Vaccines don’t offer 100% protection – while most people who get a vaccine will become immune to the disease, some will not. But if enough people in their community are vaccinated and become immune, disease spread will be limited and the non-immune person will be protected by fact that the “herd” (their community) is unlikely to get and spread the disease to them.

Is it too hard on my baby to get multiple shots at one time?

I know how hard it is to watch our babies get shots! But I find it reassuring that studies show it’s no more stressful for babies to get multiple shots than one. In fact, it seems more stressful for them to have to keep coming back to the doctor’s office to get shots one at a time on different days.

Resources for Parents

American Academy of Pediatrics

Vaccine Preventable Diseases