Why Vaccines Are So Important

Vaccines are one of the most powerful and thoroughly researched tools we have to prevent serious, life-threatening diseases in children.

Vaccines work by safely training your child’s immune system to recognize and fight harmful viruses and bacteria. This process builds protection before your child is ever exposed to these illnesses, without requiring them to become sick first.

Diseases like measles, meningitis, polio, and whooping cough still exist. They have not disappeared, but they have become rare in the United States largely because of widespread vaccination. However, when vaccine rates drop, these diseases return.

We are now seeing new outbreaks of measles, pertussis (whooping cough), and chickenpox in communities with low vaccination coverage. These illnesses can spread quickly and cause serious complications, especially in infants, pregnant individuals, and people with weakened immune systems.

Vaccination is not just a personal health decision. It is also a way to protect others. By vaccinating your child, you help protect your family and your community.

What do these vaccines protect against?

Vaccines protect against serious, often life-threatening illnesses that used to be common in children. Many of these diseases are still circulating today. The reason we don’t see them as often is because vaccines work.

MMR Vaccine – Protects Against Measles, Mumps, and Rubella

  • Measles: A highly contagious viral illness that causes high fever, cough, runny nose, red eyes, and a widespread rash. It can lead to pneumonia, brain inflammation (encephalitis), deafness, and death. Measles spreads through the air and can infect up to 90% of unvaccinated people nearby.

  • Mumps: Causes swelling of the salivary glands, fever, headache, and fatigue. Complications can include meningitis, hearing loss, and infertility in males.

  • Rubella (German measles): Typically mild in children, but very dangerous during pregnancy. It can cause miscarriage, stillbirth, or birth defects (congenital rubella syndrome).

IPV (Inactivated Polio Vaccine) – Protects Against Polio

  • Polio: A virus that spreads through contaminated water or food and can attack the nervous system. It can cause lifelong paralysis or difficulty breathing. Before vaccines, polio outbreaks led to widespread fear and disability.

DTaP Vaccine – Protects Against Diphtheria, Tetanus, and Pertussis (Whooping Cough)

  • Diphtheria: A bacterial infection that causes a thick coating in the throat, leading to breathing problems, heart failure, or death.

  • Tetanus (Lockjaw): Enters through wounds and causes painful muscle stiffness and spasms. It can lead to breathing difficulties, fractures, and death. It is not contagious but is deadly if untreated.

  • Pertussis (Whooping Cough): A severe, prolonged cough that can cause babies to stop breathing, turn blue, or develop pneumonia or brain damage. It is most dangerous in infants too young to be vaccinated.

Hib Vaccine – Protects Against Haemophilus influenzae type b

  • Hib Disease: Once the leading cause of bacterial meningitis in young children. It can also cause pneumonia, bloodstream infections, and permanent complications like hearing loss or developmental delays.

PCV (Pneumococcal Conjugate Vaccine) – Protects Against Pneumococcal Disease

  • Pneumococcal Infections: Can cause meningitis, blood infections, ear infections, and pneumonia. Before vaccines, pneumococcus was one of the most common causes of serious bacterial illness in young children.

Rotavirus Vaccine – Protects Against Rotavirus

  • Rotavirus: A virus that causes severe diarrhea, vomiting, fever, and dehydration in infants and toddlers. It spreads easily and often leads to emergency room visits and hospitalizations.

Hepatitis B Vaccine – Protects Against Hepatitis B

  • Hepatitis B: A virus that infects the liver. It can spread through blood, birth, or bodily fluids. In infants, it can cause lifelong liver disease, cirrhosis, or liver cancer.

Hepatitis A Vaccine – Protects Against Hepatitis A

  • Hepatitis A: A highly contagious virus that spreads through contaminated food, water, or close contact. It causes liver inflammation, fever, nausea, and fatigue, and can result in weeks of missed school and activity.

Varicella Vaccine – Protects Against Chickenpox

  • Chickenpox (Varicella): Causes an itchy rash, fever, and fatigue. Complications include skin infections, pneumonia, brain inflammation (encephalitis), and hospitalization. The virus can also re-emerge later in life as shingles.

HPV Vaccine – Protects Against Human Papillomavirus

  • HPV: A common virus that can cause cervical, throat, anal, and penile cancers, as well as genital warts. The vaccine is most effective when given before exposure (typically ages 9–12).

Meningococcal Vaccines (MenACWY and MenB) – Protect Against Meningococcal Disease

  • Meningococcal Disease: A rare but rapidly progressing bacterial infection that can cause meningitis and bloodstream infections. It can lead to death within hours or cause lifelong complications like limb loss, hearing loss, or brain damage.

Influenza Vaccine – Protects Against Seasonal Influenza (Flu)

  • Influenza: A contagious respiratory virus that causes high fever, cough, body aches, and fatigue. It can lead to pneumonia, hospitalization, or death—especially in children under five, pregnant individuals, and people with chronic conditions.

COVID-19 Vaccine – Protects Against Coronavirus (SARS-CoV-2)

  • COVID-19: Though often mild in children, COVID-19 can cause severe illness, respiratory complications, and hospitalizations. Some children develop long-term symptoms or a rare but serious inflammatory condition called MIS-C (Multisystem Inflammatory Syndrome in Children).

What to Expect After Vaccinations

Vaccines are very safe, and most children tolerate them well. However, mild and temporary side effects are common—they are a normal sign that the body is building protection.

Typical side effects may include:

  • Low-grade fever

  • Fussiness, sleepiness, or fatigue

  • Soreness, redness, or mild swelling at the injection site

  • Temporary decrease in appetite or increased need for rest

These symptoms usually begin within 24 hours of vaccination and resolve on their own within 1 to 2 days.

MMR-specific note: Some children may develop a mild rash or low-grade fever 6 to 12 days after receiving the MMR (measles, mumps, rubella) vaccine. This reaction is not contagious and is not a cause for concern. It reflects the immune system responding to the vaccine and typically resolves without treatment.

How to Support Your Child After Vaccination

  • Apply a cool compress or damp washcloth to the injection site to reduce discomfort or swelling.

  • Offer extra fluids, and encourage rest and quiet play.

  • Provide reassurance and comfort through cuddling or soothing routines.

  • Use acetaminophen (Tylenol) only if needed for significant discomfort or fever. Always follow age-appropriate dosing instructions and avoid giving medications unless the child is truly uncomfortable or inconsolable.

When to see Your Pediatrician

Most side effects are mild and self-limiting. However, you should see your pediatrician if your child experiences:

  • A fever over 104°F (40°C)

  • Persistent crying lasting more than 3 hours

  • Worsening swelling or redness at the injection site after 48 hours

  • Signs of an allergic reaction, such as:

    • Swelling of the face or lips

    • Hives or widespread rash

    • Difficulty breathing or wheezing

These serious reactions are extremely rare, but if they do occur, seek medical attention right away.

Why Am I Getting the Same Vaccine Multiple Times?

Booster Doses Are Important

Some vaccines are given in a series, either close together or spread out over years to help your child’s immune system develop strong and lasting protection.

  • The first dose introduces the immune system to the germ (bacteria or virus) in a safe and controlled way.

  • The second and third doses build on that response, increasing the number of immune cells trained to fight the infection.

  • Booster doses are given months or years later to remind the immune system and ensure long-term memory.

Think of it like learning. One lesson isn’t enough to master the material, reviewing and repeating helps you remember. The immune system works the same way.

Examples:

  • The MMR vaccine (measles, mumps, rubella) provides lifelong protection after two doses.

  • The DTaP vaccine (diphtheria, tetanus, pertussis) needs several doses and periodic boosters because immunity fades over time.

Is It Safe to Get Multiple Vaccines at Once?

Yes. Children’s immune systems handle far more daily exposure from food, play, and the environment than what vaccines provide.

Giving multiple vaccines at the same visit:

  • Offers faster protection when children need it most

  • Reduces the number of appointments, saving time and preventing missed school

  • Minimizes stress for both child and caregiver

  • Does not overload the immune system; in fact, it helps train it to be stronger and more responsive

Combination vaccines are used when available to reduce the number of shots. If preferred, vaccines can be given separately across more visits, but more visits means more pokes.

Do Vaccines Cause Autism?

No. Vaccines do not cause autism.

This misconception began with a 1998 study that falsely claimed a connection between the MMR vaccine and autism. That study was later found to be fraudulent, unethical, and scientifically invalid. It was formally retracted, and the lead author lost his medical license. Unfortunately, the fear it created continues to persist in some communities.

Since then, extensive research involving hundreds of thousands of children worldwide has found no evidence of any link between vaccines and autism. These studies span multiple countries, vaccine types, and populations, and they consistently show that vaccines are safe and do not increase autism risk.

Evidence-Based Research Confirms:

  • Taylor LE, Swerdfeger AL, Eslick GD. Vaccines are not associated with autism: A meta-analysis. Vaccine. 2014;32(29):3623–3629. doi:10.1016/j.vaccine.2014.04.085

  • Institute of Medicine. Adverse Effects of Vaccines: Evidence and Causality. National Academies Press; 2012.

  • CDC and WHO Safety Reports: Both organizations continue to monitor vaccine safety globally and have repeatedly confirmed there is no link between vaccines and autism.

If you have questions about vaccine safety, please speak with a trusted medical professional. Your child’s health and your peace of mind matter.

Evidence-Based Research Supporting Vaccines

There is overwhelming scientific consensus that vaccines are among the most thoroughly studied, safest, and most effective public health interventions ever developed. Decades of research and ongoing surveillance consistently demonstrate their ability to prevent disease, save lives, and protect entire communities.

Evidence-based research supports that:

  • Vaccination prevents 4 to 5 million deaths globally each year. This includes deaths from diseases such as measles, diphtheria, tetanus, and whooping cough. (World Health Organization. Immunization Coverage. 2023)

  • Vaccine-preventable diseases have declined by more than 90% in countries with high immunization rates. Outbreaks tend to occur in areas where vaccination coverage has decreased. (CDC Pink Book, 2023)

  • Vaccines undergo extensive clinical trials before approval and are continuously monitored for safety once in use. Vaccine safety monitoring systems track even rare side effects and ensure rapid response if concerns arise. (CDC Vaccine Safety Monitoring, 2023)

  • Serious adverse events from vaccines are extremely rare. The risk of complications from vaccine-preventable diseases is significantly higher than the risk from the vaccine itself. (McLean HQ et al. JAMA. 2017;318(4):335–346)

Vaccines are backed by science, supported by decades of real-world data, and trusted by the global medical community. They are a cornerstone of preventive health for children and adults alike.

Why Vaccination Helps Protect Everyone

Vaccination protects not only the person receiving the shot but also everyone around them.

When enough people are vaccinated, disease transmission slows and sometimes stops. This helps protect those who cannot receive vaccines or may not develop a strong immune response.

Vaccination helps protect:

  • Babies who are too young to be vaccinated

  • People undergoing cancer treatment or living with immune system conditions

  • Pregnant individuals and older adults who are at higher risk for complications

This concept is called herd immunity or community protection. It is a powerful way to shield our most vulnerable neighbors.

By vaccinating your child, you are doing more than protecting them. You are building a wall of protection around your school, neighborhood, and community. This shared responsibility helps keep everyone healthier and safer.