Essential Guide to Childhood Vaccines and Health

Vaccines remain one of the most effective public health interventions ever developed. Before widespread immunization, infectious diseases routinely caused severe illness, permanent disability, and death in infants, children, and adults. Diseases such as smallpox — which killed hundreds of millions globally — were eradicated only through coordinated vaccination efforts. Others, like polio, once a leading cause of paralysis in the United States, have been eliminated domestically for decades due to sustained immunization programs.

Despite evolving public health policies and ongoing discussion around vaccination, the medical science underlying immunization has not changed. Vaccines continue to prevent serious illness, protect vulnerable populations, and reduce strain on healthcare systems.

How Vaccines Protect Children

Infants are born with some protection from their mother’s immune system, but their developing immune systems cannot yet defend effectively against certain dangerous infections. While babies can fight many everyday germs, they remain particularly vulnerable to diseases that vaccines are designed to prevent.

Vaccines work by introducing safe components (weakened, dead, or just a small piece) of a germ — called antigens — that train the immune system to recognize and respond quickly to real infections. This process allows the body to build immunity without the child having to experience the disease itself. Following the recommended immunization schedule ensures protection is in place at the ages when children are most at risk.

Vaccines are developed only for diseases that have caused significant harm to children—serious illness, hospitalization, lifelong complications, or loss of life. Each vaccine on the schedule protects against a disease that posed a real threat before immunization was available. In short, we don’t create vaccines for illnesses that aren’t dangerous. We vaccinate against diseases that truly matter.

The Importance of Following the Recommended Schedule

The childhood immunization schedule is carefully designed to protect children from 14 potentially serious or life-threatening diseases by age two, with additional vaccines offered throughout childhood and adolescence to maintain protection. Some vaccines require multiple doses to achieve full immunity, making timely vaccination critical.

Delaying or skipping vaccines increases the risk of infection; not only for individual children, but for the broader community.

Our Commitment to Evidence-Based Care

Oklahoma Children’s remains committed to evidence-based medicine and the health and safety of the patients and communities we serve.

As Oklahoma’s flagship children’s hospital and academic health system, our clinical teams utilize guidelines from a broad range of scientific and professional organizations, including the American Academy of Pediatrics (AAP), American Academy of Family Physicians (AAFP), and the American College of Obstetricians and Gynecologists (ACOG). We rely on these established standards to ensure our patients receive care that reflects the most current scientific evidence and clinical best practices. We understand families may have questions about evolving immunization guidance. We encourage these conversations with your personal healthcare provider, who can offer recommendations based on your family’s unique health needs. Routine immunizations remain a safe and effective foundation for public health and are accessible at our facilities statewide.

Diseases Prevented by Routine Childhood Vaccination

Routine immunization protects against many serious illnesses, including:

• Measles
• Pertussis (whooping cough)
• Polio
• Tetanus
• Diphtheria
• Influenza (flu)
• Hepatitis A and B
• Pneumococcal disease
• Haemophilus influenzae type b (Hib)
• Rotavirus
• Mumps
• Rubella
• Chickenpox (varicella)

Several of these diseases are currently circulating in the United States. Measles outbreaks have occurred and continue to occur across multiple states, and pertussis cases are significantly elevated this year. These illnesses are not theoretical risks, they are present now and disproportionately affect infants, young children, and those with weakened immune systems.

Herd Immunity Is Becoming Less Reliable

Community or “herd” immunity has historically helped protect individuals who could not be vaccinated, such as infants too young for certain vaccines or patients with medical contraindications. However, as vaccination rates decline in some communities, herd immunity may no longer provide reliable protection.

Families who have relied on community protection alone may want to reconsider, as declining vaccination rates place unvaccinated children at increased risk of infection. When fewer people are vaccinated, outbreaks spread more easily, increasing risk for everyone, especially those with no ability to protect themselves.

Increased Risk for Vulnerable Patients

Lower immunization rates create a more dangerous environment for children and adults with underlying medical conditions, including:

• Diabetes
• Congenital or acquired heart disease
• Transplant recipients
• Cancer patients
• Individuals with immune-compromising conditions
• Children who cannot be vaccinated for medical reasons

For these patients, exposure to vaccine-preventable diseases can lead to severe complications, prolonged hospitalization, or death. Immunization is not only a personal health decision, it is a critical layer of protection for the most vulnerable members of our communities.

Overview of the Childhood Immunization Schedule

While the schedule can appear complex, pediatricians are available to guide families and ensure vaccines are administered safely and on time.

Key milestones include:

At Birth

• Hepatitis B (within 24 hours)

1–6 Months

• DTaP, Hib, Polio, Pneumococcal, Rotavirus
• Completion of Hepatitis B series
• Annual influenza vaccination beginning at 6 months
• COVID-19 vaccination as age-appropriate and recommended by your child’s healthcare provider

7–23 Months

• MMR, Varicella, Hepatitis A
• Booster doses of DTaP, Hib, Pneumococcal, and Polio
• Annual influenza vaccination

Early Childhood and School Age

• Booster doses of DTaP, Polio, MMR, and Varicella
• Ongoing annual flu vaccination
• COVID-19 boosters as recommended by your child’s healthcare provider

Adolescence

• Tdap
• HPV
• Meningococcal vaccines
• Annual influenza vaccination

Your child’s pediatrician can help tailor this schedule to individual health needs while maintaining full protection.

Addressing Vaccine Hesitancy

Concerns about vaccines are common, especially in an environment where misinformation spreads quickly. It is important to rely on credible medical evidence and trusted healthcare professionals.
Key facts to remember: