Immunization is the process of developing immunity, most often through vaccines. Vaccines train the immune system to recognize and fight infections in a safe way. They greatly reduce the chance of getting sick, needing hospital care, or dying from infectious diseases. When many people are vaccinated, it also helps protect the community by slowing the spread of disease, including protecting people who cannot get vaccinated. Vaccines may cause mild side effects like tiredness or soreness for a short time, but the protection they provide can last for many years or even a lifetime.
Infections can be unpredictable and serious, even when symptoms are mild or not noticeable. Vaccines help the body build protection before exposure, which is important because it may be too late to prevent illness after infection. Some vaccines need more than one dose to give full protection, and boosters may be needed over time.
See “Additional Resources ” to learn more about the benefits and possible risks of vaccines.
During the 2023–2024 flu season, American Indian/Alaska Native (AI/AN) adults got the flu vaccine 23% less often than U.S. adults overall.
AI/AN children born in 2020 were 16% less likely to be fully vaccinated by age 2 compared with all U.S. children born that year.
Additional Resources
MedlinePlus
U.S. Centers for Disease Control and Prevention (CDC)
Further Reading
Diphtheria-Tetanus (DTaP)
Children
Children born in 2020 who received at least 4 doses of the diphtheria-tetanus-acellular pertussis (DTaP) vaccine by age 24 months, percentage AI/AN* Total Population Ratio (AI/AN* / Total) 73.2 80.7 0.91
Source: U.S. Centers for Disease Control and Prevention. (2023). National Immunization Survey-Child, United States, 2017-2022 Haemophilus Influenzae Type B (Hib)
Children
Children born in 2020 who received the full series (either a 3-dose series or a 4-dose series depending upon the product type) of the Haemophilus influenzae type b (Hib) vaccine by age 24 months, percentage AI/AN* Total Population Ratio (AI/AN* / Total) 67.5 78.2 0.86
Source: U.S. Centers for Disease Control and Prevention. (2023). National Immunization Survey-Child, United States, 2017-2022 Hepatitis A
Adolescents
Adolescents ages 13–17 who received at least two doses of the hepatitis A vaccine, percentage, 2024 AI/AN* Total Population Ratio (AI/AN* / Total) 90.0 87.1 1.03
Source: U.S. Centers for Disease Control and Prevention. (2024). TeenVaxView interactive Children
Children born in 2020 who received at least two doses of the hepatitis A vaccine by age 24 months, percentage AI/AN* Total Population Ratio (AI/AN* / Total) 41.5 47.3 0.88
Source: U.S. Centers for Disease Control and Prevention. (2023). National Immunization Survey-Child, United States, 2017-2022 Hepatitis B
Adolescents
Adolescents ages 13–17 who received at least three doses of the hepatitis B vaccine (HepB), percentage, 2024 AI/AN* Total Population Ratio (AI/AN* / Total) 92.7 92.2 1.01
Source: U.S. Centers for Disease Control and Prevention. (2024). TeenVaxView interactive Children
Children born in 2020 who received at least 3 doses of the hepatitis B (Hep B) vaccine by age 24 months, percentage AI/AN* Total Population Ratio (AI/AN* / Total) 92.6 91.5 1.01
Source: U.S. Centers for Disease Control and Prevention. (2023). National Immunization Survey-Child, United States, 2017-2022 Human Papillomavirus (HPV)
Adolescents
Adolescents ages 13–17 who received at least one dose of the human papillomavirus (HPV) vaccine, percentage, 2024 AI/AN* Total Population Ratio (AI/AN* / Total) Male 78.8 77.4 1.02 Female 70.1 79.1 0.89 Both Sexes 74.1 78.2 0.95
Source: U.S. Centers for Disease Control and Prevention. (2024). TeenVaxView interactive Influenza
Adults
Adults ages 18 and over who received the flu vaccine, percentage, 2023–2024 season AI/AN* Total Population Ratio (AI/AN* / Total) 34.7 44.9 0.77
Source: U.S. Centers for Disease Control and Prevention. (2024). Flu vaccination coverage by race/ethnicity, adults 18 years and older, United States, Behavioral Risk Factor Surveillance System, 2023-24 season Adults ages 65 and older who received the influenza (flu) vaccine, percentage, 2023–2024 season AI/AN* Total Population Ratio (AI/AN* / Total) 52.1 69.7 0.75
Source: U.S. Centers for Disease Control and Prevention. (2024). Flu vaccination coverage by race/ethnicity, adults 18 years and older, United States, Behavioral Risk Factor Surveillance System, 2023-24 season Measles, Mumps, and Rubella (MMR)
Adolescents
Adolescents ages 13–17 who received at least two doses of the measles, mumps, and rubella (MMR) vaccine, percentage, 2024 AI/AN* Total Population Ratio (AI/AN* / Total) 94.2 92.6 1.02
Source: U.S. Centers for Disease Control and Prevention. (2024). TeenVaxView interactive Children
Children born in 2020 who received at least 1 dose of the measles-mumps-rubella (MMR) vaccine by age 24 months, percentage AI/AN* Total Population Ratio (AI/AN* / Total) 89.1 91.4 0.97
Pneumonia
Adults
Adults ages 18 and over who ever received the pneumococcal (pneumonia) vaccine, percentage, 2024 AI/AN Total Population Ratio (AI/AN / Total) 20.3 25.1 0.81
Source: U.S. Centers for Disease Control and Prevention, National Center for Health Statistics. (2025). Interactive summary health statistics for adults: Percentage of ever receiving a pneumonia (pneumococcal) vaccine for adults aged 18 and over, United States, 2024 Polio
Children
Children born in 2020 who received at least 3 doses of the polio vaccine by age 24 months, percentage AI/AN* Total Population Ratio (AI/AN* / Total) 89.9 92.9 0.97
Source: U.S. Centers for Disease Control and Prevention. (2023). National Immunization Survey-Child, United States, 2017-2022 Rotavirus
Children
Children born in 2020 who received at least 2 or at least 3 doses of the rotavirus vaccine (depending upon the product type) by age 24 months, percentage AI/AN* Total Population Ratio (AI/AN* / Total) 69.0 76.4 0.90
Source: U.S. Centers for Disease Control and Prevention. (2023). National Immunization Survey-Child, United States, 2017-2022 Tetanus-Diphtheria (Tdap)
Adolescents
Adolescents ages 13–17 who received at least one dose of the tetanus-diphtheria (Tdap) booster H, percentage, 2024 AI/AN* Total Population Ratio (AI/AN* / Total) 89.4 91.3 0.98
Source: U.S. Centers for Disease Control and Prevention. (2024). TeenVaxView interactive Varicella (Chicken Pox)
Children
Children born in 2020 who received at least 1 dose of the varicella (chicken pox) vaccine by age 24 months, percentage AI/AN* Total Population Ratio (AI/AN* / Total) 84.3 91.2 0.92
Source: U.S. Centers for Disease Control and Prevention. (2023). National Immunization Survey-Child, United States, 2017-2022 No Vaccinations
Children
Children born in 2020 who received no vaccinations by age 24 months, percentage AI/AN* Total Population Ratio (AI/AN* / Total) 1.0 1.0 1.00
Source: U.S. Centers for Disease Control and Prevention. (2023). National Immunization Survey-Child, United States, 2017-2022 Fully Immunized
Children
Children born in 2020 who were fully immunized (combined 7-vaccine series) by age 24 months, percentage AI/AN* Total Population Ratio (AI/AN* / Total) 56.7 67.9 0.84
Source: U.S. Centers for Disease Control and Prevention. (2023). National Immunization Survey-Child, United States, 2017-2022 *Population is non-Hispanic in the data source.
