Immunization
Ages 3-6 (Preschool)
Note
*: Statistically unstable
4:3:1:3:3:1:4 = ≥4 doses DTaP (diphtheria, tetanus toxoids, and acellular pertussis vaccine), ≥3 doses Polio (poliovirus vaccine), ≥1 dose MMR (measles, mumps, and rubella vaccine), ≥3 doses Hib (Haemophilus influenzae type b vaccine), ≥3 doses HepB (hepatitus B vaccine), ≥1 dose varicella vaccine, and ≥4 doses PCV (pneumococcal conjugate vaccine).
Tdap= tetanus, diphtheria, and acellular pertussis vaccine; MenACWY= quadrivalent meningococcal conjugate vaccine; HPV= human papillomavirus vaccine
The recommended schedule of vaccinations for adolescents includes vaccines to protect against: Tetanus-Diphtheria-Pertussis (Tdap), meningococcal disease (meningitis – MenACWY), and human papillomavirus (HPV). Most of these vaccines are recommended for 11- to 12-year olds. The HPV vaccinations are recommended to start at ages 11–12, continuing at ages 14 and 15 as a two- or threeshot series depending on the health status of the adolescent. The meningitis MenACWY vaccine is recommended at ages 11–12, with a booster shot recommended at age 16.
Data not available:
Adolescent ages 11-17 and Race-Ethnicity of Children (19-35 months) for 2013, 2016-2017
Race-Ethnicity categories:
Hispanic/Latino, Other
Source:
San Diego RDD (Random Digit Dialing) Immunization Survey conducted every third year by the County of San Diego Health and Human Services Agency.
(Received date: 6/20/2025)
What is the indicator?
This indicator—the percentage of young children ages 19–35 months who have completed the recommended 4:3:1:3:3:1:4 childhood immunization series—tracks vaccine coverage during the early years of life. Although the full series is recommended by age 24 months, available data capture completion within a broader age range. In addition, adolescent immunization coverage rates—such as those for Tdap (tetanus, diphtheria, and pertussis), HPV (human papillomavirus), Varicella (chickenpox) and MenACWY (Meningitis) vaccines—are also monitored to assess protection among older youth. These data are collected every three years through the Immunization Survey conducted by the County of San Diego Health and Human Services Agency.
Why is this important?
Immunization is essential at every stage of life. Childhood vaccines play a critical role in public health, protecting against serious diseases like measles, polio, and whooping cough. They are safe, effective, and provide immunity before exposure, helping to protect both individuals and communities by limiting disease spread. However, disparities in vaccination rates often reflect barriers such as limited healthcare access, socioeconomic challenges, and public mistrust. Children who are not fully vaccinated face greater health risks and may pose a threat to others. Adolescent immunization is also a key priority. Vaccines for Tdap (tetanus, diphtheria, and pertussis), HPV (human papillomavirus), and meningococcal disease are recommended by national medical organizations including the Advisory Committee on Immunization Practices (ACIP), the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and the American Medical Association (AMA). Tracking adolescent vaccine coverage ensures continued protection through the teen years and strengthens long-term public health outcomes. Promoting timely and equitable vaccination across childhood and adolescence is essential to building healthier, more resilient communities.
What strategies can make a difference?
These evidence-based and best practices are used across the country to increase immunization rates:
- Implement broad and targeted campaigns to inform parents about the importance, safety, and benefits of vaccines for children, adolescents, adults, and seniors.
- Ensure vaccines are widely accessible through pediatricians, family physicians, health departments, community clinics, pharmacies, and other convenient locations, supported by adequate vaccine supply and funding.
- Provide outreach and intensive support for families with children who are not up-to-date on vaccines, including those facing access barriers or vaccine hesitancy.
- Use geographic mapping and immunization data to identify clusters of low coverage and focus outreach efforts accordingly; encourage provider participation in immunization registries.
- Promote laws limiting vaccine exemptions, educate health providers on the importance of vaccinating during all suitable visits, and regularly monitor immunization coverage through data collection and surveys.