Data Management Statistics

Manager:  Erica Hunter, PhD

Immunization statistics

Immunization statistics are gathered nationally and locally to ensure that children receive appropriate and timely immunizations so as to prevent the occurrence of vaccine-preventable diseases.   The National Immunization Survey (NIS) is performed by the Centers for Disease Control and Prevention (CDC) and collects statistics for each state on the immunization coverage of children 19-35 months of age.  Recently CDC has broadened NIS to include adolescents, 13-17 years of age. The Virginia Department of Health (VDH) conducts an annual immunization survey for the children enrolled in kindergarten, daycare, headstart programs, and 7th grade. The objective of both surveys is to measure the progress towards having all children receive the recommended immunizations by two years of age and at school entry to assess compliance with attendance requirements.  In addition, each state Health department collects data on various health behavior and risk factors for disease, including adult immunization, which are reported to CDC (BRFSS).   All of these surveys contribute to the Healthy People 2020 objectives with the ultimate goal of improving the Nation’s health.

Assessment Definitions

95% Confidence Interval (CI) – a concept from random sampling theory where an estimate of the coverage rate in a large population is produced from the rate found in a randomly selected group of children who are part of the large group.  The CI indicates that if the survey were repeated over and over, 95% of the surveys would produce a coverage estimate falling within the range of the 95% CI.  For example, a rate of 75% ± 2% has a confidence interval of 2%.  This means that the estimated coverage rate is actually between 73% and 77%.

Vaccines Recommended by the Advisory Committee on Immunization Practices (ACIP) – The role of this committee is to provide advice that will lead to a reduction in the incidence of vaccine preventable diseases in the United States, and an increase in the safe use of vaccines and related biological products.

DTaP- Diphtheria, Tetanus and Pertussis vaccines; although some children may have received DTP instead of DTaP, they are not differentiated. The standard is four doses by 24 months of age.
HepB- Hepatitis B vaccine. The standard is three doses by 24 months of age.
HiB- Haemophilus influenza, type B vaccine. The standard is four doses by 24 months of age.
MCV4- Meningococcal conjugate vaccine. The standard is one dose at age 11-12 with a booster dose at age 16 years.
MMR- Refers to the measles, mumps, and rubella combination vaccine. The standard is one dose by 24 months of age and a second does at 4-6 years of age.
PCV- Pneumococcal conjugate vaccine. The standard is four doses by 24 months of age.
Polio- Refers to both oral polio vaccine and injectable polio vaccine. The standard is three doses by 24 months and an additional dose at 4-6 years of age.
Td/Tdap- Diphtheria, Tetanus and Pertussis vaccine (adolescent). Persons aged 11 years or older who have not received Tdap should receive a dose followed by Td booster every 10 years thereafter.
Var- Varicella vaccine (Chickenpox). The standard is one dose by 15 months of age and a second dose at 4-6 years of age.

Vaccination Series– When reporting immunization rates, it is often convenient to combine single antigens into groups of age-appropriate doses that are recommended by ACIP.  Some examples of series are:

4-3-1-3-3, which is 4 doses of DTaP, 3 Polio, 1 MMR, 3 HiB and 3 HepB

4-3-1-3-3-1-3, which is the above series plus 1 Var and 3 PCV.

4-3-1-3-3-1-4, which is the above series, plus an additional dose of PCV