Topic Menu

Childhood Immunization Rates

Contact Info

Infectious Disease Epidemiology, Prevention and Control Division

651-201-5414

IDEPC Comment Form

Contact Info

Infectious Disease Epidemiology, Prevention and Control Division

651-201-5414

IDEPC Comment Form

About Childhood Immunization Rates from NIS and MIIC

Detailed description of the differences between childhood immunization rates from the National Immunization Survey (NIS) and the Minnesota Immunization Information Connection (MIIC).

Updated 12/2023

On this page:
Source
Who is assessed?
How are the rates generated?
Are there differences in how vaccine coverage is defined?
How valid are the rates?
How current are the rates?
Additional resources

Source

National Immunization Survey (NIS)	Minnesota Immunization Information Connection (MIIC)
Centers for Disease Control and Prevention (CDC).	Minnesota Department of Health (MDH).

Who is assessed?

NIS	MIIC
A random sample of children age 19 through 35 months. Sub-analysis available by age, state, some local areas, race/ethnicity, WIC participation status, poverty status, health care provider type, and rural versus urban residence.	Minnesota children age 24 through 35 months in the MIIC immunization information system. Sub-analysis available by county and other variables, as requested.

How are the rates generated?

NIS	MIIC
Minnesota rates are based on a surveyed sample of approximately 250 Minnesotans for each birth year. The CDC contacts a random sample of families by phone to ask about their children's vaccination histories and checks this information against providers' vaccination records.	Birth year calculations are based on MIIC records of the approximately 70,000 children born each year with a Minnesota address in MIIC.

Are there differences in how vaccine coverage is defined?

There are differences in how the two data sources define coverage with Hib (Haemophilus influenzae type b), varicella (chickenpox), and PCV (pneumococcal conjugate vaccine), as well as with any series that includes these vaccines.

NIS	MIIC
The "full series" of Hib vaccine contains either 3 or 4 doses, depending on the vaccine brand.	"Complete Hib” coverage can include 2, 3, or 4 doses, depending on the vaccine brand and age at first dose.
Varicella coverage is unadjusted for history of disease.	Varicella coverage is adjusted to take into account history of disease.
A child is considered covered by PCV if he or she has had at least 4 doses.	"Complete PCV" coverage can be 2, 3, or 4 doses, depending on age at first dose.
Vaccine series definitions incorporate the specifications above.	Vaccine series definitions incorporate the specifications above.

How valid are the rates?

NIS	MIIC
Minnesota rates are based on a surveyed sample of approximately 250 Minnesotan children for each birth year. Each estimate is accompanied by a "confidence interval," indicating 95 percent likelihood that the true rate falls within this range. Accuracy of the NIS coverage estimates are affected by: Survey design, Statistical adjustments used in calculating rates, and Parental and provider knowledge of child vaccination history.	Birth year calculations are based on MIIC records of approximately 70,000 children born each year with a Minnesota address in MIIC. MIIC data may underestimate the actual percent of children receiving vaccines because: Health care provider participation in MIIC is voluntary, MIIC may include children who have moved, and Cross border-state immunization data exchange is limited to Wisconsin and North Dakota. Although approximately 94 percent of Minnesota Vaccines for Children (MnVFC) health care providers routinely submit immunization data to MIIC, not all those who submit data enter every administered vaccine or every historical vaccination their patients report. When a child moves out of Minnesota, their MIIC record may not be updated, and they may still be included in the denominator used to calculate the proportion of children receiving vaccines.

NIS

MIIC

Minnesota rates are based on a surveyed sample of approximately 250 Minnesotan children for each birth year.
Each estimate is accompanied by a "confidence interval," indicating 95 percent likelihood that the true rate falls within this range.
Accuracy of the NIS coverage estimates are affected by:
- Survey design,
- Statistical adjustments used in calculating rates, and
- Parental and provider knowledge of child vaccination history.

Birth year calculations are based on MIIC records of approximately 70,000 children born each year with a Minnesota address in MIIC.
MIIC data may underestimate the actual percent of children receiving vaccines because:
- Health care provider participation in MIIC is voluntary,
- MIIC may include children who have moved, and
- Cross border-state immunization data exchange is limited to Wisconsin and North Dakota.
Although approximately 94 percent of Minnesota Vaccines for Children (MnVFC) health care providers routinely submit immunization data to MIIC, not all those who submit data enter every administered vaccine or every historical vaccination their patients report.
When a child moves out of Minnesota, their MIIC record may not be updated, and they may still be included in the denominator used to calculate the proportion of children receiving vaccines.

How current are the rates?

NIS	MIIC
NIS surveys are conducted throughout the calendar year and new birth year results are published in the fall of each year. Rates reflect immunization practices 2 to 4 years in the past.	Birth year MIIC rates are calculated based on records of children born during that calendar year that currently have a Minnesota address in MIIC.

Additional resources

Childhood Immunization Rates
Links to current Minnesota rates, rates over time by single antigen and series, and rates by county.
Minnesota Immunization Information Connection (MIIC)
Information about the statewide immunization registry, MIIC.
ChildVaxView
NIS data for the nation, regions, states, and some local areas from the Centers for Disease Control and Prevention.
Minnesota Public Health Data Access: Immunizations
Interactive maps and tables showing MIIC-based immunization rates. Rates are available for single antigens and the childhood series by county and seven-county metro area ZIP codes.