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Immunizations Data: Impact of COVID-19 on Routine Vaccination

Rates for routine vaccines have changed in recent years. The COVID-19 pandemic caused a large disruption to the health care system. Many Wisconsinites missed routine doctor’s visits. As a result, children and teenagers fell behind schedule for vaccines.

Missed or delayed vaccinations are a problem. Delaying vaccination leaves people more vulnerable to preventable diseases. High vaccination rates are key to protect Wisconsin communities from future outbreaks.

To stay healthy and prevent future outbreaks, people need to get caught up on vaccines. Let’s work together to help more Wisconsinites get protected by vaccines.

Learn more about childhood and adolescent vaccines

Percent change of vaccination rates

The data below shows how the pandemic affected routine vaccination rates of Wisconsin residents. The graph compares quarterly vaccination rates to the average rates of the three years before the pandemic.

This dashboard looks at the percent change in vaccination rates. We compared recent vaccination rates to the average rates before the COVID-19 pandemic. In the dashboard you can hover over a quarter to view the data.

A negative percent change means less people got vaccinated than before the pandemic. We show this with a blue bar in the graph that is pointing downward. A positive percent change means more people got vaccinated in the quarter compared to the 2017-2019 average. We show this with a purple bar in the graph that is pointing upward.

The pandemic's impact on rates varies by vaccine. Variation may be due to vaccine specific trends and the recommended age of a vaccination. When interpreting the data consider the cohorts age at the start of the pandemic. For example, the largest percent change for the MMR vaccine was in quarter 1 of 2021. The CDC (Centers for Disease Control and Prevention) recommends children receive the MMR vaccine at 12 months of age. Children in the 2021 cohort would have been 12-months old in 2020. The COVID-19 pandemic may have disrupted their MMR vaccination at 12 months.

Data source: The Wisconsin Immunization Registry (WIR)
Individuals who have deceased or asked to be removed from the registry are not included in the cohorts.

Reporting to WIR is not required for all vaccines given. Reporting to WIR is only mandatory in certain circumstances.

  • The Vaccines for Children (VFC) program requires VFC providers report all doses given to WIR.
  • According to Wisconsin Legislature Wis. Stat. § 450.035: A pharmacist, pharmacy technician, or person engaged in the practice of pharmacy under Wis. Stat. § 450.03 (1) (f), (fm), or (g) who administers a vaccine to a person under this section shall update, or cause a pharmacy to update, the Wisconsin Immunization Registry established by the department of health services within 7 days of administering the vaccine.
  • According to Wisconsin Legislature Wis. Stat. § 447.059: A dentist who administers a vaccine under sub. (1) shall update the Wisconsin Immunization Registry established by the department of health services within 7 days of administering the vaccine.

Vaccinations: The following are the vaccines or vaccine series in the dashboard and their definitions

  • Child series (4:3:1:3:3:1:4) —at least 4 DTaP, 3 Polio, 1 MMR, 3 Hib, 3 HepB, 1 Varicella and 4 PCV doses
  • DTaP (4)- 4 or more doses of diphtheria-tetanus-acellular pertussis vaccine
  • HepA (1)— 1 or more doses of hepatitis A vaccine
  • HepA (2)— 2 or more doses of hepatitis A vaccine
  • HepB (3)- 3 or more doses of hepatitis B vaccine
  • Hib (3)— 3 or more doses of Haemophilus influenzae type b vaccine
  • MMR (1)— 1 or more doses of measles, mumps, rubella vaccine
  • PCV (4) —4 or more doses of pneumococcal conjugate vaccine
  • Polio (3) —3 or more doses of the polio vaccine
  • Varicella (1)— 1 or more doses of varicella (chickenpox) vaccine

Time frame: Data is reported by quarter from 2020 through current. Quarters are based on the calendar year. Quarter 1 is January–March. Quarter 2 is April–June. Quarter 3 is July–September. Quarter 4 is October–December.

Percent Change: The percent change is the relative change from an old to a new value. The following formula was used to calculate the percent change. ((X2 - X1)/X1) * 100

Data shown are subject to change. For example, it may change if we remove duplicate records or if historical vaccinations are added into WIR.

MMR vaccination rates by county

Glossary

 
Last revised April 17, 2025