Stay-at-home orders might result in decreased accessibility to routine immunization services, leaving children at risk for vaccine-preventable diseases and their complications. This report evaluated whether vaccination coverage changed during the COVID-19 pandemic in Michigan.

The authors used data from the Michigan Care Improvement Registry to determine vaccination status of milestone age cohorts of children at ages 1, 3, 5, 7, 16, 19, and 24 months. They compared up-to-date status for individual vaccines and the recommended age-based vaccine series in May 2020 with points of time in May 2016–May 2019.

They found that vaccination coverage during the pandemic declined in all milestone age cohorts, except for birth-dose hepatitis B coverage, which is typically administered in the hospital setting. Among children aged 5 months, up-to-date status for all recommended vaccines declined from approximately 2/3 of children during 2016–2019 to fewer than half (49.7%) in May 2020. For the 16-month age cohort, coverage with all recommended vaccines declined, with measles-containing vaccination coverage decreasing from 76.1% in May 2019 to 70.9% in May 2020.

In addition to a decline in up-to-date status in almost all age cohorts, the number of noninfluenza vaccine doses administered and reported for children aged ≤18 years decreased 21.5%, and the number of doses administered to children aged ≤24 months decreased 15.5% during January–April 2020, compared with the same averaged periods in 2018 and 2019.

Up-to-date series coverage for each age cohort (1, 3, 5, 7, 16, 19, and 24 months) assessed in May 2020 was lower for Medicaid-enrolled children than for those children not enrolled in Medicaid.