Completion rates for key childhood vaccines among toddlers fell from nearly 76% in 2017 to 67% in 2023, while adolescent vaccination rates dropped from about 81% to 75% during the same period.

This decline in immunization rates was particularly pronounced in counties with lower household incomes and higher uninsurance rates, creating or widening gaps in vaccination coverage among different populations.

The study highlights the impact of the COVID-19 pandemic, which interrupted previously increasing trends in immunizations, especially for the human papillomavirus (HPV) vaccinations.

While the HPV vaccination series saw modest increases in completion rates, rising from 35% to 42% for males and from 43% to 45% for females, these rates still lagged behind pre-pandemic growth trends.

In 2025, Michigan reported a resurgence of vaccine-preventable diseases, including over a dozen measles cases and 855 cases of pertussis, underscoring the urgency of reversing declines in immunization rates.

A recent study led by Michigan Medicine reveals a significant decline in routine childhood and adolescent immunizations in Michigan from 2017 to 2023, largely influenced by socioeconomic factors such as household income and insurance coverage.

To combat these challenges, the authors of the study emphasize the need for broad-based efforts to increase immunization rates, particularly targeting counties with lower incomes and higher uninsurance rates.