Evidence on trends in uptake of childhood vaccines and association with COVID-19 vaccination rates.

Abstract

Importance: Childhood vaccination rates have declined in recent years; there is also concern that resistance to COVID-19 vaccines could spill over to childhood vaccines.

Objectives: To use local-level data to study trends in childhood vaccination rates and heterogeneity in local rates; including how many areas are below herd-immunity thresholds, and assess the association between COVID-19 vaccine hesitancy and childhood vaccination.

Design: We report, for 11 states with available data, vaccination rates for measles, mumps, rubella (MMR), and diphtheria, tetanus, acellular pertussis (DTaP) vaccines, including percentage of schools/counties with rates ≥95 %, 90-95 %, 80-90 %, and < 80 %. We also study the association between county-level COVID-19 vaccination rates and change from 2019 to 2022 in MMR and DTaP vaccination rates.

Exposure: School/county level vaccination rates; county-level COVID-19 vaccine hesitancy, proxied by the percent of the adult population in each county that did not complete primary COVID-19 vaccination.

Main outcomes: Percentage of school/counties with MMR/DTaP vaccination rates within specified ranges, mean vaccination rates, and change in MMR/DTaP vaccination rates between 2019 and 2022.

Results: On average, childhood vaccination rates declined from 2019 to 2022 in states that allow non-medical exemptions, but with substantial heterogeneity within and across states. The largest declines were in already low-vaccination schools. COVID-19 vaccine hesitancy was associated with a somewhat larger 2019-to-2022 decline in childhood vaccination rates in rural counties and strongly Republican-leaning counties.

Conclusion: Vaccination rates fell from 2019 to 2022, continuing a longer trend toward lower rates. For measles and pertussis, childhood vaccination rates are below herd-immunity levels in many local communities, sometimes substantially so. We used two proxies for potential spillover of COVID-19 vaccine hesitancy to childhood vaccines (rural indicator and Republican-leaning indicator); these proxies can explain a modest part of the decline childhood vaccination in rural and Republican-leaning counties, but most of the explanation lies elsewhere.