Exploring the relationship between political partisanship and COVID-19 vaccination rate

Background Although increasing COVID-19 vaccination rates is critical to end the pandemic, vaccination goals are far from being achieved. Political partisanship may be a risk factor for getting the COVID-19 vaccine. This study examines the association between the political partisanship and vaccination rate at the county-level and quantifies the differences between the Democratic and Republican parties. Methods Data are from CDC, the NY Times, and the US Census and American Community Survey. Linear regressions are used to test the relationships between the political partisanship and COVID-19 vaccination rate at the county level. The dependent variable is the cumulative COVID-19 vaccination rate each month between January and August, 2021 and the explanatory variables are the county political partisanship and interaction terms between political partisanship and time dummies during the study period. Results Republican counties consistently had lower vaccination rates than Democratic counties, and the gap in vaccination rates between a typical Democratic and Republican county has steadily widened by month. Conclusion The COVID-19 vaccination rate is strongly associated with political partisanship. The political nature of this pandemic has created gaps in vaccination rates along party lines and will continue to be a barrier in mitigating this public health crisis.