Assessing the Shift in Reasoning for COVID-19 Vaccine Hesitancy in the United States Using a Six-Month Cross-Sectional Analysis from December 2020 to June 2021

PURPOSE: Vaccine hesitancy's increasing prevalence in the U.S. is hindering COVID-19 vaccination efforts. Understanding why individuals are vaccine hesitant can establish paths to increase vaccinations. As the COVID-19 vaccine landscape develops, reasons for hesitancy have likely shifted over time. METHODS & MATERIALS: We gathered 757,618 responses between December 6, 2020, and June 13, 2021, from a validated web survey administered by OutbreaksNearMe.org on Momentive.ai. From December 6 to January 11, individuals self-reported on willingness to receive a COVID-19 vaccine, and starting January 12, their COVID-19 vaccination status. Those who indicated being unsure or not planning to get vaccinated were prompted to report their reasoning (non-exclusive.) Proportions of reasoning were calculated as the number indicating that reason over the total question responses. Proportions were compared across time intervals with significant vaccine, pandemic guideline, and political occurrences. RESULTS: 47.1% of the study population are vaccinated, 11.5% are unsure about vaccination, and 11.9% have no plans to get vaccinated. Prior to vaccine approval, 47.2% indicated enough hesitancy to delay vaccination, and 10.8% indicated not wanting any potential COVID-19 vaccine. Overall, the top reported hesitancy reasons were ‘The vaccine being too new/not enough data’ (60.8%) and ‘Concerns about side effects’ (60.0%). ‘Lack of trust in government’ and ‘Lack of trust in scientists’ were less prevalent initially (28.1% and 11.0%), but have been increasing since January 2021, reaching 50.2% and 40.2% in June. ‘COVID-19 being an exaggerated threat’ also follows this trend, starting at 8.7% and reaching 31.6%. ‘Already had COVID-19’ and ‘Never get any vaccine’ are also increasing in prevalence across time, at a slower rate. Different hesitancy reasons have steeper increases throughout the study period corresponding to certain events like new guidelines for vaccinated persons. CONCLUSION: Concerns surrounding side effects and the vaccines’ newness were consistently the top reasons for COVID-19 vaccine hesitancy across the study population. Higher prevalence of lack of trust in government, science, and COVID-19 being exaggerated reasoning have been observed over time. Hesitancy reasoning seems somewhat influenced by significant events, however, those still not getting vaccinated have different reasoning for their hesitancy than was observed earlier in the pandemic.