Influences of vaccination and public health strategies on COVID-19 dynamics in the United States: Evaluating policy impacts, behavioral responses, and variant proliferation

Background and Aim: The United States (US) government implemented interventions against COVID-19, but their effects on variant-related risks remain inconclusive. We aimed to assess the causal effects of vaccination rates, booster uptakes, face mask mandates, and public area mobility (societal behavioral factor) on early-stage COVID-19 case and death growth rates and identify the most effective public health response for controlling COVID-19 in the US. Materials and Methods: We performed retrospective analyses using four standard correlated random effects models, analyzing a robust panel dataset that encompasses 16,700 records across all fifty US states. Models 1 and 3 analyzed COVID-19 case rates and death growth rates, respectively, from January 2021 to November 2021. In contrast, using the data from August 2021 to November 2021, Models 2 and 4 assessed the effect of Delta variants and booster shots on COVID-19 case and death growth rates, respectively. Results: We found that face mask mandate (p < 0.01) and workplace mobility (p < 0.05) led to lower COVID-19 case growth rates. COVID-19 vaccination uptake rate reduced COVID-19 death growth rates (p < 0.01). Furthermore, contrary to Epsilon variant (p < 0.01), which contributed to reduced COVID-19 case growth rates, Delta variant led to significant increases in COVID-19 cases (p < 0.001). Conclusion: This study suggests that immediate public health interventions, like mask mandates, are crucial for crisis mitigation, while long-term solutions like vaccination effectively address pandemics. The findings of this study not only sheds light on the recent pandemic but also equips policy-makers and health professionals with tools and knowledge to tackle future public health emergencies more effectively. Keywords: COVID-19, face mask mandate, public mobility, vaccination, variants.