The impact of government-mandated proof of vaccination requirements on COVID-19 vaccine uptake

Vaccination has proven to be particularly effective in decreasing the transmission and severity of SARS-CoV-2 infection, with vaccinated individuals having a significantly lower chance of severe consequences. Nonetheless, CoV disease 2019 (COVID-19) vaccinations in several countries noticeably dropped in the summer months after a high surge in early 2021. Due to the enhanced reproduction rate of the SARS-CoV-2 Delta variant, even regions with heightened vaccination rates witnessed elevated viral spread or had to continue or reinstate non-pharmaceutical measures such as indoor capacity restrictions or mask-wearing in fall 2021.