Booster dose of COVID-19 vaccine and its effectiveness against post COVID-19 condition in individuals with pre-existing immunity: a sequential propensity score-matched cohort study
Summary Background COVID-19 vaccination before primary infection is associated with decreased risk for post COVID-19 condition, but its effectiveness in populations with pre-existing immunity against SARS-CoV-2 is unknown. Our aim was to assess the COVID-19 vaccine effectiveness against post COVID-19 condition of four...