Evaluation of long-term antibody kinetics in healthcare workers vaccinated with inactivated COVID-19 Vero cell vaccine (CoronaVac), a propensity score-matched observational study oleh Yesim Yildiz, Hasan Selcuk Ozger, Esin Senol, Resul Karakus, Merve Buyukkoruk, Fatma Betul Altin, Fatma Zehra Ozcan, Melek Yaman, Nihan Oruklu, Aysegul Atak Yucel, Emin Umit Bagriacik