Comparative evaluation of SARS-CoV-2 serological tests shows significant variability in performance across different years of infection and between the tests oleh Dell-Dylan Kenfack, Georges Nguefack-Tsague, Veronique B Penlap, Martin F Maidadi, Celestin Godwe, Nico F Njayou, Jude D Bigoga, Francine Ntoumi, Eitel Mpoudi-Ngole, Marcel Tongo