CD40LG and infection: In this study, we measured the levels of IgG/IgM and neutralizing antibodies against SARS-CoV-2 in reverse transcriptase PCR (RT-PCR)-confirmed COVID-19 patients 225.5 (IQR, 219 to 232) days after symptom onset, in order to verify persistent immunity against SARS-CoV-2 natural infection and identify the changing tendencies of antibodies in the long term.