The meaning of SARS-CoV-2 antibodies in a patient with a systemic reaction to the mRNA-1273 SARS-CoV-2 vaccine after previous natural immunization

Abstract

Objectives: There is limited experience regarding the meaning of SARS-CoV-2 antibodies after vaccination in patients with naturally acquired immunity. Methods: We describe the case of a patient who received the first dose of the mRNA-1273 SARS-CoV-2 vaccine 6 months after his recovery from moderately severe COVID-19. Results: Our patient had a positive nucleocapsid SARS-CoV-2 IgG/IgM titre with 78.7 multiple of cut-off indicating persistent humoral immune response 6 months after infection. After vaccination, he developed prolonged systemic symptoms (fever, fatigue, nausea, diarrhoea and myalgia) for a duration of 6 days. Conclusion: SARS-CoV-2 nucleocapsid antibodies provide information about naturally acquired immunity. For the assessment of immune response to vaccination, measurement of the SARS-CoV-2 spike antibody titre before and after vaccination is essential. Patients with naturally acquired immunity might develop a prolonged systemic reaction to the first dose of the mRNA-1273 SARS-CoV-2 vaccine.