Durable antibody response one year after hospitalization for COVID-19: A longitudinal cohort study

Abstract

Objectives Durability of the humoral immune response to SARS-CoV-2 has yet to be defined. We longitudinally evaluated during a 12-month period the antibody responses to SARS-CoV-2, and analysed predictors of antibody titres decline and seroreversion. Methods Prospective study conducted in a cohort of patients hospitalized for microbiologically-confirmed COVID-19. Blood and nasopharyngeal samples were sequentially obtained during hospital stay and at 1, 2, 6 and 12 months after patients’ discharge for measuring anti-spike (S) and anti-nucleocapsid (N) IgG antibody levels and SARS-CoV-2 RNA, respectively. Results 80 non-vaccinated patients were analysed. At month 12 after discharge, 73 (91.2%) patients exhibited detectable S-IgG and 35 (43.8%) N-IgG antibody titres. A gradual wane was observed in S-IgG and N-IgG antibody titres. Linear regression showed that S-IgG decline was positively associated with peak antibody titres (coefficient [95% CI] 0.059 [0.05–0.067], p < 0.001), inversely with WHO severity score (coefficient [95% CI] −0.042 [-0.079/-0.004], p = 0.033), and there was a trivial positive association with age (coefficient [95% CI] 0.002 [0–0.005], p = 0.10); N-IgG decline was positively associated with peak antibody titres (coefficient [95% CI] 0.091 [0.078–0.105], p < 0.001). Logistic regression showed that seroreversion for S-IgG was inversely associated with peak S-IgG (OR 0.19; 95% CI, 0.04-0.45; p = 0.004); seroreversion for N-IgG was inversely associated with peak N-IgG (OR 0.71; 95% 0.53–0.90; p = 0.009) and positively with cycle threshold of RT-PCR (OR 1.14; 95% CI, 1.00–1.33; p = 0.062). Conclusion Anti-spike IgG antibodies remain detectable one year after hospitalization for COVID-19. Higher peak antibody titres and disease severity were associated with increased durability of detectable antibodies.

Robust Neutralizing Antibody Levels Detected after Either SARS-CoV-2 Vaccination or One Year after Infection

“…In this study, we assessed longitudinally the humoral immune response in individuals after infection with or vaccination against SARS-CoV-2. Our data show that S-IgG is found in levels distinctly higher than the positive threshold in almost all participants about seven weeks after infection, followed by a steady decline over months consistent with studies released over the past year [17][18][19]. Even after more than one year, the majority of convalesced patients remained S-IgG seropositive, indicating a more stable and long-lasting antibody response than evidence from the earlier stages of the pandemic might have suggested [20,21].…”

Sequential Analysis of Binding and Neutralizing Antibody in COVID-19 Convalescent Patients at 14 Months After SARS-CoV-2 Infection

“…In our 8-month follow-up, we also reported that 76% of the patients still had detectable Neutralizing Antibodies (NAb) (1). Many studies reported short-term follow-up observations of less than 6 months (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15), whereas others reported longitudinal observations, typically spanning less than 12 months post symptom onset (1,4,(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27). Some studies reported contraction of anti-COVID humoral responses with a stronger initial decline (1,4,(23)(24)(25)27).…”

“…An important aspect of monitoring humoral responses has been having access to plasma from the same patients over 14 months. Most reports were based on cross-sectional analysis spanning less than 6 months (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) or up to 12 months (1,4,(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27). Depending on the patient cohort, several studies reported a stronger initial contraction (1,4,(23)(24)(25)27) of anti-COVID humoral responses.…”

Persistence of Anti-S Titre among Healthcare Workers Vaccinated with BNT162b2 mRNA COVID-19

“…Data from convalescent patients showed that neutralizing antibody levels decline over time, between one to four months after symptom onset [ 16 ]. Moreover, the duration of the humoral immune response to SARS-CoV-2 among non-vaccinated convalescent patients, analyzed for twelve months, showed that the anti-spike IgG decline was positively associated with peak antibody titre and age, and inversely associated with WHO severity score [ 17 ].…”