Neutralizing antibody response to SARS-CoV-2 persists 9 months post symptom onset in mild and asymptomatic patients

Abstract

Objective A better understanding of immune response against SARS-CoV-2 infection is critical to predict its dynamics within general population and its impact on vaccination strategy. We assessed both neutralizing antibody (Nab) activity persistence and SARS-CoV-2 serology in serum samples of mild and asymptomatic patients nine months post symptom onset (PSO) in a primary care context among immunocompetent adults. Methods A longitudinal cohort of crewmembers (CM) exposed to COVID-19 during the SARS-CoV-2 outbreak on the French aircraft carrier in April 2020 was created. CM infected with COVID-19 and having a positive serology at the end of quarantine were tested at 9-months PSO. Samples were collected at 18 and 280-days PSO. For each patient, both serology and serum viral neutralizing activity were performed. Results We analyzed 86 CM. Samples were collected at 18 and 280-days PSO. The seroconversion rate was 100% and 93% (82/86) at 18 and 280 days, respectively, while 72.7% of patients exhibited Persistent Nab at 9 months, regardless of disease severity. Conclusion Nab persists up to 9 months following asymptomatic/mild COVID-19 among young adults regardless of serology results at that time.

High secondary attack rate and persistence of SARS-CoV-2 antibodies in household transmission study participants, Finland 2020–2021

“…This slightly higher rate of persistence is likely explained by differing study populations, as the previous study involved more people with severe COVID-19. Other studies using a live SARS-CoV-2 assay have reported measurable NAb in 73% ( 39 ) and 85% ( 40 ) of participants 9 months and a year after SARS-CoV-2 infection, respectively. Studies performed with a surrogate virus have reported neutralizing activity to persist e.g., 60% 9 months after infection ( 41 ) and in 58% ( 42 ) and 73% ( 43 ) of participants a year after infection.…”

Proper Selection of In Vitro Cell Model Affects the Characterization of the Neutralizing Antibody Response against SARS-CoV-2

“…This evaluation was performed not only on the gold standard model (Vero E6) but also on the other two characterized cell lines. The reference methods to assess the neutralizing activity of sera against SARS-CoV-2 infection are those relying on the CPE evaluation, which include the microneutralization assay [13,27,[31][32][33][34][35]. However, virus infection cannot be assessed through CPE evaluation in the Calu-3 model; therefore, the detection method had to be different.…”

Sustained but Declining Humoral Immunity Against SARS-CoV-2 at 9 Months Postvaccination With BNT162b2: A Prospective Evaluation in 309 Healthy Individuals

“…The kinetics of antibody response following mRNA‐based vaccine immunization are similar with the kinetics of antibodies against SARS‐CoV‐2 in convalescent persons. Anti‐SARS‐CoV‐2 S, S‐RBD, nucleocapsid (N), N‐RBD antibodies, and NAbs persist but decline in time up to 8 months post COVID‐19 onset 30–32 . Although more severe COVID‐19 cases may have a superior antibody response, humoral and cellular activity against SARS‐CoV‐2 remains evident even among asymptomatic and mild cases at 9 months postsymptom onset 30,31,33–35 .…”