Robust neutralizing antibodies to SARS-CoV-2 infection persist for months.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic with millions infected and more than 1 million fatalities. Questions regarding the robustness, functionality, and longevity of the antibody response to the virus remain unanswered. Here, on the basis of a dataset of 30,082 individuals screened at Mount Sinai Health System in New York City, we report that the vast majority of infected individuals with mild-to-moderate COVID-19 experience robust immunoglobulin G antibody responses against the viral spike protein. We also show that titers are relatively stable for at least a period of about 5 months and that anti-spike binding titers significantly correlate with neutralization of authentic SARS-CoV-2. Our data suggest that more than 90% of seroconverters make detectable neutralizing antibody responses. These titers remain relatively stable for several months after infection.

Mission, Organization, and Future Direction of the Serological Sciences Network for COVID-19 (SeroNet) Epidemiologic Cohort Studies.

Background: Global efforts are needed to elucidate the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the underlying cause of coronavirus disease 2019 (COVID-19), including seroprevalence, risk factors, and long-term sequelae, as well as immune responses after vaccination across populations and the social dimensions of prevention and treatment strategies. Methods: In the United States, the National Cancer Institute in partnership with the National Institute of Allergy and Infectious Diseases, established the SARS-CoV-2 Serological Sciences Network (SeroNet) as the nation's largest coordinated effort to study coronavirus disease 2019. The network comprises multidisciplinary researchers bridging gaps and fostering collaborations among immunologists, epidemiologists, virologists, clinicians and clinical laboratories, social and behavioral scientists, policymakers, data scientists, and community members. In total, 49 institutions form the SeroNet consortium to study individuals with cancer, autoimmune disease, inflammatory bowel diseases, cardiovascular diseases, human immunodeficiency virus, transplant recipients, as well as otherwise healthy pregnant women, children, college students, and high-risk occupational workers (including healthcare workers and first responders). Results: Several studies focus on underrepresented populations, including ethnic minorities and rural communities. To support integrative data analyses across SeroNet studies, efforts are underway to define common data elements for standardized serology measurements, cellular and molecular assays, self-reported data, treatment, and clinical outcomes. Conclusions: In this paper, we discuss the overarching framework for SeroNet epidemiology studies, critical research questions under investigation, and data accessibility for the worldwide scientific community. Lessons learned will help inform preparedness and responsiveness to future emerging diseases.

SARS-CoV-2 Antibody Response among Women Infected during Pregnancy.

OBJECTIVES: Novel coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) virus has been declared a pandemic by the World Health Organization as of March 11, 2020. Pregnant women naturally have a reduced immune system due to immunological changes and decreased lung capacity due to respiratory adaptations, making them more susceptible to coronavirus complications. Within the Mount Sinai Health system, more than 15,000 deliveries are performed annually. We began to care for pregnant women with known COVID-19 infections in late March of 2020. In early April 2020, a policy was implemented to perform universal COVID-19 testing for all women planning to deliver within the Mount Sinai Health system. We examined the antibody response of postpartum women who delivered at Mount Sinai Hospital with a SARS-CoV-2 infection between the study intervals during March 15, 2020, through April 30, 2020. STUDY DESIGN: This was a prospective observational study examining the immune response of pregnant women who delivered at Mount Sinai Hospital with a polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection. Women with a SARS-CoV-2 infection were contacted via phone to discuss participation in the study. Patients who consented were scheduled for a phlebotomy visit to assess their antibody titer levels to COVID-19. The COVID-19 enzyme-linked immunosorbent assay (ELISA) immunoglobulin (Ig)-G antibody test was used to evaluate the patients' antibody titers. The assay detects IgG antibodies for the detection of IgG seroconversion in patients following a known recent SARS-CoV-2 infection. RESULTS: A total of 120 patients were identified with a documented SARS-CoV-2 infection who delivered within the prespecified time frame. Of those patients, 25 women agreed to participate and were included. Of them, 64.00% were Caucasian with a mean age of 35 years. The mean body mass index (BMI) was 30 kg/m2 and the majority of patients had commercial insurance (88.00%). The majority of women were asymptomatic for COVID-19 at the time of admission (80.00%) and the average gestational age of delivery and diagnosis of COVID-19 was 39 weeks' gestation. The later the gestational age at the time of diagnosis, the lower the antibody titer response. When examining the interval from diagnosis to antibody titer analysis, patients with the highest titers (2,880) tended to have a shorter interval between their COVID-19 diagnosis and the time at which the titer level was drawn. Patients with symptoms on admission had similar antibody titer levels when compared with women who were asymptomatic. CONCLUSION: The antibody response among women infected with COVID-19 during pregnancy appears to be greater when the patients are diagnosed at an earlier gestational age. KEY POINTS: · COVID-19 antibody status appears to be greater when diagnosed at an earlier gestational age.. · Asymptomatic and symptomatic pregnant women had similar antibody responses.. · Patients with the highest titers tended to have a shorter interval between their COVID-19 diagnoses..

Humoral response and PCR positivity in patients with COVID-19 in the New York City region, USA: an observational study.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic. The proportion of infected individuals who seroconvert is still an open question. In addition, it has been shown in some individuals that viral genome can be detected up to 3 months after symptom resolution. We investigated both seroconversion and PCR positivity in a large cohort of convalescent serum donors in the New York City (NY, USA) region. METHODS: In this observational study, we ran an outreach programme in the New York City area. We recruited participants via the REDCap (Vanderbilt University, Nashville, TN, USA) online survey response. Individuals with confirmed or suspected SARS-CoV-2 infection were screened via PCR for presence of viral genome and via ELISA for presence of anti-SARS-CoV-2 spike antibodies. One-way ANOVA and Fisher's exact test were used to measure the association of age, gender, symptom duration, and days from symptom onset and resolution with positive antibody results. FINDINGS: Between March 26 and April 10, 2020, we measured SARS-CoV-2 antibody titres in 1343 people. Of the 624 participants with confirmed SARS-CoV-2 infection who had serologies done after 4 weeks, all but three seroconverted to the SARS-CoV-2 spike protein, whereas 269 (37%) of 719 participants with suspected SARS-CoV-2 infection seroconverted. PCR positivity was detected up to 28 days from symptom resolution. INTERPRETATION: Most patients with confirmed COVID-19 seroconvert, potentially providing immunity to reinfection. We also report that in a large proportion of individuals, viral genome can be detected via PCR in the upper respiratory tract for weeks after symptom resolution, but it is unclear whether this signal represents infectious virus. Analysis of our large cohort suggests that most patients with mild COVID-19 seroconvert 4 weeks after illness, and raises questions about the use of PCR to clear positive individuals. FUNDING: None.

COVID-19: Staging of a New Disease.

Coronavirus disease 2019 (COVID-19), like cancer, is a complex disease with clinical phases of progression. Initially conceptualized as a respiratory disease, COVID-19 is increasingly recognized as a multi-organ and heterogeneous illness. Disease staging is a method for measuring the progression and severity of an illness using objective clinical and molecular criteria. Integral to cancer staging is "metastasis," defined as the spread of a disease-producing agent, including neoplastic cells and pathogens such as certain viruses, from the primary site to distinct anatomic locations. Staging provides valuable frameworks and benchmarks for clinical decision-making in patient management, improved prognostication, and evidence-based treatment selection.

Neutralizing Antibody Responses in COVID-19 Convalescent Sera.

Passive transfer of antibodies from COVID-19 convalescent patients is being used as an experimental treatment for eligible patients with SARS-CoV-2 infections. The United States Food and Drug Administration's (FDA) guidelines for convalescent plasma initially recommended target antibody titers of 160. We evaluated SARS-CoV-2 neutralizing antibodies in sera from recovered COVID-19 patients using plaque reduction neutralization tests (PRNT) at moderate (PRNT50) and high (PRNT90) stringency thresholds. We found that neutralizing activity significantly increased with time post symptom onset (PSO), reaching a peak at 31-35 days PSO. At this point, the number of sera having neutralizing titers of at least 160 was approximately 93% (PRNT50) and approximately 54% (PRNT90). Sera with high SARS-CoV-2 antibody levels (>960 enzyme-linked immunosorbent assay titers) showed maximal activity, but not all high-titer sera contained neutralizing antibody at FDA recommended levels, particularly at high stringency. These results underscore the value of serum characterization for neutralization activity.

Convalescent plasma treatment of severe COVID-19: a propensity score-matched control study.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a new human disease with few effective treatments1. Convalescent plasma, donated by persons who have recovered from COVID-19, is the acellular component of blood that contains antibodies, including those that specifically recognize SARS-CoV-2. These antibodies, when transfused into patients infected with SARS-CoV-2, are thought to exert an antiviral effect, suppressing virus replication before patients have mounted their own humoral immune responses2,3. Virus-specific antibodies from recovered persons are often the first available therapy for an emerging infectious disease, a stopgap treatment while new antivirals and vaccines are being developed1,2. This retrospective, propensity score-matched case-control study assessed the effectiveness of convalescent plasma therapy in 39 patients with severe or life-threatening COVID-19 at The Mount Sinai Hospital in New York City. Oxygen requirements on day 14 after transfusion worsened in 17.9% of plasma recipients versus 28.2% of propensity score-matched controls who were hospitalized with COVID-19 (adjusted odds ratio (OR), 0.86; 95% confidence interval (CI), 0.75-0.98; chi-square test P value = 0.025). Survival also improved in plasma recipients (adjusted hazard ratio (HR), 0.34; 95% CI, 0.13-0.89; chi-square test P = 0.027). Convalescent plasma is potentially effective against COVID-19, but adequately powered, randomized controlled trials are needed.