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1.
SSRN; 2022.
Preprint in English | SSRN | ID: ppcovidwho-332326

ABSTRACT

Background: Heterogeneity of the population in relation to infection, COVID-19 vaccination and host characteristics is likely reflected in the underlying SARS-CoV-2 antibody responses. Methods: We measured IgM, IgA and IgG levels against SARS-CoV-2 spike and nucleocapsid antigens in 1,076 adults of a cohort study in Catalonia between June-November 2020 and a second time between May-July 2021. Questionnaire data and electronic health records on vaccination and COVID-19 testing were available in both periods. Findings: Antibody seroreversion occurred in 35.8% of the 64 participants infected almost a year ago and non-vaccinated, and was related to asymptomatic infection, age above 60 years and smoking. Among vaccinated, 2.1% did not present antibodies at the time of testing. In previously infected individuals, vaccination boosted the immune response and there was a slight but statistically significant increase in responses after a 2nd compared to 1st dose. Infected vaccinated participants had superior antibody levels across time compared to naïve vaccinated people. mRNA vaccines and, particularly the Spikevax, induced higher antibodies after 1st and 2nd doses compared to Vaxzevria or Janssen COVID-19 vaccines. In multivariable regression analyses, antibody responses after vaccination were predicted by type of vaccine, infection age, sex, smoking, mental and cardiovascular diseases. Interpretation: Our data support that infected people would benefit from vaccination. Results also indicate that hybrid immunity results in superior antibody responses and infection-naïve people would need a booster dose earlier than previously infected people. Mental diseases are associated with less efficient response to vaccination.

2.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-309589

ABSTRACT

We assessed the duration and baseline determinants of antibody responses to SARS-CoV-2 spike antigens and the occurrence of reinfections in a prospective cohort of 173 Spanish primary health care worker patients followed up initially for nine months and subsequently up to 12.5 months after COVID-19 symptoms onset. Seropositivity to SARS-CoV-2 spike and receptor binding domain antigens up to 149-270 days was 92.49% (90.17% IgG, 76.3% IgA, 60.69% IgM). In a subset of 64 health care workers who had not yet been vaccinated by April 2021, seropositivity was 96.88% (95.31% IgG, 82.81% IgA) up to 322-379 days post symptoms onset. There were four suspected reinfections detected by passive case detection, two among seronegative individuals (five and seven months after the first episode), and one low antibody responder. Antibody levels significantly correlated with fever, hospitalization, anosmia/hypogeusia, allergies, smoking and occupation. Stable sustainment of IgG responses raises hope for long-lasting COVID-19 vaccine immunity.

3.
Nat Commun ; 12(1): 4740, 2021 08 06.
Article in English | MEDLINE | ID: covidwho-1345557

ABSTRACT

Unraveling the long-term kinetics of antibodies to SARS-CoV-2 and the individual characteristics influencing it, including the impact of pre-existing antibodies to human coronaviruses causing common cold (HCoVs), is essential to understand protective immunity to COVID-19 and devise effective surveillance strategies. IgM, IgA and IgG levels against six SARS-CoV-2 antigens and the nucleocapsid antigen of the four HCoV (229E, NL63, OC43 and HKU1) were quantified by Luminex, and antibody neutralization capacity was assessed by flow cytometry, in a cohort of health care workers followed up to 7 months (N = 578). Seroprevalence increases over time from 13.5% (month 0) and 15.6% (month 1) to 16.4% (month 6). Levels of antibodies, including those with neutralizing capacity, are stable over time, except IgG to nucleocapsid antigen and IgM levels that wane. After the peak response, anti-spike antibody levels increase from ~150 days post-symptom onset in all individuals (73% for IgG), in the absence of any evidence of re-exposure. IgG and IgA to HCoV are significantly higher in asymptomatic than symptomatic seropositive individuals. Thus, pre-existing cross-reactive HCoVs antibodies could have a protective effect against SARS-CoV-2 infection and COVID-19 disease.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Coronavirus 229E, Human/immunology , Coronavirus NL63, Human/immunology , SARS-CoV-2/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antigens, Viral/immunology , COVID-19/immunology , COVID-19/prevention & control , Common Cold/immunology , Common Cold/virology , Cross Protection/immunology , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood
4.
BMC Med ; 19(1): 155, 2021 06 28.
Article in English | MEDLINE | ID: covidwho-1286823

ABSTRACT

We assessed the duration and baseline determinants of antibody responses to SARS-CoV-2 spike antigens and the occurrence of reinfections in a prospective cohort of 173 Spanish primary health care worker patients followed initially for 9 months and subsequently up to 12.5 months after COVID-19 symptoms onset. Seropositivity to SARS-CoV-2 spike and receptor-binding domain antigens up to 149-270 days was 92.49% (90.17% IgG, 76.3% IgA, 60.69% IgM). In a subset of 64 health care workers who had not yet been vaccinated by April 2021, seropositivity was 96.88% (95.31% IgG, 82.81% IgA) up to 322-379 days post symptoms onset. Four suspected reinfections were detected by passive case detection, two among seronegative individuals (5 and 7 months after the first episode), and one low antibody responder. Antibody levels significantly correlated with fever, hospitalization, anosmia/hypogeusia, allergies, smoking, and occupation. Stable sustainment of IgG responses raises hope for long-lasting COVID-19 vaccine immunity.


Subject(s)
COVID-19/epidemiology , Health Personnel/statistics & numerical data , Adult , Antibodies, Viral/blood , COVID-19/blood , COVID-19/virology , COVID-19 Vaccines/administration & dosage , Cohort Studies , Cross-Sectional Studies , Female , Humans , Middle Aged , Prospective Studies , Reinfection/blood , Reinfection/epidemiology , Reinfection/virology , SARS-CoV-2/isolation & purification , Seroepidemiologic Studies , Spain/epidemiology
5.
J Clin Microbiol ; 59(2)2021 01 21.
Article in English | MEDLINE | ID: covidwho-1041778

ABSTRACT

Reliable serological tests are required to determine the prevalence of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and to characterize immunity to the disease in order to address key knowledge gaps in the coronavirus disease 2019 (COVID-19) pandemic. Quantitative suspension array technology (qSAT) assays based on the xMAP Luminex platform overcome the limitations of rapid diagnostic tests and enzyme-linked immunosorbent assays (ELISAs) with their higher precision, dynamic range, throughput, miniaturization, cost-efficiency, and multiplexing capacity. We developed three qSAT assays for IgM, IgA, and IgG against a panel of eight SARS-CoV-2 antigens, including spike protein (S), nucleocapsid protein (N), and membrane protein (M) constructs. The assays were optimized to minimize the processing time and maximize the signal-to-noise ratio. We evaluated their performances using 128 prepandemic plasma samples (negative controls) and 104 plasma samples from individuals with SARS-CoV-2 diagnosis (positive controls), of whom 5 were asymptomatic, 51 had mild symptoms, and 48 were hospitalized. Preexisting IgG antibodies recognizing N, M, and S proteins were detected in negative controls, which is suggestive of cross-reactivity to common-cold coronaviruses. The best-performing antibody/antigen signatures had specificities of 100% and sensitivities of 95.78% at ≥14 days and 95.65% at ≥21 days since the onset of symptoms, with areas under the curve (AUCs) of 0.977 and 0.999, respectively. Combining multiple markers as assessed by qSAT assays has the highest efficiency, breadth, and versatility to accurately detect low-level antibody responses for obtaining reliable data on the prevalence of exposure to novel pathogens in a population. Our assays will allow gaining insights into antibody correlates of immunity and their kinetics, required for vaccine development to combat the COVID-19 pandemic.


Subject(s)
Antigens, Viral/immunology , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Immunoglobulin Isotypes/blood , SARS-CoV-2/immunology , Adult , Antibodies, Viral/blood , COVID-19/blood , Cross Reactions , Female , Humans , Immunoassay , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity , Viral Structural Proteins/immunology
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