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2.
Clin Transl Immunology ; 11(4): e1388, 2022.
Article in English | MEDLINE | ID: covidwho-1798516

ABSTRACT

Objective: To determine the long-term impact of prior SARS-CoV-2 infection on immune responses after COVID-19 vaccination. Methods: Using longitudinally collected blood samples from the COMMUNITY study, we determined binding (WHO BAU mL-1) and neutralising antibody titres against ten SARS-CoV-2 variants over 7 months following BNT162b2 in SARS-CoV-2-recovered (n = 118) and SARS-CoV-2-naïve (n = 289) healthcare workers with confirmed prior SARS-CoV-2 infection. A smaller group with (n = 47) and without (n = 60) confirmed prior SARS-CoV-2 infection receiving ChAdOx1 nCoV-19 was followed for 3 months. SARS-CoV-2-specific memory T-cell responses were investigated in a subset of SARS-CoV-2-naïve and SARS-CoV-2-recovered vaccinees. Results: Vaccination with both vaccine platforms resulted in substantially enhanced T-cell responses, anti-spike IgG responses and neutralising antibodies effective against ten SARS-CoV-2 variants in SARS-CoV-2-recovered participants as compared to SARS-CoV-2-naïve participants. The enhanced immune responses sustained over 7 months following vaccination. Conclusion: These findings imply that prior SARS-CoV-2 infection should be taken into consideration when planning booster doses and design of current and future COVID-19 vaccine programmes.

3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-332419

ABSTRACT

Background Booster vaccine doses offer protection against severe COVID-19 caused by omicron but are less effective against infection. Characteristics such as serological correlates of protection, viral abundance and clearance of omicron infections in triple vaccinated individuals are scarce. Methods We conducted a 4-week twice-weekly SARS-CoV-2 qPCR screening shortly after an mRNA vaccine booster in 375 healthcare workers. Anti-Spike IgG levels and neutralization titers were determined at study start. qPCR-positive participants were sampled repeatedly for two weeks and monitored for symptoms. Result In total 82 (cumulative incidence 22%) omicron infections were detected, divided between BA.1, BA.1.1 and BA.2. Only 10% of infected participants remained asymptomatic. Viral load peaked at day 3 and live virus could be detected for up to 9 days after first PCR-positive sample. Presence of symptoms correlated to elevated viral load (p<0.0001), but despite resolution of symptoms most participants showed Ct levels <30 at day 9. While post-booster antibody titers were similar in those with and without subsequent breakthrough infection (p>0.05), high antibody titers were linked to reduced viral load (p<0.01) and time to viral clearance (p<0.01). No significant differences were observed for viral load and time to viral clearance between BA.1, BA.1.1 and BA.2 infected individuals. Conclusion We report high incidence of omicron infections despite recent booster vaccination in triple vaccinated individuals. Vaccine-induced antibody titres seem to play a limited role in risk of omicron infection. High viral load and secretion of live virus for up to nine days may increase transmission in a triple vaccinated population.

4.
Immun Inflamm Dis ; 10(4): e595, 2022 04.
Article in English | MEDLINE | ID: covidwho-1739165

ABSTRACT

BACKGROUND: Cellular immune memory responses post coronavirus disease 2019 (COVID-19) have been difficult to assess due to the risks of contaminating the immune response readout with memory responses stemming from previous exposure to endemic coronaviruses. The work herein presents a large-scale long-term follow-up study investigating the correlation between symptomology and cellular immune responses four to five months post seroconversion based on a unique severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific peptide pool that contains no overlapping peptides with endemic human coronaviruses. METHODS: Peptide stimulated memory T cell responses were assessed with dual interferon-gamma (IFNγ) and interleukin (IL)-2 Fluorospot. Serological analyses were performed using a multiplex antigen bead array. RESULTS: Our work demonstrates that long-term SARS-CoV-2-specific memory T cell responses feature dual IFNγ and IL-2 responses, whereas cross-reactive memory T cell responses primarily generate IFNγ in response to SARS-CoV-2 peptide stimulation. T cell responses correlated to long-term humoral immune responses. Disease severity as well as specific COVID-19 symptoms correlated with the magnitude of the SARS-CoV-2-specific memory T cell response four to five months post seroconversion. CONCLUSION: Using a large cohort and a SARS-CoV-2-specific peptide pool we were able to substantiate that initial disease severity and symptoms correlate with the magnitude of the SARS-CoV-2-specific memory T cell responses.


Subject(s)
COVID-19 , SARS-CoV-2 , CD4-Positive T-Lymphocytes , Follow-Up Studies , Humans , Immunity, Cellular , Severity of Illness Index
5.
Vaccines (Basel) ; 10(3)2022 Feb 24.
Article in English | MEDLINE | ID: covidwho-1726057

ABSTRACT

Heterologous primary immunization against SARS-CoV-2 is part of applied recommendations. However, little is known about duration of immune responses after heterologous vaccine regimens. To evaluate duration of immune responses after primary vaccination with homologous adeno-vectored ChAdOx1 nCoV-19 vaccine (ChAd) or heterologous ChAd/BNT162b2 mRNA vaccine (BNT), anti-spike-IgG and SARS-CoV-2 VOC-neutralizing antibody responses were measured in 354 healthcare workers (HCW) at 2 weeks, 3 months, 5 months and 6 months after the second vaccine dose. T-cell responses were investigated using a whole blood interferon gamma (IFN-γ) release assay 2 weeks and 3 months post second vaccine dose. Two hundred and ten HCW immunized with homologous BNT were enrolled for comparison of antibody responses. In study participants naïve to SARS-CoV-2 prior to vaccination, heterologous ChAd/BNT resulted in 6-fold higher peak anti-spike IgG antibody titers compared to homologous ChAd vaccination. The half-life of antibody titers was 3.1 months (95% CI 2.8-3.6) following homologous ChAd vaccination and 1.9 months (95% CI 1.7-2.1) after heterologous vaccination, reducing the GMT difference between the groups to 3-fold 6 months post vaccination. Peak T-cell responses were stronger in ChAd/BNT vaccinees, but no significant difference was observed 3 months post vaccination. SARS-CoV-2 infection prior to vaccination resulted in substantially higher peak GMTs and IFN-γ levels and enhanced SARS-CoV-2 specific antibody and T cell responses over time. Heterologous primary SARS-CoV-2 immunization with ChAd and BNT elicits a stronger initial immune response compared to homologous vaccination with ChAd. However, although the differences in humoral responses remain over 6 months, the difference in SARS-CoV-2 specific T cell responses are no longer significant three months after vaccination.

6.
Med (N Y) ; 3(2): 137-153.e3, 2022 Feb 11.
Article in English | MEDLINE | ID: covidwho-1705838

ABSTRACT

BACKGROUND: Immunocompromised individuals are highly susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Whether vaccine-induced immunity in these individuals involves oral cavity, a primary site of infection, is presently unknown. METHODS: Immunocompromised patients (n = 404) and healthy controls (n = 82) participated in a prospective clinical trial (NCT04780659) encompassing two doses of the mRNA BNT162b2 vaccine. Primary immunodeficiency (PID), secondary immunodeficiencies caused by human immunodeficiency virus (HIV) infection, allogeneic hematopoietic stem cell transplantation (HSCT)/chimeric antigen receptor T cell therapy (CAR-T), solid organ transplantation (SOT), and chronic lymphocytic leukemia (CLL) patients were included. Salivary and serum immunoglobulin G (IgG) reactivities to SARS-CoV-2 spike were measured by multiplex bead-based assays and Elecsys anti-SARS-CoV-2 S assay. FINDINGS: IgG responses to SARS-CoV-2 spike antigens in saliva in HIV and HSCT/CAR-T groups were comparable to those of healthy controls after vaccination. The PID, SOT, and CLL patients had weaker responses, influenced mainly by disease parameters or immunosuppressants. Salivary responses correlated remarkably well with specific IgG titers and the neutralizing capacity in serum. Receiver operating characteristic curve analysis for the predictive power of salivary IgG yielded area under the curve (AUC) = 0.95 and positive predictive value (PPV) = 90.7% for the entire cohort after vaccination. CONCLUSIONS: Saliva conveys vaccine responses induced by mRNA BNT162b2. The predictive power of salivary spike IgG makes it highly suitable for screening vulnerable groups for revaccination. FUNDING: Knut and Alice Wallenberg Foundation, Erling Perssons family foundation, Region Stockholm, Swedish Research Council, Karolinska Institutet, Swedish Blood Cancer Foundation, PID patient organization of Sweden, Nordstjernan AB, Center for Medical Innovation (CIMED), Swedish Medical Research Council, and Stockholm County Council (ALF).


Subject(s)
COVID-19 , Leukemia, Lymphocytic, Chronic, B-Cell , Antibodies, Viral , COVID-19/prevention & control , Humans , Immunocompromised Host , Immunoglobulin A, Secretory , Immunoglobulin G , Prospective Studies , RNA, Messenger , SARS-CoV-2 , Saliva , Seroconversion , Spike Glycoprotein, Coronavirus
7.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-312455

ABSTRACT

B-cell depleting therapies are widely used as immunomodulating agents for autoimmune diseases such as multiple sclerosis. The possible impact of B-cell depletion on development of humoral and cellular immunity to viruses and specifically SARS-CoV-2 has raised concerns with the COVID-19 pandemic. We here determined humoral and cellular responses in participants of an observational trial comprising several multiple sclerosis disease modulatory drugs (COMBAT-MS;NCT03193866). Patients on B-cell depleting treatment, who previously had COVID-19-like symptoms, developed anti-SARS-CoV-2 antibodies and/or T-cell memory irrespective of their B-cell depletion status. Furthermore, antibody titers were similar to those observed with other treatments or controls, and anti-SARS-CoV-2 T-cells displayed functional similarity to controls producing IFN-γ and TNF. These results inform on the role of B- and T-cells in SARS-CoV-2 immunity and provide evidence that B-cell depleting therapy does not substantially abrogate SARS-CoV-2 immunological memory, in turn suggesting a low risk for reinfection and potentially responsiveness to vaccination.Funding: The COMBAT-MS study is funded through a Patient-Centered Outcomes Research Institute (PCORI) Award (MS-1511-33196), modified to include the sub-study reported herein. Additional funding was obtained from the Swedish Medical Research council (grant no. 2017-03054), Swedish Brain Foundation, NEURO Sweden, Tetra Laval, Region Stockholm, Knut and Alice Wallenberg foundation, Erling-Persson family foundation and Petrus och Augusta Hedlunds Stiftelse.Conflict of Interest: Tomas Olsson has received unrestricted grants for extended multiplesclerosis studies in relation to COVID-19 from Biogen and Merck. Not related to this manuscript, T. O. has received unrestricted grants, advisory board/ lectures from Biogen, Merck, Novartis, and Sanofi and F. P. has received research grants from Genzyme, Merck KGaA and UCB, and fees for serving as Chair of DMC in clinical trials with Parexel. All other authors declare no competing interests.Ethical Approval: Study procedures were conducted under the following ethical permits approved by the Swedish ethical review authority;COMBAT-MS: 2017/32-31/4;STOPMSII: 2009/2107-31/2;2020 00052, with written informed consent from participants.

8.
Scand J Public Health ; 49(7): 707-712, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1634116

ABSTRACT

AIM: We aimed to assess prevalence of IgG antibodies to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and factors associated with seropositivity in a large cohort of healthcare workers (HCWs). METHODS: From 11 May until 11 June 2020, 3981 HCWs at a large Swedish emergency care hospital provided serum samples and questionnaire data. Presence of IgG antibodies to SARS-CoV-2 was measured as an indicator of SARS-CoV-2 exposure. RESULTS: The total seroprevalence was 18% and increased during the study period. Among the seropositive HCWs, 11% had been entirely asymptomatic. Participants who worked with COVID-19 patients had higher odds for seropositivity: adjusted odds ratio 1.96 (95% confidence intervals 1.59-2.42). HCWs from three of the departments managing COVID-19 patients had significantly higher seroprevalences, whereas the prevalence among HCWs from the intensive care unit (also managing COVID-19 patients) was significantly lower. CONCLUSIONS: HCWs in contact with SARS-CoV-2 infected patients had a variable, but on average higher, likelihood for SARS-CoV-2 infections.


Subject(s)
COVID-19 , SARS-CoV-2 , Health Personnel , Hospitals , Humans , Personnel, Hospital , Seroepidemiologic Studies
9.
PLoS One ; 17(1): e0262169, 2022.
Article in English | MEDLINE | ID: covidwho-1633137

ABSTRACT

Current SARS-CoV-2 serological assays generate discrepant results, and the longitudinal characteristics of antibodies targeting various antigens after asymptomatic to mild COVID-19 are yet to be established. This longitudinal cohort study including 1965 healthcare workers, of which 381 participants exhibited antibodies against the SARS-CoV-2 spike antigen at study inclusion, reveal that these antibodies remain detectable in most participants, 96%, at least four months post infection, despite having had no or mild symptoms. Virus neutralization capacity was confirmed by microneutralization assay in 91% of study participants at least four months post infection. Contrary to antibodies targeting the spike protein, antibodies against the nucleocapsid protein were only detected in 80% of previously anti-nucleocapsid IgG positive healthcare workers. Both anti-spike and anti-nucleocapsid IgG levels were significantly higher in previously hospitalized COVID-19 patients four months post infection than in healthcare workers four months post infection (p = 2*10-23 and 2*10-13 respectively). Although the magnitude of humoral response was associated with disease severity, our findings support a durable and functional humoral response after SARS-CoV-2 infection even after no or mild symptoms. We further demonstrate differences in antibody kinetics depending on the antigen, arguing against the use of the nucleocapsid protein as target antigen in population-based SARS-CoV-2 serological surveys.


Subject(s)
COVID-19/pathology , Immunity, Humoral , Adult , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Asymptomatic Infections/epidemiology , COVID-19/immunology , COVID-19/virology , Female , Health Personnel , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Longitudinal Studies , Male , Middle Aged , Nucleocapsid/immunology , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Severity of Illness Index , Spike Glycoprotein, Coronavirus/immunology
10.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-294908

ABSTRACT

People with previous SARS-CoV-2 infection mount potent immune responses to COVID-19 vaccination, but long-term effects of prior infection on these immune responses are unknown. We investigated the long-term impact of prior SARS-CoV-2 infection on humoral and cellular immune responses in healthcare workers receiving the mRNA BNT162b2 or the adenovirus vectored ChAdOx1 nCoV-19 vaccine. Vaccination with both vaccine platforms resulted in substantially enhanced T cell immune responses, antibody responses to spike and neutralizing antibodies effective against ten SARS-CoV-2 variants following SARS-CoV-2 infection, compared to in naïve individuals. The enhanced immune responses sustained over seven months following vaccination. These findings imply that prior infection should be taken into consideration when planning booster doses and design of current and future COVID-19 vaccine programs. One-Sentence Summary SARS-CoV-2 infection prior to vaccination leads to substantial and durable increases in immune memory responses.

11.
EBioMedicine ; 74: 103705, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1540597

ABSTRACT

BACKGROUND: Patients with immunocompromised disorders have mainly been excluded from clinical trials of vaccination against COVID-19. Thus, the aim of this prospective clinical trial was to investigate safety and efficacy of BNT162b2 mRNA vaccination in five selected groups of immunocompromised patients and healthy controls. METHODS: 539 study subjects (449 patients and 90 controls) were included. The patients had either primary (n=90), or secondary immunodeficiency disorders due to human immunodeficiency virus infection (n=90), allogeneic hematopoietic stem cell transplantation/CAR T cell therapy (n=90), solid organ transplantation (SOT) (n=89), or chronic lymphocytic leukemia (CLL) (n=90). The primary endpoint was seroconversion rate two weeks after the second dose. The secondary endpoints were safety and documented SARS-CoV-2 infection. FINDINGS: Adverse events were generally mild, but one case of fatal suspected unexpected serious adverse reaction occurred. 72.2% of the immunocompromised patients seroconverted compared to 100% of the controls (p=0.004). Lowest seroconversion rates were found in the SOT (43.4%) and CLL (63.3%) patient groups with observed negative impact of treatment with mycophenolate mofetil and ibrutinib, respectively. INTERPRETATION: The results showed that the mRNA BNT162b2 vaccine was safe in immunocompromised patients. Rate of seroconversion was substantially lower than in healthy controls, with a wide range of rates and antibody titres among predefined patient groups and subgroups. This clinical trial highlights the need for additional vaccine doses in certain immunocompromised patient groups to improve immunity. FUNDING: Knut and Alice Wallenberg Foundation, the Swedish Research Council, Nordstjernan AB, Region Stockholm, Karolinska Institutet, and organizations for PID/CLL-patients in Sweden.


Subject(s)
/adverse effects , Immunocompromised Host/immunology , Immunogenicity, Vaccine/immunology , SARS-CoV-2/immunology , Adenine/adverse effects , Adenine/analogs & derivatives , Adenine/therapeutic use , Antibodies, Viral/blood , COVID-19/prevention & control , Female , Hematopoietic Stem Cell Transplantation , Humans , Immunotherapy, Adoptive , Leukemia, Lymphocytic, Chronic, B-Cell , Male , Middle Aged , Mycophenolic Acid/adverse effects , Mycophenolic Acid/therapeutic use , Organ Transplantation , Piperidines/adverse effects , Piperidines/therapeutic use , Primary Immunodeficiency Diseases/immunology , Prospective Studies , Seroconversion , Spike Glycoprotein, Coronavirus/immunology , Vaccination/adverse effects
12.
N Biotechnol ; 66: 46-52, 2022 Jan 25.
Article in English | MEDLINE | ID: covidwho-1458735

ABSTRACT

Highly accurate serological tests are key to assessing the prevalence of SARS-CoV-2 antibodies and the level of immunity in the population. This is important to predict the current and future status of the pandemic. With the recent emergence of new and more infectious SARS-CoV-2 variants, assays allowing for high throughput analysis of antibodies able to neutralize SARS-CoV-2 become even more important. Here, we report the development and validation of a robust, high throughput method, which enables the assessment of antibodies inhibiting the binding between the SARS-CoV-2 spike protein and angiotensin converting enzyme 2 (ACE2). The assay uses recombinantly produced spike-f and ACE2 and is performed in a bead array format, which allows analysis of up to 384 samples in parallel per instrument over seven hours, demanding only one hour of manual handling. The method is compared to a microneutralization assay utilising live SARS-CoV-2 and is shown to deliver highly correlating data. Further, a comparison with a serological method that measures all antibodies recognizing the spike protein shows that this type of assessment provides important insights into the neutralizing efficiency of the antibodies, especially for individuals with low antibody levels. This method can be an important and valuable tool for large-scale assessment of antibody-based neutralization, including neutralization of new spike variants that might emerge.


Subject(s)
Antibodies, Neutralizing/isolation & purification , Antibodies, Viral/isolation & purification , COVID-19 , SARS-CoV-2 , Angiotensin-Converting Enzyme 2/immunology , COVID-19/immunology , High-Throughput Screening Assays , Humans , Neutralization Tests , Spike Glycoprotein, Coronavirus/immunology
13.
PLoS One ; 16(9): e0258041, 2021.
Article in English | MEDLINE | ID: covidwho-1443855

ABSTRACT

Numerous assays evaluating serological and cellular responses have been developed to characterize immune responses against SARS-CoV-2. Serological assays are both cost- and time-effective compared to cellular assays, but cellular immune responses may provide a diagnostic value to determine previous SARS-CoV-2 infection in seronegative individuals. However, potential cross-reactive T cell responses stemming from prior encounters with human coronaviruses (HCoVs) may affect assay specificity. In this study, we evaluated the specificity and sensitivity of a SARS-CoV-2 IFN-γ Release Assay (IGRA) based on the FluoroSpot method employing commercially available SARS-CoV-2-specific peptide pools, as well as an in-house designed SARS-CoV-2 peptide pool restricted to 5 amino acid stretches or less aligning with endemic HCoVs. Blood samples were obtained from healthcare workers (HCW) 5-6 months post SARS-CoV-2 spike (S) IgG and nucleocapsid (N) IgG dual seroconversion (n = 187) and HCW who had been S IgG and N IgG dual seronegative at repeated occasions, including the current sampling time point (n = 102). In addition, samples were obtained 4 to 5 months post infection from 55 polymerase chain reaction (PCR)-confirmed COVID-19 patients. Assay specificity and sensitivity were calculated with serology as a reference standard for HCW. The in-house generated peptide pool displayed a specificity of 96.1%, while the commercially available peptide pools displayed specificities of 80.4% and 85.3%, respectively. Sensitivity was higher in a cohort of previously hospitalized COVID-19 patients (96.4% and 84.0% for the commercially available peptide pools and 92.7% for the in-house generated peptide pool) compared to the HCW cohort (92.0% and 66.8% for the commercially available peptide pools and 76.0% for the in-house generated peptide pool). Based on these findings, the individual diagnostic value of T cell immune responses against SARS-CoV-2 currently appears to be limited but remain an important research tool ahead.


Subject(s)
COVID-19 Testing/methods , COVID-19/immunology , Immunity, Cellular , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/diagnosis , Health Personnel , Humans , Interferon-gamma/blood , Interferon-gamma/immunology , Sensitivity and Specificity , Seroconversion
14.
J Intern Med ; 291(1): 72-80, 2022 01.
Article in English | MEDLINE | ID: covidwho-1443300

ABSTRACT

BACKGROUND: Emerging data support detectable immune responses for months after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and vaccination, but it is not yet established to what degree and for how long protection against reinfection lasts. METHODS: We investigated SARS-CoV-2-specific humoral and cellular immune responses more than 8 months post-asymptomatic, mild and severe infection in a cohort of 1884 healthcare workers (HCW) and 51 hospitalized COVID-19 patients. Possible protection against SARS-CoV-2 reinfection was analyzed by a weekly 3-month polymerase chain reaction (PCR) screening of 252 HCW that had seroconverted 7 months prior to start of screening and 48 HCW that had remained seronegative at multiple time points. RESULTS: All COVID-19 patients and 96% (355/370) of HCW who were anti-spike IgG positive at inclusion remained anti-spike IgG positive at the 8-month follow-up. Circulating SARS-CoV-2-specific memory T cell responses were detected in 88% (45/51) of COVID-19 patients and in 63% (233/370) of seropositive HCW. The cumulative incidence of PCR-confirmed SARS-CoV-2 infection was 1% (3/252) among anti-spike IgG positive HCW (0.13 cases per 100 weeks at risk) compared to 23% (11/48) among anti-spike IgG negative HCW (2.78 cases per 100 weeks at risk), resulting in a protective effect of 95.2% (95% CI 81.9%-99.1%). CONCLUSIONS: The vast majority of anti-spike IgG positive individuals remain anti-spike IgG positive for at least 8 months regardless of initial COVID-19 disease severity. The presence of anti-spike IgG antibodies is associated with a substantially reduced risk of reinfection up to 9 months following asymptomatic to mild COVID-19.


Subject(s)
Antibodies, Viral/blood , COVID-19/diagnosis , COVID-19/immunology , Immunity, Cellular , Immunity, Humoral , Immunoglobulin G/immunology , Reinfection , Adult , Antibodies, Viral/immunology , Asymptomatic Infections , COVID-19 Nucleic Acid Testing , COVID-19 Serological Testing , Female , Humans , Immunoglobulin G/blood , Male , Middle Aged , Pandemics , SARS-CoV-2 , Time Factors
15.
Leukemia ; 36(2): 476-481, 2022 02.
Article in English | MEDLINE | ID: covidwho-1437661

ABSTRACT

We studied clinical and immunological outcome of Covid-19 in consecutive CLL patients from a well-defined area during month 1-13 of the pandemic. Sixty patients (median age 71 y, range 43-97) were identified. Median CIRS was eight (4-20). Patients had indolent CLL (n = 38), had completed (n = 12) or ongoing therapy (n = 10). Forty-six patients (77%) were hospitalized due to severe Covid-19 and 11 were admitted to ICU. Severe Covid-19 was equally distributed across subgroups irrespective of age, gender, BMI, CLL status except CIRS (p < 0.05). Fourteen patients (23%) died; age ≥75 y was the only significant risk factor (p < 0.05, multivariate analysis with limited power). Comparing month 1-6 vs 7-13 of the pandemic, deaths were numerically reduced from 32% to 18%, ICU admission from 37% to 15% whereas hospitalizations remained frequent (86% vs 71%). Seroconversion occurred in 33/40 patients (82%) and anti-SARS-CoV-2 antibodies were detectable at six and 12 months in 17/22 and 8/11 patients, respectively. Most (13/17) had neutralizing antibodies and 19/28 had antibodies in saliva. SARS-CoV-2-specific T-cells (ELISpot) were detected in 14/17 patients. Covid-19 continued to result in high admission even among consecutive and young early- stage CLL patients. A robust and durable B and/or T cell immunity was observed in most convalescents.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , B-Lymphocytes/immunology , COVID-19/complications , Leukemia, Lymphocytic, Chronic, B-Cell/immunology , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Adult , Aged , Aged, 80 and over , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/immunology , COVID-19/transmission , COVID-19/virology , Combined Modality Therapy , Female , Follow-Up Studies , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/therapy , Leukemia, Lymphocytic, Chronic, B-Cell/virology , Male , Middle Aged , Prognosis , SARS-CoV-2/isolation & purification
16.
iScience ; 24(9): 103078, 2021 Sep 24.
Article in English | MEDLINE | ID: covidwho-1385759

ABSTRACT

B cell depleting therapies (BCDTs) are widely used as immunomodulating agents for autoimmune diseases such as multiple sclerosis. Their possible impact on development of immunity to severe acute respiratory syndrome virus-2 (SARS-CoV-2) has raised concerns with the coronavirus disease 2019 (COVID-19) pandemic. We here evaluated the frequency of COVID-19-like symptoms and determined immunological responses in participants of an observational trial comprising several multiple sclerosis disease modulatory drugs (COMBAT-MS; NCT03193866) and in eleven patients after vaccination, with a focus on BCDT. Almost all seropositive and 17.9% of seronegative patients on BCDT, enriched for a history of COVID-19-like symptoms, developed anti-SARS-CoV-2 T cell memory, and T cells displayed functional similarity to controls producing IFN-γ and TNF. Following vaccination, vaccine-specific humoral memory was impaired, while all patients developed a specific T cell response. These results indicate that BCDTs do not abrogate SARS-CoV-2 cellular memory and provide a possible explanation as to why the majority of patients on BCDTs recover from COVID-19.

17.
Prev Med Rep ; 24: 101518, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1364408

ABSTRACT

Healthcare workers (HCWs) are a risk group for SARS-CoV-2 infection, but which healthcare work that conveys risk and to what extent such risk can be prevented is not clear. Starting on April 24th, 2020, all employees at work (n = 15,300) at the Karolinska University Hospital, Stockholm, Sweden were invited and 92% consented to participate in a SARS-CoV-2 cohort study. Complete SARS-CoV-2 serology was available for n = 12,928 employees and seroprevalences were analyzed by age, sex, profession, patient contact, and hospital department. Relative risks were estimated to examine the association between type of hospital department as a proxy for different working environment exposure and risk for seropositivity, adjusting for age, sex, sampling week, and profession. Wards that were primarily responsible for COVID-19 patients were at increased risk (adjusted OR 1.95 (95% CI 1.65-2.32) with the notable exception of the infectious diseases and intensive care units (adjusted OR 0.86 (95% CI 0.66-1.13)), that were not at increased risk despite being highly exposed. Several units with similar types of work varied greatly in seroprevalences. Among the professions examined, nurse assistants had the highest risk (adjusted OR 1.62 (95% CI 1.38-1.90)). Although healthcare workers, in particular nurse assistants, who attend to COVID-19 patients are a risk group for SARS-CoV-2 infection, several units caring for COVID-19 patients had no excess risk. Large variations in seroprevalences among similar units suggest that healthcare work-related risk of SARS-CoV-2 infection may be preventable.

18.
EBioMedicine ; 70: 103523, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1356201

ABSTRACT

BACKGROUND: Recent reports demonstrate robust serological responses to a single dose of messenger RNA (mRNA) vaccines in individuals previously infected with SARS-CoV-2. Data on immune responses following a single-dose adenovirus-vectored vaccine expressing the SARS-CoV-2 spike protein (ChAdOx1 nCoV-19) in individuals with previous SARS-CoV-2 infection are however limited, and current guidelines recommend a two-dose regimen regardless of preexisting immunity. METHODS: We compared RBD-specific IgG and RBD-ACE2 blocking antibodies against SARS-CoV-2 wild type and variants of concern following two doses of the mRNA vaccine BNT162b2 in SARS-CoV-2 naïve healthcare workers (n=65) and a single dose of the adenovector vaccine ChAdOx1 nCoV-19 in 82 healthcare workers more than (n=45) and less than (n=37) 11 months post mild SARS-CoV-2 infection at time of vaccination. FINDINGS: The post-vaccine levels of RBD-specific IgG and neutralizing antibodies against the SARS-CoV-2 wild type and variants of concern including Delta lineage 1.617.2 were similar or higher in participants receiving a single dose of ChAdOx1 nCoV-19 vaccine post SARS-CoV-2 infection (both more than and less than 11 months post infection) compared to SARS-CoV-2 naïve participants who received two doses of BNT162b2 vaccine. INTERPRETATION: Our data support that a single dose ChAdOx1 nCoV-19 vaccine that is administered up to at least 11 months post SARS-CoV-2 infection serves as an effective immune booster. This provides a possible rationale for a single-dose vaccine regimen. FUNDING: A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.


Subject(s)
Antibodies, Neutralizing/immunology , Antibody Formation/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Female , Health Personnel , Humans , Immunization, Secondary/methods , Immunoglobulin G/immunology , Male , Middle Aged , Spike Glycoprotein, Coronavirus/immunology , Vaccination/methods
19.
Clin Transl Immunology ; 10(7): e1312, 2021.
Article in English | MEDLINE | ID: covidwho-1321684

ABSTRACT

OBJECTIVE: The COVID-19 pandemic poses an immense need for accurate, sensitive and high-throughput clinical tests, and serological assays are needed for both overarching epidemiological studies and evaluating vaccines. Here, we present the development and validation of a high-throughput multiplex bead-based serological assay. METHODS: More than 100 representations of SARS-CoV-2 proteins were included for initial evaluation, including antigens produced in bacterial and mammalian hosts as well as synthetic peptides. The five best-performing antigens, three representing the spike glycoprotein and two representing the nucleocapsid protein, were further evaluated for detection of IgG antibodies in samples from 331 COVID-19 patients and convalescents, and in 2090 negative controls sampled before 2020. RESULTS: Three antigens were finally selected, represented by a soluble trimeric form and the S1-domain of the spike glycoprotein as well as by the C-terminal domain of the nucleocapsid. The sensitivity for these three antigens individually was found to be 99.7%, 99.1% and 99.7%, and the specificity was found to be 98.1%, 98.7% and 95.7%. The best assay performance was although achieved when utilising two antigens in combination, enabling a sensitivity of up to 99.7% combined with a specificity of 100%. Requiring any two of the three antigens resulted in a sensitivity of 99.7% and a specificity of 99.4%. CONCLUSION: These observations demonstrate that a serological test based on a combination of several SARS-CoV-2 antigens enables a highly specific and sensitive multiplex serological COVID-19 assay.

20.
J Infect Dis ; 224(1): 14-20, 2021 07 02.
Article in English | MEDLINE | ID: covidwho-1294728

ABSTRACT

BACKGROUND: Whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positivity among asymptomatic subjects reflects past or future disease may be difficult to ascertain. METHODS: We tested 9449 employees at Karolinska University Hospital, Stockholm, Sweden for SARS-CoV-2 RNA and antibodies, linked the results to sick leave records, and determined associations with past or future sick leave using multinomial logistic regression. RESULTS: Subjects with high amounts of SARS-CoV-2 virus, indicated by polymerase chain reaction (PCR) cycle threshold (Ct) value, had the highest risk for sick leave in the 2 weeks after testing (odds ratio [OR], 11.97; 95% confidence interval [CI], 6.29-22.80) whereas subjects with low amounts of virus had the highest risk for sick leave in the 3 weeks before testing (OR, 6.31; 95% CI, 4.38-9.08). Only 2.5% of employees were SARS-CoV-2 positive while 10.5% were positive by serology and 1.2% were positive in both tests. Serology-positive subjects were not at excess risk for future sick leave (OR, 1.06; 95% CI, .71-1.57). CONCLUSIONS: High amounts of SARS-CoV-2 virus, as determined using PCR Ct values, was associated with development of sickness in the next few weeks. Results support the concept that PCR Ct may be informative when testing for SARS-CoV-2. Clinical Trials Registration. NCT04411576.


Subject(s)
Asymptomatic Diseases , COVID-19/epidemiology , COVID-19/virology , Health Personnel , SARS-CoV-2 , Adult , Aged , Antibodies, Viral , COVID-19/diagnosis , Disease Progression , Female , Hospitals, University , Humans , Male , Mass Screening , Middle Aged , Polymerase Chain Reaction , RNA, Viral , SARS-CoV-2/genetics , Serologic Tests , Sick Leave/statistics & numerical data , Sweden/epidemiology , Young Adult
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