Glucocorticoids selectively affect the memory T cell response to SARS-Cov2 spike in vaccinated and post-infected patients with systemic lupus erythematosus.

Immune response to vaccines and pathogens remains unclear in patients with systemic lupus erythematosus (SLE). To investigate this, a single-center retrospective study was conducted with 47 SLE patients vaccinated against COVID-19, including 13 who subsequently developed an asymptomatic/mild disease. As compared to controls, post-vaccine response against Spike was reduced in SLE patients when considering both memory T-cells in a whole blood interferon gamma release assay (IGRA-S) and IgG anti-Spike antibody (Ab) responses. The SLE-associated defective IGRA-S response was associated with a serum albumin level below 40 g/L and with the use of glucocorticoids, while a defective IgG anti-Spike Ab response was associated with lower levels of anti-dsDNA and anti-SSA/Ro 52 kDa Abs. IGRA-S and IgG anti-Spike responses were independent from SLE activity and clinical phenotype, low complement, hypergammaglobulinemia, and lymphopenia. As compared to controls, SLE patients showed a rapid decay of anti-Spike T-cell memory and stable IgG anti-Spike Ab responses. In conclusion, both T cell and humoral anti-Spike responses were independently affected in our SLE patients cohort, which supports the exploration of both responses in the follow-up of SLE patients and especially in those receiving glucocorticoids.

The influence of the nasopharyngeal viral load on the spread of the Omicron BA.2 variant.

We used variant typing PCR to describe the evolution of SARS-CoV-2 Omicron sublineages between December 2021 and mid-March 2022. The selective advantage of the BA.2 variant over BA.1 is not due to greater nasopharyngeal viral loads.

Glucocorticoid use as a cause of non-cellular immune response to SARS-Cov2 Spike in patients with immune system diseases.

Disease modifying therapies compromise immune response to SARS-Cov2 or its vaccine in patients with immune system diseases (ISD). Therefore, analysis of the humoral and cellular responses against Spike is of utmost importance to manage ISD patients. A single-center retrospective study was conducted to evaluate the impact of COVID-19 immunization in 87 ISD patients and 81 healthy controls. We performed a whole blood interferon gamma release assay using SARS-Cov2 Spike and Nucleocapsid recombinant proteins in order to evaluate T-cell memory response, and an IgG anti-Spike ELISA to evaluate humoral response. Cellular (26.4%) and humoral (44.8%) responses were negative against Spike in ISD patients following COVID-19 immunization. In univariate analysis, an anti-Spike T cell defective response was associated with the use of glucocorticoids (Odds ratio [OR] = 10.0; p < 10-4), serum albumin level ≤40 g/L (OR = 18.9; p < 10-4), age over 55 years old (OR = 3.9, p = 0.009) and ≤2 vaccine injections (OR = 4.9; p = 0.001). The impact of glucocorticoids persisted after adjustment for age and number of vaccine injections (OR = 8.38, p < 0.001). In contrast, the humoral response was impacted by the use of anti-CD20 mAb (OR = 24.8, p < 10-4), and an extended time since immunization (≥75 days; OR = 4.3, p = 0.002). Double defective cellular/humoral responses (6.9%) were typically encountered in glucocorticoids and/or anti-CD20 mAb treated ISD with a serum albumin level ≤40 g/L (OR = 17.5; p = 0.002). Glucocorticoid usage, B cell depleting therapies, and a low serum albumin level were the main factors associated with a non-response to COVID-19 immunization in ISD patients. These results need further confirmation in larger studies.

Humoral and Cellular Responses to a Delayed Fourth SARS-CoV-2 mRNA-Based Vaccine in Weak Responders to 3 Doses Kidney Transplant Recipients.

While kidney transplant recipients (KTRs) represent a high-risk population for severe SARS-CoV-2 infection, almost half of them do not develop adequate levels of antibodies conferring clinical protection despite 3 doses of the mRNA vaccine. In the present study we retrospectively analyzed the humoral and cellular responses resulting from a fourth dose of vaccine administered to KTRs having an anti-SARS-CoV-2 antibody titer below 142 binding antibody unit (BAU)/mL at 3 months post-third-dose. We observed a significant increase in anti-SARS-CoV-2 antibody concentration from 6.1 (Q1 4.3; Q3 12.7) BAU/mL on the day of the fourth dose to 1054.0 (Q1 739.6; Q3 1649.0) BAU/mL one month later (p = 0.0007), as well as neutralizing antibody titers (from 0.0 (Q1 0.0; Q3 2.0) to 8 (4; 16) IU/mL, p = 0.01) and CD3+ T cell response (from 37.5 (Q1 12.5; Q3 147.5) to 170.0 (Q1 57.5; Q3 510.0) SFUs per 106 PBMCs, p = 0.001). Hence, delaying the fourth dose seems to improve vaccine immunogenicity in KTRs, compared with previously reported data obtained in respect of a fourth dose one month after the third dose. Nevertheless, antibody concentrations seem to remain insufficient to confer clinical protection, especially for Omicron, for which breakthrough infections occur even at very high concentrations.

Predictive Factors for Humoral Response After 2-dose SARS-CoV-2 Vaccine in Solid Organ Transplant Patients.

BACKGROUND: A weak immunogenicity has been reported in solid organ transplant (SOT) recipients after 2 doses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. The aim of this retrospective study was to identify the predictive factors for humoral response in SOT patients. METHODS: Three hundred and ninety-three SOT patients from our center with at least 4 wk of follow-up after 2 doses of mRNA-based vaccine were included in this study. Anti-SARS-Cov-2 spike protein antibodies were assessed before and after vaccination. RESULTS: Anti-SARS-CoV-2 antibodies were detected in 34% of the patients: 33.7% of kidney transplant patients, 47.7% of liver transplant patients, and 14.3% of thoracic transplant patients (P = 0.005). Independent predictive factors for humoral response after vaccination were male gender, a longer period between transplantation and vaccination, liver transplant recipients, a higher lymphocyte count at baseline, a higher estimated glomerular filtration rate and receiving the tacrolimus + everolimus ± steroids combination. Conversely, the nondevelopment of anti-SARS-CoV-2 antibodies after vaccination was associated with younger patients, thoracic organ recipients, induction therapy recipients, and tacrolimus + mycophenolic acid ± steroids recipients. CONCLUSIONS: The immunosuppressive regimen is a modifiable predictive factor for humoral response to SARS-CoV-2 vaccine.

Novel T cell interferon gamma release assay (IGRA) using spike recombinant protein for COVID19 vaccine response and Nucleocapsid for SARS-Cov2 response.

We explored the performance of a whole blood interferon gamma release assay (IGRA) based on the stimulation of SARS-Cov2-specific T cells by purified recombinant proteins. Twenty volunteers vaccinated with BNT162b2 were selected first for T cell response evaluation using an in-house IGRA, a commercial IGRA, and ELISpot showing a S2 > S1 poly-epitopic response. Next, 64 vaccinated and 103 non-vaccinated individuals were tested for humoral and T cell response (IGRA-Spike/-nucleocapsid recombinant proteins). Following the second vaccine injection, humoral (100%) and IGRA-Spike T cell (95.3%) responses took place irrespective of sex, age, and vaccine type. The humoral response declined first, followed by IGRA-Spike T cell response after the second vaccine injection. Altogether, this study confirms the utility of the IGRA-Spike/-nucleocapsid assay to complement serology in COVID19 vaccinated individuals and those who have recovered from SARS-Cov2.

Humoral and Cellular Immune Responses of Solid Organ Transplant Patients on Belatacept to Three Doses of mRNA-Based Anti-SARS-CoV-2 Vaccine.

BACKGROUND: Two doses of anti-SARS-CoV-2 mRNA-based vaccines are poorly immunogenic in solid organ transplant recipients (SOT). METHODS: In total, 68 belatacept-treated SOT recipients followed at the Toulouse University Hospital were investigated. They were given three injections of the BNT162b2 mRNA COVID-19 vaccine. Their humoral response was assessed by determining anti-spike antibodies and neutralizing antibodies. The T-cell responses were assessed using an enzyme-linked immunospot assay that measured the interferon-γ produced by specific SARS-CoV-2 T-cells in a subgroup of 17 patients. RESULTS: Only 23.5% of these patients developed a detectable anti-spike response. Moreover, the cellular and the humoral responses were well correlated. Patients with no humoral response were also without a detectable cellular response. Those belatacept-treated patients who developed an Anti-SARS-CoV-2 humoral response were younger, had been transplanted for longer, and had a higher lymphocyte count and a better glomerular filtration rate than those with no response. Finally, patients on tacrolimus plus belatacept produced a lower immune response. CONCLUSIONS: Belatacept-treated SOT recipients have a reduced immune response to anti-SARS-CoV-2 mRNA vaccination. The vaccine should be given quite separately from the belatacept infusion to improve immunogenicity. Studies to assess whether switching to another immunosuppressive regimen can improve the post-vaccination immune response would be useful.

Influence of the Delta Variant and Vaccination on the SARS-CoV-2 Viral Load.

Studies comparing SARS-CoV-2 nasopharyngeal (NP) viral load (VL) according to virus variant and host vaccination status have yielded inconsistent results. We conducted a single center prospective study between July and September 2021 at the drive-through testing center of the Toulouse University Hospital. We compared the NP VL of 3775 patients infected by the Delta (n = 3637) and Alpha (n = 138) variants, respectively. Patient's symptoms and vaccination status (2619 unvaccinated, 636 one dose and 520 two doses) were recorded. SARS-CoV-2 RNA testing and variant screening were assessed by using Thermo Fisher® TaqPath™ COVID-19 and ID solutions® ID™ SARS-CoV-2/VOC evolution Pentaplex assays. Delta SARS-CoV-2 infections were associated with higher VL than Alpha (coef = 0.68; p ≤ 0.01) independently of patient's vaccination status, symptoms, age and sex. This difference was higher for patients diagnosed late after symptom onset (coef = 0.88; p = 0.01) than for those diagnosed early (coef = 0.43; p = 0.03). Infections in vaccinated patients were associated with lower VL (coef = -0.18; p ≤ 0.01) independently of virus variant, symptom, age and sex. Our results suggest that Delta infections could lead to higher VL and for a longer period compared to Alpha infections. By effectively reducing the NP VL, vaccination could allow for limiting viral spread, even with the Delta variant.

Anti-SARS-CoV-2 spike protein and neutralizing antibodies at 1 and 3 months after three doses of SARS-CoV-2 vaccine in a large cohort of solid organ transplant patients.

The immunogenicity of the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) vaccine was improved by the administration of a third dose. The aim of our retrospective study was to assess the evolution of binding and neutralizing antibody concentration until 3 months after the third dose in a large cohort of solid organ transplant (SOT) patients (n = 872). At 1 month after the third dose, anti-SARS-CoV-2 antibodies were detected by means of enzyme-linked immunosorbent assay tests in 578 patients (66.3%). In a subgroup of patients, 70% (180 out of 257) had anti-SARS-CoV-2 antibody concentrations ranging from 1.2 to 18 411 binding antibody units (BAU)/ml and 48.5% (115 out of 239) had a neutralizing antibodies titer that can confer clinical protection against SARS-CoV-2. Three-hundred ninety-three patients out of the 416 (94.5%) who were seropositive at month 1 and were tested at 3 months after vaccination remained seropositive. Between months 1 and 3 after vaccination, binding and neutralizing antibodies concentrations decreased significantly. The proportion of protected patients against the SARS-CoV-2 also slightly decreased. In conclusion, this study shows that although two-third of SOT develop anti-SARS-CoV-2 antibodies after three doses, one-third of them remain weak or non-protected. It is important to measure anti-SARS-CoV-2 antibodies to define the strategy that can optimize SOT protection against SARS-CoV-2.

Evaluation of Three Quantitative Anti-SARS-CoV-2 Antibody Immunoassays.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in December 2019 and caused a dramatic pandemic. Serological assays are used to check for immunization and assess herd immunity. We evaluated commercially available assays designed to quantify antibodies directed to the SARS-CoV-2 Spike (S) antigen, either total (Wantaï SARS-CoV-2 Ab ELISA) or IgG (SARS-CoV-2 IgG II Quant on Alinity, Abbott, and Liaison SARS-CoV-2 TrimericS IgG, Diasorin). The specificities of the Wantaï, Alinity, and Liaison assays were evaluated using 100 prepandemic sera and were 98, 99, and 97%, respectively. The sensitivities of all three were around 100% when tested on 35 samples taken 15 to 35 days postinfection. They were less sensitive for 150 sera from late infections (>180 days). Using the first WHO international standard (NIBSC), we showed that the Wantai results were concordant with the NIBSC values, while Liaison and Alinity showed a proportional bias of 1.3 and 7, respectively. The results of the 3 immunoassays were significantly globally pairwise correlated and for late infection sera (P < 0.001). They were correlated for recent infection sera measured with Alinity and Liaison (P < 0.001). However, the Wantai results of recent infections were not correlated with those from Alinity or Liaison. All the immunoassay results were significantly correlated with the neutralizing antibody titers obtained using a live virus neutralization assay with the B1.160 SARS-CoV-2 strain. These assays will be useful once the protective anti-SARS-CoV-2 antibody titer has been determined. IMPORTANCE Standardization and correlation with virus neutralization assays are critical points to compare the performance of serological assays designed to quantify anti-SARS-CoV-2 antibodies in order to identify their optimal use. We have evaluated three serological immunoassays based on the virus spike antigen that detect anti-SARS-CoV-2 antibodies: a microplate assay and two chemiluminescent assays performed with Alinity (Abbott) and Liaison (Diasorin) analysers. We used an in-house live virus neutralization assay and the first WHO international standard to assess the comparison. This study could be useful to determine guidelines on the use of serological results to manage vaccination and treatment with convalescent plasma or monoclonal antibodies.

Testing individual and pooled saliva samples for sars-cov-2 nucleic acid: a prospective study.

Control of the rapid spread of the SARS-CoV-2 virus requires efficient testing. We collected paired nasopharyngeal swab (NPs) and saliva samples from 303 subjects (52.8% symptomatic) at a drive-through testing center; 18% of whom tested positive. The NPs, salivas and five saliva pools were tested for SARS-CoV-2 RNA using the Aptima™ assay and a laboratory-developed test (LDT) on the Panther-Fusion™ Hologic® platform. The saliva sensitivity was 80% (LDT) and 87.5% (Aptima™) whereas that of NPs was 96.4% in both assays. The pooled saliva sensitivity of 72.7% (LDT) and 75% (Aptima™) was not significantly different of that of individual saliva testing. Saliva specimens appear to be suitable for sensitive non-invasive assays to detect SARS-CoV-2 nucleic acid; pooling them for a single test will improve laboratory throughput.

Adaptive lymphocyte profile analysis discriminates mild and severe forms of COVID-19 after solid organ transplantation.

Solid organ transplant recipients are at high risk for the development of severe forms of COVID-19. However, the role of immunosuppression in the morbidity and mortality of the immune phenotype during COVID-19 in transplant recipients remains unknown. In this retrospective study, we compared peripheral blood T and B cell functional and surface markers, as well as serum antibody development during 29 cases of mild (World Health Organization 9-point Ordinal Scale (WOS) of 3-4) and 22 cases of severe COVID-19 (WOS 5-8) in solid organ transplant (72% kidney transplant) recipients hospitalized in our center. Patients who developed severe forms of COVID-19 presented significantly lower CD3+ (median 344/mm3 (inter quartile range 197; 564) vs. 643/mm3 (397; 1251)) and CD8+ T cell counts (124/mm3 (76; 229) vs. 240/mm3 (119; 435)). However, activated CD4+ T cells were significantly more frequent in severe forms (2.9% (1.37; 5.72) vs. 1.4% (0.68; 2.35)), counterbalanced by a significantly higher proportion of Tregs (3.9% (2.35; 5.87) vs. 2.7% (1.9; 3.45)). A marked decrease in the proportion of NK cells was noted only in severe forms. In the B cell compartment, transitional B cells were significantly lower in severe forms (1.2% (0.7; 4.2) vs. 3.6% (2.1; 6.2)). Nonetheless, a majority of transplant recipients developed antibodies against SARS-CoV-2 (77% and 83% in mild and severe forms, respectively). Thus, our data revealed immunological differences between mild and severe forms of COVID-19 in solid organ transplant recipients, similar to previous reports in the immunocompetent population.