Androgen receptor polyQ alleles and COVID-19 severity in men: a replication study (preprint)

Ample evidence indicates a sex-related difference in severity of COVID-19, with less favorable outcomes observed in men. Genetic factors have been proposed as candidates to explain this difference. The polyQ polymorphism in the androgen receptor gene has been recently described as a genetic biomarker of COVID-19 severity. In this study, we analyzed this association in a large cohort of 1136 men classified into three groups according to their degree of COVID-19 severity, finding a similar distribution of polyQ alleles among severity groups. Therefore, our results do not support the role of this polymorphism as a biomarker of COVID-19 severity.

DECREASED BREADTH OF THE ANTIBODY RESPONSE TO THE SPIKE PROTEIN OF SARS-CoV-2 AFTER REPEATED VACCINATION (preprint)

ABSTRACT The rapid development of vaccines to prevent infection by SARS-CoV-2 virus causing COVID-19 makes necessary to compare the capacity of the different vaccines in terms of development of a protective humoral response. Here, we have used a highly sensitive and reliable flow cytometry method to measure the titers of antibodies of the IgG1 isotype in blood of healthy volunteers after receiving one or two doses of the vaccines being administered in Spain. We took advantage of the multiplexed capacity of the method to measure simultaneously the reactivity of antibodies with the S protein of the original strain Wuhan and the variants B.1.1.7 (Alpha), B.1.617.2 (Delta) and B.1.617.1 (Kappa). We found significant differences in the titer of anti-S antibodies produced after a first dose of the vaccines ChAdOx1 nCov-19/AstraZeneca, mRNA-1273/Moderna, BNT162b2/Pfizer-BioNTech and Ad26.COV.S/Janssen. Most important, we found a relative reduction in the reactivity of the sera with the Alpha, Delta and Kappa variants, versus the Wuhan one, after the second boosting immunization. These data allow to make a comparison of different vaccines in terms of anti-S antibody generation and cast doubts about the convenience of repeatedly immunizing with the same S protein sequence.

Differential Effects of the Second SARS-CoV-2 mRNA Vaccine Dose on T Cell Immunity in Naïve and COVID-19 Recovered Individuals (preprint)

The rapid development and deployment of mRNA-based vaccines against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) led to the design of accelerated vaccination schedules that have been extremely effective in naïve individuals. While a two-dose immunization regimen with the BNT162b2 vaccine has been demonstrated to provide a 95% efficacy in naïve individuals, the effects of the second vaccine dose in individuals who have previously recovered from natural SARS-CoV-2 infection has not been investigated in detail. Here we characterized, SARS-CoV-2 spike-specific humoral and cellular immunity in naïve and previously infected individuals during and after two-doses of BNT162b2 vaccination. Our results demonstrate that, while the second dose increases both the humoral and cellular immunity in naïve individuals, COVID-19 recovered individuals reach their peak of immunity after the first dose. These results suggests that a second dose, according to the current standard regimen of vaccination, may be not necessary in individuals previously infected with SARS-CoV-2.Funding: Research reported in this publication was supported in part by National Cancer Institute of the NIH (5R01HD102614-02; R01CA249204 and R01CA248984) and ISMMS seed fund to EG. The authors gratefully acknowledge use of the services and facilities of the Tisch Cancer Institute supported by the NCI Cancer Center Support Grant (P30 CA196521). MS was supported by a NCI training grant (T32CA078207). This work was supported by ISMMS seed fund to JO; Instituto de Salud Carlos III, COV20-00668 to RCR; Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation (COVID-19 Research Call COV20/00181) co-financed by European Development Regional Fund “A way to achieve Europe” to EP; Instituto de Salud Carlos III, Spain (COV20/00170); Government of Cantabria, Spain (2020UIC22-PUB 0019) to MLH; Instituto de Salud Carlos III (PI16CIII/00012) to PP; Fondo Social Europeo e Iniciativa de Empleo Juvenil YEI (Grant PEJ2018-004557-A) to MPE; REDInREN 016/009/009 ISCIII; This project has received funding from the European Union’s Horizon 2020 research and innovation programme VACCELERATE under grant agreement No [101037867] to JO.Conflict of Interest: AB declares the filling of a patent application relating to the use of peptide pools in whole blood for detection of SARS-CoV-2 T cells (pending). The other authors declare no competing interests.Ethical Approval: The study protocols for the collection of clinical specimens from individuals with and without SARS-CoV-2 infection were reviewed and approved by Hospital La Paz, Hospital 12 de Octubre, Hospital Gregorio Marañón, IIS-Fundación Jimenez Díaz, Hospital Universitario Marqués de Valdecilla-IDIVAL and Hospital Puerta de Hierro Clinical Research Ethics Committee (CEIm), and Mount Sinai Hospital Institutional Review Board (IRB).

Differential effects of the second SARS-CoV-2 mRNA vaccine dose on T cell immunity in naive and COVID-19 recovered individuals (preprint)

The rapid development and deployment of mRNA-based vaccines against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) led to the design of accelerated vaccination schedules that have been extremely effective in naive individuals. While a two-dose immunization regimen with the BNT162b2 vaccine has been demonstrated to provide a 95% efficacy in naive individuals, the effects of the second vaccine dose in individuals who have previously recovered from natural SARS-CoV-2 infection has been questioned. Here we characterized SARS-CoV-2 spike-specific humoral and cellular immunity in naive and previously infected individuals during full BNT162b2 vaccination. Our results demonstrate that the second dose increases both the humoral and cellular immunity in naive individuals. On the contrary, the second BNT162b2 vaccine dose results in a reduction of cellular immunity in COVID-19 recovered individuals, which suggests that a second dose, according to the current standard regimen of vaccination, may be not necessary in individuals previously infected with SARS-CoV-2.

Combination therapy with tocilizumab and corticosteroids for aged patients with severe COVID-19 pneumonia: a single-center retrospective study. (preprint)

Background: The role of combination immunomodulatory therapy with systemic corticosteroids and tocilizumab (TCZ) for aged patients with COVID19 associated cytokine release syndrome remains unclear. Methods: We conducted a retrospective single center study including consecutive patients older than 65 years that developed severe COVID19 between March 3 and May 1, 2020 and were treated with corticosteroids at various doses (methylprednisolone [0.5 mg/Kg/12 hours to 250 mg/24 hours]), either alone (CS group) or associated to intravenous tocilizumab (400 to 600 mg, one to three doses) (CS/TCZ group). Primary outcome was all cause mortality by day +14, whereas secondary outcomes included mortality by day +28 and clinical improvement (discharge and/or a 2 point decrease on a six point ordinal scale) by day +14. Propensity score (PS)based adjustment and inverse probability of treatment weights (IPTW) were applied. Results: Overall, 181 and 80 patients were included in the CS and CS TCZ groups. All cause 14 day mortality was lower in the CS/TCZ group, both in the PS adjusted (hazard ratio [HR]: 0.34; 95% confidence interval [CI]: 0.17 to 0.68; P value = 0.002) and IPTW weighted models (odds ratio [OR]: 0.38; 95% CI: 0.21 to 0.68; P value = 0.001). This protective effect was also observed for 28 day mortality (PS adjusted HR: 0.38; 95% CI: 0.21 to 0.72; P value = 0.003). Clinical improvement by day +14 was higher in the CS/TCZ group in the IPTW analysis only (OR: 2.26; 95% CI: 1.49 to 3.41; P value <0.001). The occurrence of secondary infection was similar between both groups. Conclusions: The combination of corticosteroids and TCZ was associated with better outcomes among patients older than 65 years with severe COVID-19.

Magnitude and Dynamics of the T-Cell Response to SARS-CoV-2 Infection at Both Individual and Population Levels (preprint)

T cells are involved in the early identification and clearance of viral infections and also support the development of antibodies by B cells. This central role for T cells makes them a desirable target for assessing the immune response to SARS-CoV-2 infection. Here, we combined two high-throughput immune profiling methods to create a quantitative picture of the T-cell response to SARS-CoV-2. First, at the individual level, we deeply characterized 3 acutely infected and 58 recovered COVID-19 subjects by experimentally mapping their CD8 T-cell response through antigen stimulation to 545 Human Leukocyte Antigen (HLA) class I presented viral peptides (class II data in a forthcoming study). Then, at the population level, we performed T-cell repertoire sequencing on 1,015 samples (from 827 COVID-19 subjects) as well as 3,500 controls to identify shared "public" T-cell receptors (TCRs) associated with SARS-CoV-2 infection from both CD8 and CD4 T cells. Collectively, our data reveal that CD8 T-cell responses are often driven by a few immunodominant, HLA-restricted epitopes. As expected, the T-cell response to SARS-CoV-2 peaks about one to two weeks after infection and is detectable for several months after recovery. As an application of these data, we trained a classifier to diagnose SARS-CoV-2 infection based solely on TCR sequencing from blood samples, and observed, at 99.8% specificity, high early sensitivity soon after diagnosis (Day 3-7 = 83.8% [95% CI = 77.6-89.4]; Day 8-14 = 92.4% [87.6-96.6]) as well as lasting sensitivity after recovery (Day 29+/convalescent = 96.7% [93.0-99.2]). These results demonstrate an approach to reliably assess the adaptive immune response both soon after viral antigenic exposure (before antibodies are typically detectable) as well as at later time points. This blood-based molecular approach to characterizing the cellular immune response has applications in vaccine development as well as clinical diagnostics and monitoring.