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1.
American Journal of Transplantation ; 22(Supplement 3):1058-1059, 2022.
Article in English | EMBASE | ID: covidwho-2063534

ABSTRACT

Purpose: To evaluate the safety and generation rate of Ab anti spike rate in SOT patients at 28 and 90 days after completing the Covid 19 vaccination scheme. Method(s): Multicenter prospective study in SOT with a complete vaccination scheme who agreed to participate in the study . Demographic , vaccination: schedule;time;adverse effects and transplant variables were collected. The generation rate of antispike antibodies was evaluated by the COVIDAR-IgG method at the Universidad de Buenos Aires School of Medicine. Result(s): 113 SOT patients were included (September 6th to October 4th). Median age was 53 (IQR 42.5-63, women 36.8%). Transplant type: 72.8% renal , 13.1% cardiac, 12.3% liver, 0.9% pancreas and 0.9% lung. Deceased donors 71.1%. The median time after transplantation to vaccination was 65 months (IQR 30 120 R 2-429). Only 7% of patients developed rejection within the year prior to vaccination and no patient rejected post vaccination. 74.3% (n 84) had triple immunosuppressive maintenance regimen (steroids + calcineurin inhibitors (ICN) + antiproliferative), 24 pts (21.1%) double regimen WITHOUT steroids and 5 (4.3%) monotherapy with IC. Vaccination schedule: Sputnik 14.5%, Sputnik-Astrazeneca 4.4%, Sputnik-Moderna 28.9%, Sinopharm 3.5%, Astrazeneca 34.2%. Vaccine-related adverse events were observed in 18.4% of patients, 82% were mild. 40% of SOT responded with Antispike Ab , with a lower response rate in kidney transplantation p <0.0007 RR 0.48 (0.32-0.71) and use of triple immunosuppressive maintenance regimen p <0.00009 RR 0.419 (0.26 -0.66). Patients previously infected with Covid-19 prior to vaccine (11.45% pts), had a higher response rate p <0.0001 RR 2.58 (1.90-3.51).No patients developed COVID-19 after vaccination. Conclusion(s): In our SOT population, a lower generation rate of anti-spike Ab was observed, compared to the reported in the general population. Renal Tx and the triple IS regimen were associated with a lower response rate. Covid-19 prior to vaccination was associated with a higher antibody response to the vaccine.

2.
Public Health Pract (Oxf) ; 4: 100313, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2008062

ABSTRACT

Objectives: In a context of COVID-19 vaccine shortages, this study sought to evaluate the safety and efficacy of receiving one dose of Gam-COVID-Vac rAd26 followed by a second COVID-19 vaccine dose of either Gam-COVID-Vac rAd5, ChAdOx1 nCoV-19 or BBIBP-CorV in a cohort of older adults. Study design: Single-centre, randomised, open label, non-inferiority trial. Methods: Adults aged ≥65 years who had received one dose of Gam-COVID-Vac rAd26 were randomised in a 1:1:1 ratio to receive a second-dose COVID-19 vaccination of either Gam-COVID-Vac rAd5, ChAdOx1 nCoV-19 or BBIBP-CorV. The primary outcome was the assessment of the humoral immune response to vaccination (i.e. antibody titres of SARS-CoV-2 spike protein at 28 days after second-dose vaccination). In addition, neutralising antibody titres at day 28 for the three schedules were measured. Results: Of 85 participants who were enrolled in the study between 26 and July 30, 2021, 31 individuals were randomised to receive Gam-COVID-Vac rAd5, 27 to ChAdOx1 nCoV-19 and 27 to BBIBP-CorV. The mean age of participants was 68.2 years (SD 2.9) and 49 (57.6%) were female. Participants who received Gam-COVID-Vac rAd5 and ChAdOx1 nCoV1-19 showed significantly increased anti-S titres at 28 days after second-dose vaccination, but this magnitude of difference was not observed for those who received BBIBP-CorV. The ratio between the geometric mean at day 28 and baseline within each group was 11.8 (6.98-19.89) among patients assigned to Gam-COVID-Vac rAd26/rAd5, 4.81 (2.14-10.81) for the rAd26/ChAdOx1 nCoV-19 group and 1.53 (0.74-3.20) for the rAd26/BBIBP-CorV group. All of the schedules were shown to be safe. Conclusions: The findings in this study contribute to the scarce information published on the safety and immunogenicity of Gam-COVID-Vac heterologous regimens and will help the development of guidelines and vaccine programme management.

3.
Mbio ; 13(1):9, 2022.
Article in English | Web of Science | ID: covidwho-1766682

ABSTRACT

Recent studies have shown a temporal increase in the neutralizing antibody potency and breadth to SARS-CoV-2 variants in coronavirus disease 2019 (COVID-19) convalescent individuals. Here, we examined longitudinal antibody responses and viral neutralizing capacity to the B.1 lineage virus (Wuhan related), to variants of concern (VOC;Alpha, Beta, Gamma, and Delta), and to a local variant of interest (VOI;Lambda) in volunteers receiving the Sputnik V vaccine in Argentina. Longitudinal serum samples (N = 536) collected from 118 volunteers obtained between January and October 2021 were used. The analysis indicates that while anti-spike IgG levels significantly wane over time, the neutralizing capacity for the Wuhan-related lineages of SARS-CoV-2 and VOC is maintained within 6 months of vaccination. In addition, an improved antibody cross-neutralizing ability for circulating variants of concern (Beta and Gamma) was observed over time postvaccination. The viral variants that displayed higher escape to neutralizing antibodies with respect to the original virus (Beta and Gamma variants) were the ones showing the largest increase in susceptibility to neutralization over time after vaccination. Our observations indicate that serum neutralizing antibodies are maintained for at least 6 months and show a reduction of VOC escape to neutralizing antibodies over time after vaccination. IMPORTANCE Vaccines have been produced in record time for SARS-CoV-2, offering the possibility of halting the global pandemic However, inequalities in vaccine accessibility in different regions of the world create a need to increase international cooperation. Sputnik V is a recombinant adenovirus-based vaccine that has been widely used in Argentina and other developing countries, but limited information is available about its elicited immune responses. Here, we examined longitudinal antibody levels and viral neutralizing capacity elicited by Sputnik V vaccination. Using a cohort of 118 volunteers, we found that while anti-spike antibodies wane over time, the neutralizing capacity to viral variants of concern and local variants of interest is maintained within 4 months of vaccination. In addition, we observed an increased cross-neutralization activity over time for the Beta and Gamma variants. This study provides valuable information about the immune response generated by a vaccine platform used in many parts of the world.

4.
Embase;
Preprint in English | EMBASE | ID: ppcovidwho-326896

ABSTRACT

Numerous safe and effective COVID-19 vaccines have been developed that utilize various delivery technologies and engineering strategies. The influence of the SARS-CoV2 spike (S) glycoprotein conformation on antibody responses induced by vaccination or infection in humans remains unknown. To address this question, we compared plasma antibodies elicited by six globally-distributed vaccines or infection and observed markedly higher binding titers for vaccines encoding a prefusion-stabilized S relative to other groups. Prefusion S binding titers positively correlated with plasma neutralizing activity, indicating that physical stabilization of the prefusion conformation enhances protection against SARS-CoV-2. We show that almost all plasma neutralizing activity is directed to prefusion S, in particular the S1 subunit, and that variant cross-neutralization is mediated solely by RBD-specific antibodies. Our data provide a quantitative framework for guiding future S engineering efforts to develop vaccines with higher resilience to the emergence of variants and longer durability than current technologies.

5.
Embase;
Preprint in English | EMBASE | ID: ppcovidwho-326798

ABSTRACT

The recently emerged SARS-CoV-2 Omicron variant harbors 37 amino acid substitutions in the spike (S) protein, 15 of which are in the receptor-binding domain (RBD), thereby raising concerns about the effectiveness of available vaccines and antibody therapeutics. Here, we show that the Omicron RBD binds to human ACE2 with enhanced affinity relative to the Wuhan-Hu-1 RBD and acquires binding to mouse ACE2. Severe reductions of plasma neutralizing activity were observed against Omicron compared to the ancestral pseudovirus for vaccinated and convalescent individuals. Most (26 out of 29) receptor-binding motif (RBM)-directed monoclonal antibodies (mAbs) lost in vitro neutralizing activity against Omicron, with only three mAbs, including the ACE2-mimicking S2K146 mAb1, retaining unaltered potency. Furthermore, a fraction of broadly neutralizing sarbecovirus mAbs recognizing antigenic sites outside the RBM, including sotrovimab2, S2X2593and S2H974, neutralized Omicron. The magnitude of Omicron-mediated immune evasion and the acquisition of binding to mouse ACE2 mark a major SARS-CoV-2 mutational shift. Broadly neutralizing sarbecovirus mAbs recognizing epitopes conserved among SARS-CoV-2 variants and other sarbecoviruses may prove key to controlling the ongoing pandemic and future zoonotic spillovers.

6.
Medicina (B Aires) ; 81(6):902-907, 2021.
Article in Spanish | PubMed | ID: covidwho-1553207

ABSTRACT

Controversies still exist regarding the humoral response to the virus SARS-CoV-2 in convalescent patients and seroconversion in patients with autoimmune diseases. There are few reports on the clinical and evolution of COVID-19 in the latter group. The objective was to examine the clinical and evolutionary characteristics associated with COVID-19 and the percentage of seroconversion in people with rheumatic diseases. Fifty-three patients were included, mainly with rheumatoid arthritis and lupus. The majority were female and average age 48 ± 14 years. Symptoms: fever (56%), anosmia (35.8%), dyspnea (34%), headache (30.2%) and cough (30.2%). Duration of infection 12 ± 7 days. Almost half of the patients were hospitalized (23, 43.4%), 5 in critical care units (9.4%) and 3 died (5.6%). The prevalence of steroid use was 56.6% (30), with an average dose of 8 mg/d, and 17 (32%) used immunosuppressive biopharmaceuticals. There was a correlation between age and the need for hospitalization with a risk of 9.4% per year. There were no differences with other variables. The presence in serum of IgG immunoglobulin against SARS-CoV-2 protein S was determined in 23/53 patients (43.4%), with detectable levels in 15 (62.2%), and in the 23 without autoimmune connective tissue diseases who suffered from COVID-19, 12 had detectable antibodies. Death in this group of rheumatic diseases was low, similar to the general population. More than half had specific antibodies against the virus regardless of the medication used.

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