Impact of COVID-19 on the liver and on the care of patients with chronic liver disease, hepatobiliary cancer, and liver transplantation: An updated EASL position paper

Journal of Hepatology, Journal Year: 2022, Volume and Issue: 77(4), P. 1161 - 1197

Published: July 20, 2022

Language: Английский

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Older Adults Mount Less Durable Humoral Responses to Two Doses of COVID-19 mRNA Vaccine but Strong Initial Responses to a Third Dose

The Journal of Infectious Diseases, Journal Year: 2022, Volume and Issue: 226(6), P. 983 - 994

Published: May 10, 2022

Third coronavirus disease 2019 (COVID-19) vaccine doses are broadly recommended, but immunogenicity data remain limited, particularly in older adults.We measured circulating antibodies against the severe acute respiratory syndrome 2 (SARS-CoV-2) spike protein receptor-binding domain, ACE2 displacement, and virus neutralization ancestral omicron (BA.1) strains from prevaccine up to 1 month following third dose, 151 adults aged 24-98 years who received COVID-19 mRNA vaccines.Following doses, humoral immunity was weaker, less functional, durable adults, where a higher number of chronic health conditions key correlate weaker responses poorer durability. One after antibody concentrations function exceeded post-second-dose levels, were comparable magnitude those younger at this time. Humoral universally than strain both second doses. Nevertheless, 3 anti-omicron reached equivalence adults. conditions, not age, strongest consistent responses.Results underscore immune benefits

Language: Английский

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Potential immune evasion of the severe acute respiratory syndrome coronavirus 2 Omicron variants

Frontiers in Immunology, Journal Year: 2024, Volume and Issue: 15

Published: Feb. 23, 2024

Coronavirus disease 2019 (COVID-19), which is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has a global pandemic. The Omicron variant (B.1.1.529) was first discovered in November 2021 specimens collected from Botswana, South Africa. become dominant worldwide, and several sublineages or subvariants have been identified recently. Compared to those of other mutants, most highly expressed amino acid mutations, with almost 60 mutations throughout genome, are spike (S) protein, especially receptor-binding domain (RBD). These increase binding affinity variants for ACE2 receptor, may also lead immune escape. Despite causing milder symptoms, epidemiological evidence suggests that exceptionally higher transmissibility, rates reinfection greater spread than prototype strain as well preceding variants. Additionally, overwhelming amounts data suggest levels specific neutralization antibodies against decrease vaccinated populations, although CD4 + CD8 T-cell responses maintained. Therefore, mechanisms underlying evasion still unclear. In this review, we surveyed current epidemic status potential escape Especially, focused on roles viral epitope antigenic drift, hybrid immunity, “original sin” mediating evasion. insights might supply more valuable concise information us understand spreading

Language: Английский

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Booster COVID-19 vaccination against the SARS-CoV-2 Omicron variant: A systematic review

Human Vaccines & Immunotherapeutics, Journal Year: 2022, Volume and Issue: 18(5)

Published: May 2, 2022

There is a wealth of data suggesting that the effectiveness existing vaccines against Omicron variant, most mutated SARS-CoV-2 variant to date, has been substantially reduced if only primary vaccination administered. Therefore, booster become topic current interest. We conducted comprehensive search in PubMed, Embase, and Cochrane Library collect various pseudovirus neutralization tests or live virus for with serum specimens from vaccinees. extracted titers original strain, other variants before after vaccination, then manually calculated fold increase decrease relative variants, compared vaccination. In two-dose regimen, decreased strain variants. However, both homologous heterologous antibodies was significantly improved, although still lower than The program based on can produce broad but incomplete immunity variant.

Language: Английский

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Sub‐lineages of the SARS‐CoV‐2 Omicron variants: Characteristics and prevention

MedComm, Journal Year: 2022, Volume and Issue: 3(3)

Published: Aug. 16, 2022

Abstract Since the start of coronavirus disease 2019 (COVID‐19) pandemic, new variants severe acute respiratory syndrome 2 (SARS‑CoV‑2) have emerged, accelerating spread virus. Omicron was defined by World Health Organization in November 2021 as fifth “variant concern” after Alpha, Beta, Gamma, and Delta. In recent months, has become main epidemic strain. Studies shown that carries more mutations than Delta, wild‐type, facilitating immune escape its transmission. This review focuses on variant's origin, transmission, biological features, subvariants, mutations, escape, vaccination, detection methods. We also discuss appropriate preventive therapeutic measures should be taken to address challenges posed variant. is valuable guide surveillance, prevention, development vaccines other therapies for variants. It desirable develop a efficient vaccine against variant take effective constrain promote public health.

Language: Английский

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Methodological approaches to optimize multiplex oral fluid SARS-CoV-2 IgG assay performance and correlation with serologic and neutralizing antibody responses

Journal of Immunological Methods, Journal Year: 2023, Volume and Issue: 514, P. 113440 - 113440

Published: Feb. 9, 2023

Language: Английский

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A SARS-CoV-2 RBD vaccine fused to the chemokine MIP-3α elicits sustained murine antibody responses over 12 months and enhanced lung T-cell responses

Frontiers in Immunology, Journal Year: 2024, Volume and Issue: 15

Published: Feb. 2, 2024

Background Previous studies have demonstrated enhanced efficacy of vaccine formulations that incorporate the chemokine macrophage inflammatory protein 3α (MIP-3α) to direct antigens immature dendritic cells. To address reduction in associated with a mutation severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mutants, we examined ability receptor-binding domain vaccines incorporating MIP-3α sustain higher concentrations antibody when administered intramuscularly (IM) and more effectively elicit lung T-cell responses intranasally (IN). Methods BALB/c mice aged 6–8 weeks were immunized or DNA constructs consisting SARS-CoV-2 alone fused MIP-3α. In small-scale ( n = 3/group) experiment, IM electroporation followed up for serum over period 1 year bronchoalveolar levels at termination study. Following IN immunization unencapsulated plasmid 6/group), evaluated 11 concentrations, quantities T cells lungs, IFN-γ- TNF-α-expressing antigen-specific lungs spleen. Results At 12 months postprimary vaccination, recipients had significantly, approximately threefold, than not The area-under-the-curve analyses 12-month observation interval significantly greater time formulation. immunization, only fusion serum-neutralizing activity deemed be effective. After intranasal developed above those PBS controls. Low obtained following immunization. Conclusion Although requiring separate immunizations optimal construct potential stable easily produced formulation provide extended may required protection setting emerging variants. Without electroporation, simple, uncoated elicited responses.

Language: Английский

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Immunogenicity evaluation after BNT162b2 booster vaccination in healthcare workers

Scientific Reports, Journal Year: 2022, Volume and Issue: 12(1)

Published: July 26, 2022

Waning of the immune response upon vaccination in SARS-CoV-2 infection is an important subject evaluation this pandemic, mostly healthcare workers (HCW) that are constantly contact with infected samples and patients. Therefore, our study aimed to establish specific humoral IgG IgA antibodies vaccination, during second year pandemic evaluating booster shot same vaccine type. A group 103 HCW documented exposure virus were monitored for levels prior after first round, following 8 months After post-vaccination both decreased, 2.4 times IgG, 2.7 IgA. Although significantly no was registered group. shot, entire group, displayed increased levels, immediately followed by increase post-second round statistically higher compared while restored at levels. Within or routine a multiple waves' generating new variants, populational immunity remains issue future implementation prevention/control measures.

Language: Английский

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Higher correlation between neutralizing antibodies and surrogate neutralizing or binding antibodies in COVID-19 patients than vaccine recipients

PLoS ONE, Journal Year: 2024, Volume and Issue: 19(4), P. e0298033 - e0298033

Published: April 16, 2024

This study determined the seropositive rates and levels of antibodies to severe acute respiratory syndrome coronavirus-2 in 50 patients 108 vaccinees using microneutralization test (MNT), surrogate virus neutralization (sVNT), chemiluminescent microparticle immunoassay (CMIA), electrochemiluminescence (ECLIA). MNT, as reference method, employed living clade S Delta viruses measure neutralizing (NT) antibodies, while sVNT wild type strain receptor-binding domains (RBD) antigens antibodies. CMIA ECLIA only one version RBD binding Our performed gene sequencing exclude undesired mutants that might lead changes antibody MNT assay. We showed spike protein amino acid sequences our contained 13 changes, with 3 related reduced neutralization. The assay a significant reduction patients’ sera when variant replaced virus. In contrast, by were non-significantly different, suggesting could not identify difference between antigenicity RBD. Furthermore, correlation NT was moderate but modest post-vaccination sera. patients, or ECLIA, different from S, Delta, all analyses, correlations measured other assays moderate, r -values 0.3500–0.7882.

Language: Английский

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Immune response kinetics to SARS-CoV-2 infection and COVID-19 vaccination among nursing home residents—Georgia, October 2020–July 2022

PLoS ONE, Journal Year: 2024, Volume and Issue: 19(4), P. e0301367 - e0301367

Published: April 16, 2024

Background Understanding the immune response kinetics to SARS-CoV-2 infection and COVID-19 vaccination is important in nursing home (NH) residents, a high-risk population. Methods An observational longitudinal evaluation of 37 consenting vaccinated NH residents with/without from October 2020 July 2022 was conducted characterize spike protein due and/or mRNA vaccine. Antibodies (IgG) full-length spike, nucleocapsid, receptor binding domain antigens were measured, surrogate virus neutralization capacity assessed using Meso Scale Discovery immunoassays. The participant’s exposure status varied depending on acquisition or receipt vaccine dose. Longitudinal linear mixed effects modeling used describe trajectories based last vaccination; primary series considered two exposures. Mean antibody titer values participants who developed an post compared with those did not. In subset (n = 15), memory B cell (MBC) S-specific IgG (%S IgG) responses ELISPOT assay. Results median age at enrollment 70.5 years; 30 (81%) had prior infection, 76% received Pfizer-BioNTech 24% Moderna homologous vaccines. After observed augmented effect each exposure, decline response, including %S MBCs, over time; percent decreased increasing Participants least weeks post-receipt have lower humoral levels than not develop post-receipt. Conclusions These findings suggest that understanding durability this vulnerable population can help inform public health policy regarding timing booster vaccinations as new variants display escape.

Language: Английский

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