Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 7 de 7
Filter
Add filters

Language
Document Type
Year range
2.
medrxiv; 2022.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2022.08.25.22279202

ABSTRACT

Immune responses in people with multiple sclerosis (pwMS) on disease-modifying therapies (DMTs) have been of significant interest throughout the COVID-19 pandemic. Lymphocyte-targeting immunotherapies including anti-CD20 treatments and sphingosine-1-phosphate receptor (S1PR) modulators attenuate antibody responses after vaccination. Evaluation of cellular responses after vaccination is therefore of particular importance in these populations. In this study, we analysed CD4 and CD8 T cell functional responses to SARS-CoV-2 spike peptides in healthy controls and pwMS on five different DMTs by flow cytometry. Although pwMS on anti-CD20 and S1PR therapies had low antibody responses after both 2 and 3 vaccine doses, T cell responses in pwMS on anti-CD20 therapies were preserved after third vaccination, even when additional anti-CD20 treatment was administered between vaccine doses 2 and 3. PwMS taking S1PR modulators had low detectable T cell responses in peripheral blood. CD4 and CD8 T cell responses to SARS-CoV-2 variants of concern Delta and Omicron were lower than to the ancestral Wuhan-Hu-1 variant. Our results indicate the importance of assessing both cellular and humoral responses after vaccination and suggest that even in the absence of robust antibody responses vaccination can generate immune responses in pwMS.


Subject(s)
Multiple Sclerosis , COVID-19
3.
biorxiv; 2022.
Preprint in English | bioRxiv | ID: ppzbmed-10.1101.2022.03.26.484261

ABSTRACT

Diagnostic assays currently used to monitor the efficacy of COVID-19 vaccines measure levels of antibodies to the receptor-binding domain of ancestral SARS-CoV-2 (RBDwt). However, the predictive value for protection against new variants of concern (VOCs) has not been firmly established. Here, we used bead-based arrays and flow cytometry to measure binding of antibodies to spike proteins and receptor-binding domains (RBDs) from VOCs in 12,000 sera. Effects of sera on RBD-ACE2 interactions were measured as a proxy for neutralizing antibodies. The samples were obtained from healthy individuals or patients on immunosuppressive therapy who had received two to four doses of COVID-19 vaccines and from COVID-19 convalescents. The results show that anti-RBDwt titers correlate with the levels of binding- and neutralizing antibodies against the Alpha, Beta, Gamma, Delta, Epsilon and Omicron variants. The benefit of multiplexed analysis lies in the ability to measure a wide range of anti-RBD titers using a single dilution of serum for each assay. The reactivity patterns also yield an internal reference for neutralizing activity and binding antibody units per milliliter (BAU/ml). Results obtained with sera from vaccinated healthy individuals and patients confirmed and extended results from previous studies on time-dependent waning of antibody levels and effects of immunosuppressive agents. We conclude that anti-RBDwt titers correlate with levels of neutralizing antibodies against VOCs and propose that our method may be implemented to enhance the precision and throughput of immunomonitoring.


Subject(s)
COVID-19
4.
medrxiv; 2022.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2022.01.27.22269895

ABSTRACT

Background: The Omicron variant of SARS-CoV-2 is now overtaking the Delta variant in many countries. Results showing that sera from double vaccinated individuals have minimal neutralizing activity against Omicron may indicate that the higher rate of transmission is due to evasion from vaccine-induced immunity. However, there is little information about activation of recall responses to Omicron in vaccinated individuals. Methods: We measured inflammatory mediators, antibodies to the SARS-CoV-2 spike and nucleocapsid proteins, and spike peptide-induced release of interferon gamma in whole blood in 51 vaccinated individuals infected with Omicron, in 14 infected with Delta, and in 18 healthy controls. The median time points for the first and second samples were 7 and 14 days after symptom onset, respectively. Findings: Infection with Omicron or Delta led to a rapid and similar increase in antibodies to the SARS-CoV-2 spike and nucleocapsid proteins and spike peptide-induced interferon gamma in whole blood. Both the Omicron and the Delta infected patients had a mild and transient increase in inflammatory parameters. Interpretation: The results suggest that vaccine-induced immunological memory yields similar coverage for the Omicron and Delta variants.


Subject(s)
Hepatitis D , Immune System Diseases
5.
medrxiv; 2022.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2022.01.13.22269213

ABSTRACT

The new SARS-CoV-2 variant of concern (VOC) Omicron has more than 30 mutations in the receptor binding domain (RBD) of the Spike protein enabling viral escape from antibodies in vaccinated individuals and increased transmissibility. It is unclear how vaccine immunity protects against Omicron infection. Here we show that vaccinated participants at a superspreader event had robust recall response of humoral and pre-existing cellular immunity induced by the vaccines, and an emergent de novo T cell response to non-Spike antigens. We compared cases from a Christmas party where 81 of 110 (74%) developed Omicron breakthrough COVID-19, with Delta breakthrough cases and vaccinated non-infected controls. Omicron cases had significantly increased activated SARS-CoV-2 wild type Spike-specific (vaccine) cytotoxic T cells, activated follicular helper (TFH) cells, functional T cell responses, boosted humoral responses, activated anti-Spike plasmablasts and anti-RBD memory B cells compared to controls. Omicron cases had significantly increased de novo memory T cell responses to non-Spike viral antigens compared to Delta breakthrough cases demonstrating development of broad immunity. The rapid release of Spike and RBD-specific IgG+ B cell plasmablasts and memory B cells into circulation suggested affinity maturation of antibodies and that concerted T and B cell immunity may provide durable broad immunity.


Subject(s)
COVID-19
6.
medrxiv; 2021.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2021.10.15.21264977

ABSTRACT

Importance: Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to protect against coronavirus disease of 2019 (COVID-19) is recommended for patients with multiple sclerosis (pwMS). However, approximately 80% of all pwMS treated with anti-CD20 therapy (rituximab, ocrelizumab) or fingolimod have low or absent humoral immunity after vaccination with two doses of SARS-CoV-2 mRNA vaccines. The efficacy and safety of a third vaccine dose in this group is largely unknown. Objective: To characterize the humoral immunogenicity and the safety of a third dose of mRNA-COVID-19 vaccine in anti-CD20- or fingolimod-treated pwMS with low or absent humoral immunity (i.e., anti-SARS-CoV-2 IgG <70 arbitrary units (AU) and <5 AU, respectively) after two vaccinations. Design, setting and participants: 130 anti-CD20- or fingolimod-treated pwMS with low or absent humoral immunity despite full vaccination against SARS-CoV-2, received a third dose of SARS-CoV-2 mRNA vaccine. Humoral immunity (i.e., antibody response against SARS-CoV-2) and the frequency and characteristics of side-effects were analyzed in all participants. Exposures: A third vaccine dose against SARS-CoV-2 with BNT162b2- or mRNA-1273-COVID-19 vaccine. Main outcomes and measures: Patient- and treatment-specific variables were acquired using a digital questionnaire, the Norwegian Immunization Registry and hospital journals. Humoral immunity was assessed by measuring SARS-CoV-2 SPIKE receptor-binding domain (RBD) IgG response. Low/absent humoral immunity was assumed in cases of AU<70 after anti-SPIKE protein-based serology 3-5 weeks after revaccination. Results: A third dose of SARS-CoV-2 mRNA vaccine increased anti-SARS-CoV-2 SPIKE RBD IgG levels significantly. The proportion of patients with assumed protective humoral immunity (anti-SARS-CoV-2 SPIKE RBD IgG > 70 AU) were 25% among patients using anti-CD20 therapy and 7% among those treated with fingolimod. No adverse events were registered during the study period. Conclusion and relevance: A third dose of mRNA-COVID-19 vaccine was associated with significantly increased levels of anti-SARS-CoV-2 SPIKE RBD IgG, and hence assumed protective humoral immunity - in anti-CD20- or fingolimod-treated pwMS with low or absent humoral immunity despite full vaccination. The effect of a third vaccine dose was limited and more prominent among those treated with anti-CD20 therapy.


Subject(s)
Coronavirus Infections , Sclerosis , Multiple Sclerosis , COVID-19
7.
ssrn; 2021.
Preprint in English | PREPRINT-SSRN | ID: ppzbmed-10.2139.ssrn.3792503

ABSTRACT

Most SARS-CoV-2 infected individuals develop symptoms that do not require medical management. We hypothesized that pre-existing cross-reactive T cell responses could protect the majority from severe disease. Here we found that CTL and Th cells specific for seasonal human coronaviruses (HCoV) were significantly expanded in recovered COVID-19 donors and that CTL responses were significantly higher than responses to private SARS-CoV-2 peptides not shared with seasonal HCoV. A third of the SARS-CoV-2 peptide:HLA ligandome was matched by highly similar peptide mimics from seasonal HCoV, constituting a common HCoV peptide pool. CTL immunity was significantly skewed to the common HCoV peptide pool in age groups 20-70y, but not >70y-old donors. Over 40% of recovered donors lacked neutralizing antibodies, highlighting the role of T cell immunity in COVID-19. Results suggest a protective pre-acquired T cell immunity to SARS-CoV-2 and identify epitopes that may help boost vaccine responses and ensure broad protection against this family of viruses.Trial Registration: ClinicalTrials.gov: NCT04320732.Funding: This study was funded by The Health-South East Health Authority (Project 29286), the Research Council of Norway (Project 312693), the Oslo University Hospital, the KG Jebsen Foundation (grant 19), the University of Oslo, The Norwegian Cancer Society.Conflict of Interest: The authors declare that we have no competing interests.


Subject(s)
COVID-19
SELECTION OF CITATIONS
SEARCH DETAIL