Project description:BackgroundTo minimize COVID-19 pandemic burden and spread, 3-dose vaccination campaigns commenced worldwide. Since patients who are pregnant are at increased risk for severe disease, they were recently included in that policy, despite the lack of available evidence regarding the impact of a third boosting dose during pregnancy, underscoring the urgent need for relevant data. We aimed to characterize the effect of the third boosting dose of mRNA Pfizer BNT162b2 vaccine in pregnancy.MethodsWe performed a prospective cohort study of anti-SARS-CoV-2 antibody titers (n = 213) upon delivery in maternal and cord blood of naive fully vaccinated parturients who received a third dose (n = 86) as compared with 2-dose recipients (n = 127).ResultsWe found a robust surge in maternal and cord blood levels of anti-SARS-CoV-2 titers at the time of delivery, when comparing pregnancies in which the mother received a third boosting dose with 2-dose recipients. The effect of the third boosting dose remained significant when controlling for the trimester of last exposure, suggesting additive immunity extends beyond that obtained after the second dose. Milder side effects were reported following the third dose, as compared with the second vaccine dose, among the fully vaccinated group.ConclusionThe third boosting dose of mRNA Pfizer BNT162b2 vaccine augmented maternal and neonatal immunity with mild side effects. These data provide evidence to bolster clinical and public health guidance, reassure patients, and increase vaccine uptake among patients who are pregnant.FundingIsrael Science Foundation KillCorona grant 3777/19; Research grant from the "Ofek" Program of the Hadassah Medical Center.
Project description:BackgroundPatients with B-cell lymphoma are a fragile category of subjects, particularly exposed to infections and characterized by an impaired vaccination response due to the disease itself and, even more, to the chemotherapy regimen. For this reason, extensive knowledge of the immune response status of these subjects is of fundamental importance to obtain possible indications for a tailored immunization strategy.MethodsWe enrolled two cohorts of patients with B-cell lymphoma under rituximab treatment or 3-24 months after treatment. In all patients, we evaluated both humoral and cellular immunological memory toward SARS-CoV-2, after standard vaccination and upon one booster dose.ResultsWe observed no Spike-specific IgG production in patients (n = 25) under anti-CD20 treatment, whereas patients (n = 16) vaccinated after the completion of chemotherapy showed a higher humoral response. Evaluating SARS-CoV-2-specific T-cell response, we found that patients in both cohorts had developed robust cellular immunity after vaccination. Of the 21 patients (51%) that experienced a breakthrough SARS-CoV-2 infection, only six patients developed severe disease. Interestingly, these six patients had all been treated with rituximab plus bendamustine. Notably, we observed that Spike-specific IgG levels in patients treated with rituximab plus bendamustine were absent or lower compared with those in patients treated with rituximab plus other chemotherapy, whereas Spike-specific T-cell response was not different based on chemotherapy regiment.DiscussionOur results show that, in patients with B-cell lymphoma under rituximab therapy, anti-SARS-CoV-2 mRNA vaccination induces a weak or absent humoral response but a consistent T-cell response. In addition, chemotherapy regimens with bendamustine further reduce patients' ability to mount a Spike-specific humoral response even after a long time period from chemotherapy discontinuation. These results provide evidence that different chemotherapeutics display different immunosuppressive properties that could be taken in to account in the choice of the right drug regimen for the right patient. Moreover, they question whether immunocompromised patients, particularly those treated with bendamustine, need interventions to improve vaccine-induced immune response.
Project description:IntroductionSARS-CoV-2 vaccination is the leading strategy to prevent severe courses after SARS-CoV-2 infection. In our study, we analyzed humoral and cellular immune responses in detail to three consecutive homologous or heterologous SARS-CoV-2 vaccinations and breakthrough infections.MethodsPeripheral blood samples of n=20 individuals were analyzed in the time course of three SARS-CoV-2 vaccinations and/or breakthrough infection. S1-, RBD-, S2- and N-specific IgG antibodies were quantified using Luminex-based multiplex assays and electrochemiluminescence multiplex assays for surrogate neutralization in plasma. Changes in cellular immune components were determined via flow cytometry of whole blood samples.ResultsAll individuals (n=20) responded to vaccination with increasing S1-/RBD-/S2-specific IgG levels, whereas specific plasma IgA displayed individual variability. The third dose increased antibody inhibitory capacity (AIC) against immune-escape variants Beta and Omicron BA.1 independently of age. The mRNA-primed vaccination induced IgG and IgA immunity more efficiently, whereas vector-primed individuals displayed higher levels of memory T and B cells. Vaccinees showed SARS-CoV-2-specific T cell responses, which were further improved and specified after Omicron breakthrough infections in parallel to the appearance of new variant-specific antibodies.DiscussionIn conclusion, the third vaccination was essential to increase IgG levels, mandatory to boost AIC against immune-escape variants, and induced SARS-CoV-2-specific T cells. Breakthrough infection with Omicron generates additional spike specificities covering all known variants.
Project description:ObjectivePatients with autoimmune inflammatory rheumatic diseases receiving rituximab (RTX) therapy are at higher risk of poor COVID-19 outcomes and show substantially impaired humoral immune response to anti-SARS-CoV-2 vaccine. However, the complex relationship between antigen-specific B cells and T cells and the level of B cell repopulation necessary to achieve anti-vaccine responses remain largely unknown.MethodsAntibody responses to SARS-CoV-2 vaccines and induction of antigen-specific B and CD4/CD8 T cell subsets were studied in 19 patients with rheumatoid arthritis (RA) or antineutrophil cytoplasmic antibody-associated vasculitis receiving RTX, 12 patients with RA receiving other therapies, and 30 healthy controls after SARS-CoV-2 vaccination with either messenger RNA or vector-based vaccines.ResultsA minimum of 10 B cells per microliter (0.4% of lymphocytes) in the peripheral circulation appeared to be required for RTX-treated patients to mount seroconversion to anti-S1 IgG upon SARS-CoV-2 vaccination. RTX-treated patients who lacked IgG seroconversion showed reduced receptor-binding domain-positive B cells (P = 0.0005), a lower frequency of Tfh-like cells (P = 0.0481), as well as fewer activated CD4 (P = 0.0036) and CD8 T cells (P = 0.0308) compared to RTX-treated patients who achieved IgG seroconversion. Functionally relevant B cell depletion resulted in impaired interferon-γ secretion by spike-specific CD4 T cells (P = 0.0112, r = 0.5342). In contrast, antigen-specific CD8 T cells were reduced in both RA patients and RTX-treated patients, independently of IgG formation.ConclusionIn RTX-treated patients, a minimum of 10 B cells per microliter in the peripheral circulation is a candidate biomarker for a high likelihood of an appropriate cellular and humoral response after SARS-CoV-2 vaccination. Mechanistically, the data emphasize the crucial role of costimulatory B cell functions for the proper induction of CD4 responses propagating vaccine-specific B cell and plasma cell differentiation.
Project description:Patients treated with B-cell-targeting therapies like Rituximab or Ibrutinib have decreased serological response to various vaccines. In this study, we tested serological and cellular response to SARS-CoV-2 mRNA vaccines in 16 patients treated with Ibrutinib, 16 treated with maintenance Rituximab, 18 patients with chronic lymphocytic leukaemia (CLL) with watch and wait status and 21 healthy volunteers. In comparison with the healthy volunteers, where serological response was achieved by 100% subjects, patients on B-cell-targeting therapy (Ibrutinib and Rituximab) had their response dramatically impaired. The serological response was achieved in 0% of Rituximab treated, 18% of Ibrutinib treated and 50% of untreated CLL patients. Cell-mediated immunity analysed by the whole blood Interferon-γ Release immune Assay developed in 80% of healthy controls, 62% of Rituximab treated, 75% of Ibrutinib treated and 55% of untreated CLL patients. The probability of cell-mediated immune response development negatively correlates with disease burden mainly in CLL patients. Our study shows that even though the serological response to SARS-CoV-2 vaccine is severely impaired in patients treated with B-cell-targeting therapy, the majority of these patients develop sufficient cell-mediated immunity. The vaccination of these patients therefore might be meaningful in terms of protection against SARS-CoV-2 infection.
Project description:IntroductionRubella virus (RV) was eliminated in the United States in 2004, although a small portion of the population fails to develop long-term immunity against RV even after two doses of the measles-mumps-rubella (MMR) vaccine. We hypothesized that inherent biological differences in cytokine and chemokine signaling likely govern an individual's response to a third dose of the vaccine.MethodsHealthy young women (n = 97) were selected as study participants if they had either low or high extremes of RV-specific antibody titer after two previous doses of MMR vaccine. We measured cytokine and chemokine secretion from RV-stimulated PBMCs before and 28 days after they received a third dose of MMR vaccine and assessed correlations with humoral immune response outcomes.ResultsHigh and low antibody vaccine responders exhibited a strong pro-inflammatory cellular response, with an underlying Th1-associated signature (IL-2, IFN-γ, MIP-1β, IP-10) and suppressed production of most Th2-associated cytokines (IL-4, IL-10, IL-13). IL-10 and IL-4 exhibited significant negative associations with neutralizing antibody titers and memory B cell ELISpot responses among low vaccine responders.ConclusionIL-4 and IL-10 signaling pathways may be potential targets for understanding and improving the immune response to rubella vaccination or for designing new vaccines that induce more durable immunity.
Project description:The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has severely impacted on public health, mainly on immunosuppressed patients, including solid organ transplant recipients. Vaccination represents a valuable tool for the prevention of severe SARS-CoV-2 infection, and the immunogenicity of mRNA vaccines has been evaluated in transplanted patients. In this study, we investigated the role of a third dose of the BNT162b2 vaccine in a cohort of kidney transplant recipients, analyzing both humoral and cell-mediated responses. We observed an increased immune response after the third dose of the vaccine, especially in terms of Spike-specific T cell response. The level of seroconversion remained lower than 50% even after the administration of the third dose. Mycophenolate treatment, steroid administration and age seemed to be associated with a poor immune response. In our cohort, 11/45 patients experienced a SARS-CoV-2 infection after the third vaccine dose. HLA antibodies appearance was recorded in 7 out 45 (15.5%) patients, but none of the patients developed acute renal rejection. Further studies for the evaluation of long-term immune responses are still ongoing, and the impact of a fourth dose of the vaccine will be evaluated.