Project description:Patients with chronic lymphocytic leukemia (CLL) are at a high risk for infections caused by Streptococcus pneumoniae. A pneumococcal conjugate vaccine (PCV) can induce a significant antibody response for some CLL patients. In this study we investigated antibody persistence after PCV7 in patients with CLL. The study material comprised 24 patients with CLL and 8 immunocompetent controls. The median antibody concentrations five years after PCV7 were lower for six pneumococcal serotypes in patients with CLL compared to controls, but the difference was not statistically significant. Depending on the serotype, the percentage of the CLL patients with antibody levels suggested to provide protection against invasive pneumococcal disease (IPD) varied from 29 to 71% five years after vaccination. This data suggests that PCV could result in antibody persistence at least five years in CLL patients.
Project description:Patients with chronic lymphocytic leukemia (CLL) have an increased risk for severe COVID-19 disease and mortality. The goal of this study was to determine the efficacy of COVID-19 vaccine in patients with CLL. We evaluated humoral immune responses to the BNT162b2 messenger RNA (mRNA) COVID-19 vaccine in patients with CLL and compared responses with those obtained in age-matched healthy control subjects. Patients received 2 vaccine doses, 21 days apart, and antibody titers were measured by using the Elecsys Anti-SARS-CoV-2 S assay after administration of the second dose. In a total of 167 patients with CLL, the antibody response rate was 39.5%. A comparison between 52 patients with CLL and 52 sex- and aged-matched healthy control subjects revealed a significantly reduced response rate among patients (52% vs 100%, respectively; adjusted odds ratio, 0.010; 95% confidence interval, 0.001-0.162; P < .001). The response rate was highest in patients who obtained clinical remission after treatment (79.2%), followed by 55.2% in treatment-naive patients and 16.0% in patients under treatment at the time of vaccination. In patients treated with either Bruton's tyrosine kinase inhibitors or venetoclax ± anti-CD20 antibody, response rates were considerably low (16.0% and 13.6%). None of the patients exposed to anti-CD20 antibodies <12 months before vaccination responded. In a multivariate analysis, the independent predictors of response were younger age, female sex, lack of currently active treatment, immunoglobulin G levels ≥550 mg/dL, and immunoglobulin M levels ≥40 mg/dL. In conclusion, antibody-mediated response to the BNT162b2 mRNA COVID-19 vaccine in patients with CLL is markedly impaired and affected by disease activity and treatment. This trial was registered at www.clinicaltrials.gov as #NCT04746092.
Project description:Several studies reported on the humoral response in subjects having received the BNT162b2 mRNA COVID-19 vaccine. However, data on the kinetics of antibodies 3 months post-vaccination are currently lacking and are important to drive the future vaccination strategy. The CRO-VAX HCP study is an ongoing multicentre, prospective and interventional study designed to assess the antibody response in a population of healthcare professionals who had received two doses of the BNT162b2 mRNA COVID-19 vaccine. Two hundred individuals underwent a blood drawn within 2 days before the first vaccine dose. One-hundred and forty-two persons (71%) were categorized as seronegative at baseline while 58 (29%) were seropositive. Samples were then collected after 14, 28, 42, 56, and 90 days. Antibodies against the SARS-CoV-2 nucleocapsid and the receptor binding domain of the S1 subunit of the spike protein were measured in all individuals at different time points. Using a one-compartment kinetics model, the time to maximum concentration was estimated at 36 ± 3 days after the first dose and the estimated half-life of antibodies was 55 days (95% CI: 37-107 days) in seronegative participants. In seropositive participants, the time to maximum concentration was estimated at 24 ± 4 days and the estimated half-life was 80 days (95% CI: 46-303 days). The antibody response was higher in seropositive compared to seronegative participants. In both seropositive and seronegative subjects, a significant antibody decline was observed at 3 months compared to the peak response. Nevertheless, the humoral response remained robust in all participants.
Project description:Immunocompromised individuals such as patients with chronic lymphocytic leukemia (CLL) are at risk of impaired immune responses to vaccination. The objective of our study was to evaluate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibody responses in patients with CLL after the first, second, and third doses of the BNT162b2 or mRNA-1273 vaccines and after a single dose for patients with confirmed previous COVID-19. In all, 530 patients were included in the study. Patients received 2 doses at a 4-week interval and a third dose if they were seronegative after the second dose. Response rate was 27% after dose 1 and 52% after dose 2. Post-dose 2 treatment-naïve patients had the highest response rate (72%) followed by patients previously treated by chemoimmunotherapy (60%). Among patients receiving therapy, those receiving Bruton tyrosine kinase inhibitor alone (22%) or in combination with anti-CD20 monoclonal antibodies or venetoclax (0%) had the poorer response rate whereas patients who received venetoclax monotherapy achieved a significantly higher response rate (52%). A multivariable analysis identified age older than 65 years, ongoing CLL treatment, and gamma globulin ≤6 g/L as independent predictors of the absence of seroconversion. Post-dose 2 seronegative patients had a global response rate of 35% after dose 3. This study provides an argument for the use of a third dose and for prophylactic SARS-CoV-2 neutralizing monoclonal antibodies.
Project description:The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has raised concern about increased transmissibility, infectivity, and immune evasion from a vaccine and infection-induced immune responses. Although COVID-19 mRNA vaccines have proven to be highly effective against severe COVID-19 disease, the decrease in vaccine efficacy against emerged Beta and Delta variants emphasizes the need for constant monitoring of new virus lineages and studies on the persistence of vaccine-induced neutralizing antibodies. To analyze the dynamics of COVID-19 mRNA vaccine-induced antibody responses, we followed 52 health care workers in Finland for 6 months after receiving two doses of BNT162b2 vaccine with a 3-week interval. We demonstrate that, although anti-S1 antibody levels decrease 2.3-fold compared to peak antibody levels, anti-SARS-CoV-2 antibodies persist for months after BNT162b2 vaccination. Variants D614G, Alpha, and Eta are neutralized by sera of 100% of vaccinees, whereas neutralization of Delta is 3.8-fold reduced and neutralization of Beta is 5.8-fold reduced compared to D614G. Despite this reduction, 85% of sera collected 6 months postvaccination neutralizes Delta variant. IMPORTANCE A decrease in vaccine efficacy against emerging SARS-CoV-2 variants has increased the importance of assessing the persistence of SARS-CoV-2 spike protein-specific antibodies and neutralizing antibodies. Our data show that after 6 months post two doses of BNT162b2 vaccine, antibody levels decrease yet remain detectable and capable of neutralizing emerging variants. By monitoring the vaccine-induced antibody responses, vaccination strategies and administration of booster doses can be optimized.
Project description:The emergence of the Omicron variant has generated concerns about the efficacy of COVID-19 vaccines. We evaluated the serum neutralizing activity of antibodies against the Omicron (lineage BA.1.1) by plaque reduction neutralizing test, as well as its correlation with age and gender, in a Colombian cohort six months after being vaccinated with BNT162b2 (Pfizer/BioNTech). Compared to all other variants analyzed, a significantly lower neutralizing activity (p<0.001) was observed against Omicron. Interestingly, older individuals exhibited lower titers against Omicron than those younger than 40. No statistical differences in neutralizing activity were observed according to gender. Our results showed that two doses of BNT162b2 might not provide robust protection against the Omicron variant over time. It is necessary to consider including changes in the composition of the vaccines to protect against new emerging variants of SARS-CoV-2 and campaigns to implement additional booster vaccinations.
Project description:BackgroundThe emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and the persistence of the pandemic, even with mass coronavirus disease 2019 (COVID-19) vaccination, have raised questions about the durability of immunity and extent of cross-reactive immunity after vaccination. This study aimed to characterize the humoral and cellular immune response to the mRNA-1273 vaccine using a prospective longitudinal cohort.MethodsWe recruited 177 young SARS-CoV-2 infection-naive adults. Two doses of mRNA-1273 vaccine were administered at 28-day intervals, and blood samples were collected at five time points: pre-vaccination (T0), 4 weeks after the first (T1) and second dose (T2), and 3 months (T3) and 6 months (T4) after the first dose. Anti-SARS-CoV-2 spike protein (anti-S) IgG antibody, neutralizing antibody, and T-cell immune responses were evaluated.ResultsThe two-dose mRNA-1273 vaccination induced robust anti-SARS-CoV-2 antibody responses, which remained higher than the titers at T1 until T4. A higher peak anti-S antibody titer at T2 was associated with better cross-reactive immunity against Delta and Omicron variants and long-lasting (anti-S IgG and neutralizing antibody) humoral immunity up to T4. The overall T-cell immune response was not correlated with peak antibody titers (T-lymphocyte subpopulation analysis was not performed).ConclusionThis study showed that an early strong antibody response is predictive of longer humoral immunity and better cross-reactive neutralizing immunity against Delta and Omicron variants.