A Randomized Controlled Study Assessing Convalescent Immunoglobulins versus Convalescent Plasma for Hospitalized COVID-19 Patients.

BACKGROUND: It is unknown whether convalescent immunoglobulins (cIgG) are better than convalescent plasma (CP) for COVID-19 patients. METHODS: In this randomized trial we assigned high risk COVID-19 with ≤10 days of symptoms, to receive cIgG or CP. The primary endpoint was improvement on day 14 according to the WHO scale. Secondary endpoints were survival on day 14, and improvement, survival, and percent of ventilated patients on day 28 and treatment response in unvaccinated and vaccinated patients. RESULTS: 319 patients were included; 166 received cIgG, and 153 CP. Median age was 64-66 years. 112 patients (67.5%) in the cIgG and 103 patients (67.3%) in the CP group reached the primary endpoint. Difference between groups was 0.1 (95%CI -10.1-10.4, p=0.026), failing to reach non-inferiority. More patients receiving cIgG improved by day 28 [136 patients (81.9%) and 108 patients (70.6%), respectively, 95% CI 1.9-20.7, p<0.001, for superiority p=0.018)]. 17 patients in the cIgG group (10.2%) and 25 patients (16.3%) in the CP group required mechanical ventilation (p=0.136). 16 (9.6%) and 23 (15%) patients respectively died (p=0.172). More unvaccinated patients improved by day 28 in the cIgG group (84.1% vs. 66.1%, p<0.024) and survival was better in the cIgG group (89.9% vs. 77.4% p=0.066). CONCLUSIONS: cIgG failed to reach the primary non-inferiority endpoint on day 14 but was superior to CP on day 28. Survival and improvement by day 28 in unvaccinated patients treated with cIgG were better. In the face of new variants, cIgG is a viable option for treating COVID-19. TRIAL REGISTRATION NUMBER: My Trials MOH_2021-01-14_009667.

Cellular and humoral response to the fourth BNT162b2 mRNA COVID-19 vaccine dose in patients with CLL.

We assessed the humoral and cellular response to the fourth BNT162b2 mRNA COVID-19 vaccine dose in patients with CLL. A total of 67 patients with CLL and 85 age matched controls tested for serologic response and pseudo-neutralization assay. We also tested the functional T-cell response by interferon gamma (IFNγ) to spike protein in 26 patients. Two weeks after the fourth vaccine antibody serologic response was evident in 37 (55.2%) patients with CLL, 20 /22 (91%) of treatment naïve, and 9/32 (28%) patients with ongoing therapy, compared with 100% serologic response in age matched controls. The antibody titer increased by 10-fold in patients with CLL, however, still 88-folds lower than age matched controls. Predictors of better chances of post fourth vaccination serologic response were previous positive serologies after second, third, and pre-fourth vaccination, neutralizing assay, and treatment naïve patients. T-cell response improved from 42.3% before the fourth vaccine to 84.6% 2 weeks afterwards. During the time period of 3 months after the fourth vaccination, 14 patients (21%) developed COVID-19 infection, all recovered uneventfully. Our data demonstrate that fourth SARS-CoV-2 vaccination improves serologic response in patients with CLL to a lesser extent than healthy controls and induces functional T-cell response.

Anti-RBD IgG antibodies and neutralizing antibody levels after the second BNT162b2 dose in patients with plasma cell disorders.

Patients with plasma cell disorders (PCD) are at an increased risk for severe morbidity and mortality due to COVID-19. Recent data have suggested that patients with hematological malignancies, including those with PCD, have suboptimal antibody response to COVID-19 vaccination. We compared the antibody titers of 213 patients with PCD to those of 213 immunocompetent healthcare workers after the second vaccine dose of the BNT162b2 mRNA vaccine. Blood samples were taken 2-4 weeks after the second vaccination and analyzed for anti-receptor binding-domain immunoglobulin G (RBD-IgG) antibodies and neutralizing antibodies (NA). At a median of 20 days after the second vaccine dose, 172 patients (80.8%) developed anti-RBD-IgG antibodies with a geometric mean titer (GMT) of 2.7 (95% confidence interval [CI], 2.4-3.1). In the control group 210 (98.9%) developed anti-RBD-IgG antibodies after a median of 21 days, with a GMT of 5.17 (95%CI, 4.8-5.6), p<0.0001. NA were observed in 151 patients with MM (70.9%) and in 210 controls (98.9%). The GMT of NA in patients with MM and controls was 84.4 (95% CI, 59.0-120.6), and 420.2 (95% CI, 341.4-517.1), respectively (p<0.0001). Multivariable logistic regression revealed that the number of prior therapy lines and age were significant predictors of poor humoral response among patients with MM. Injection site reaction, headache and fatigue were the most common adverse events after vaccination. Adverse events were less common in patients with MM than in controls. In conclusion, a significant percentage of patients with MM developed protecting NA to the BNT162b2 mRNA vaccine, which appears to be safe in this patient population.

The effect of HIV on COVID-19 vaccine responses.

PURPOSE OF REVIEW: Persons living with HIV (PLWH) may have a moderately increased risk of morbidity and mortality from COVID-19 infection, especially if viral load is not controlled and if they are immunosuppressed. Vaccination against SARS-CoV-2 is the most effective measure to prevent morbidity and mortality. However, individuals with HIV/AIDS may have less protection after vaccination. The purpose of this review is to summarize some of the recent studies focused on examining the safety, immunogenicity and effectiveness of anti-SARS-CoV-2 vaccines. RECENT FINDINGS: The safety of all anti-SARS-CoV-2 vaccines among PLWH is not different from the safety of these vaccines among HIV-negative individuals and is acceptable. PLWH with viral suppression and immune reconstitution (CD4 + cell count > 350 cells/µl) may reach almost same immunogenicity such as people without HIV albeit antibody levels and neutralization may decline more rapidly than in people without HIV. PLWH with viremia or immunosuppressed, especially AIDS, have less immunogenicity. SUMMARY: Full vaccination against SARS-CoV-2 is a well tolerated and efficient way to prevent mortality and morbidity from COVID-19 among PLWH and AIDS patients. It is very important to follow recommended booster vaccination for a continuous and prompt immunogenicity.

Association between thrombin generation and clinical characteristics in COVID-19 patients.

INTRODUCTION: COVID-19 disease is associated with coagulopathy and increased risk of thrombosis. An association between thrombin generation (TG) capacity, disease severity and outcomes has not been well described. METHODS: We assessed the correlation of TG with sequential organ failure assessment (SOFA) and sepsis-induced coagulopathy (SIC) scores and clinical outcomes by analysis of plasma samples obtained from hospitalized COVID-19 patients. RESULTS: 32 patients (68.8% male), whose median age was 69 years were assessed, of whom only 3 patients did not receive anticoagulant therapy. D-dimers were uniformly increased. During hospitalization 2 patients suffered thrombosis, 3 experienced bleeding and 12 died. TG parameters from anticoagulated COVID-19 patients did not significantly differ from the values obtained from non-anticoagulated healthy controls. Patients who received higher than prophylactic doses of anticoagulant therapy had increased lag time (P = 0.003), lower endogenous thrombin potential (ETP) (P = 0.037), and a reduced peak height (P = 0.006). ETP correlated with the SIC score (P = 0.038). None of the TG parameters correlated with the SOFA score or were associated with mortality. CONCLUSION: TG was not associated with disease severity among patients hospitalized with COVID-19. However, a correlation between ETP and the SIC score was noted and deserves attention.

Humoral Response to the Fourth BNT162b2 Vaccination and Link Between the Fourth Dose, Omicron Infection, and Disease Severity in Renal Transplant Recipients.

BACKGROUND: The effectiveness of the fourth BNT162b2 vaccination in reducing the rate and severity of coronavirus disease 2019 (COVID-19) caused by the Omicron variant in renal transplant recipients (RTRs) is unknown. METHODS: Interviews were conducted with 447 RTRs regarding the status and timing of the fourth vaccination, prior vaccinations, and preceding COVID-19 infection. RTRs with polymerase chain reaction-confirmed COVID-19 infection from December 1, 2021, to the end of March 2022 were considered to have been infected with the Omicron variant and were interviewed to determine their disease severity. In a subgroup of 74 RTRs, the humoral response to the fourth dose was analyzed. In 30 RTRs, microneutralization assays were performed to reveal the humoral response to wild-type, Delta, and Omicron variant isolates before and after the fourth dose. RESULTS: Of 447 RTRs, 144 (32.2%) were infected with the Omicron variant, with 71 (49.3%) of the infected RTRs having received the fourth vaccine dose. RTRs who did not receive the fourth dose before the infection had more serious illness. In a subgroup of 74 RTRs, the fourth dose elicited a positive humoral response in 94.6% (70/74), with a significant increase in geometric mean titer for receptor-binding domain immunoglobulin G and neutralizing antibodies (P < 0.001). The humoral responses to the Omicron variant before and after the fourth dose were significantly lower than the responses to the wild-type and the Delta variants. CONCLUSION: Overall, the fourth BNT162b2 dose was effective in reducing the rate and severity of Omicron disease in RTRs, despite the reduced humoral response to the variant.

Hospitalized patients with severe COVID-19 during the Omicron wave in Israel - benefits of a fourth vaccine dose.

BACKGROUND: Waning vaccine-immunity and an increased incidence of COVID-19 during the Omicron outbreak led the Israeli Ministry of Health to recommend a fourth dose of BNT162b2 for high-risk individuals. This study assessed the effect of that dose for hospitalized patients with severe/critical, breakthrough COVID-19. METHODS: In this multi-center retrospective cohort study of hospitalized adults with severe/critical COVID-19 in Israel, from 01/15/2022-01/31/2022, cases were divided according to the number of vaccinations received. Poor outcome was defined as mechanical ventilation or in-hospital death, and was compared between 3- and 4-dose vaccinees using logistic regression. RESULTS: Included were 1,049 patients, median age 80 years (IQR 69-87), 51% males. Among them, 394 were unvaccinated, 386 had received 3 doses and 88 4 doses. The 3-dose group was older, had more males and immunosuppression, but with similar outcomes, 49% vs. 51% compared to unvaccinated patients (p = 0.72). Patients after 4 doses were similarly older and immunosuppressed, but had better outcomes compared to unvaccinated patients, 34% vs. 51% (p < 0.01). We examined independent predictors for poor outcome in patients with either 3 or 4 doses, received a median of 161 (IQR 147-168) or 14 (IQR 10-18) days before diagnosis, respectively. Receipt of the fourth dose was associated with protection: OR 0.51 (95%CI 0.3-0.87), as was Remdesivir OR 0.65 (95%CI 0.44-0.96). Male sex, chronic renal failure and dementia were associated with poor outcomes. CONCLUSIONS: Among hospitalized patients with severe/critical breakthrough COVID-19, a recent fourth dose was associated with significant protection against mechanical ventilation or death, compared to three doses.

Phase 1 study of safety, pharmacokinetics, and antiviral activity of SARS-CoV-2 neutralizing monoclonal antibody ABBV-47D11 in patients with COVID-19.

ABBV-47D11 is a neutralizing monoclonal antibody that targets a mutationally conserved hydrophobic pocket distal to the ACE2 binding site of SARS-CoV-2. This first-in-human safety, pharmacokinetics, and antiviral pharmacodynamic assessment in patients with COVID-19 provide an initial evaluation of this antibody that may allow further development. This multicenter, randomized, double-blind, and placebo-controlled single ascending dose study of ABBV-47D11 (180, 600, or 2400 mg) as an intravenous infusion, was in hospitalized and non-hospitalized (confined) adults with mild to moderate COVID-19. Primary outcomes were grade 3 or higher study drug-related adverse events and infusion-related reactions. Secondary outcomes were pharmacokinetic parameters and concentration-time profiles to Day 29, immunogenicity (anti-drug antibodies), and antiviral activity (change in RT-PCR viral load) from baseline to Days 15 and 29. ABBV-47D11 single doses up to 2400 mg were safe and tolerated and no safety signals were identified. The pharmacokinetics of ABBV-47D11 were linear and showed dose-proportional increases in serum concentrations with ascending doses. The exploratory anti-SARS-CoV-2 activity revealed a reduction of viral load at and above the 600 mg dose of ABBV-47D11 regardless of patient demographics and baseline characteristics, however; because of the high inter-individual variability and small sample size a statistical significance was not reached. There is potential for anti-SARS-CoV-2 activity with ABBV-47D11 doses of 600 mg or higher, which could be evaluated in future clinical trials designed and powered to assess viral load reductions and clinical benefit.

First report of myocarditis in two patients with COVID-19 Omicron variant: case report.

Background: Severe acute respiratory syndrome coronavirus 2 infection is responsible for the coronavirus disease 2019 (COVID-19) pandemics. Omicron (B.1.1.529) variant is the cause for the surge of the COVID-19 pandemics of the end of 2021 and the beginning of 2022, although its subvariants are responsible for the following daily increase of COVID-19 cases in July 2022. Early reports of Omicron variant confirmed patients indicated less severe disease course compared with the disease caused by previously encountered variants with absence of data regarding cardiac involvement by Omicron. Case summary: A 42-year-old male who tested positive for Omicron was admitted on January 2022 with chest pain and ST-segment elevation in the inferior leads. Coronary angiography revealed non-significant coronary artery disease. Cardiac magnetic resonance imaging demonstrated features consistent with myocarditis with involvement of 22% of the left ventricular mass by late gadolinium enhancement involving both the lateral and the septal walls. The second patient is a 60-year-old male presented following syncope and palpitations after he was confirmed with Omicron infection. Upon emergency department arrival he had ventricular tachycardia of 250 beats/minute and underwent urgent cardioversion. During his hospitalization, there was no recurrence of malignant arrhythmia, coronary angiography revealed non-obstructive disease. Cardiac magnetic resonance imaging demonstrated imaging features suggesting acute myocarditis with involvement of 19% of the left ventricular mass. Discussion: This is the first report of myocarditis cases as a possible complication associated with Omicron variant. Despite preliminary reports of less severe disease clinicians should be vigilant for potential deleterious cardiac complications of Omicron.

Correlation between Adverse Events and Antibody Titers among Healthcare Workers Vaccinated with BNT162b2 mRNA COVID-19 Vaccine.

Objectives: The BNT162b2 mRNA COVID-19 vaccine has been found to be highly effective in preventing COVID-19 but is associated with increased reactogenicity. We aimed to examine the correlation between immunogenicity and reactogenicity of the BNT162b2 vaccine. Methods: Subjects without prior SARS-CoV-2 infection that participated in active surveillance after being vaccinated with the BNT162b2 vaccine&nbsp;were included. Study participants reported adverse drug reactions (ADRs) through questionnaires administered by text message after receiving each dose of the vaccine. A reactogenicity score was developed based on the type and duration of ADRs. In addition, anti-receptor binding domain (RBD) levels and neutralization assays were performed 7-21 and 7-38 days after the first and second vaccine doses, respectively. Associations between ADRs and antibody levels were assessed by Spearman correlations. Multivariable logistic regression analyses were used to identify factors associated with ADRs. Results: A total of 831 health care workers were included. The mean age was 46.5 years (SD = 11.8) and 75.5% were females. 83.4% and 83.3% had at least one local ADR after the first and second doses, respectively. 33% and 83.2% had at least one systemic ADR after the first and second doses, respectively. Multivariate logistic regression analysis found a significant correlation between ADR score and anti-RBD-IgG titers (r = 0.366; p < 0.0001) after adjustment for age, gender, and days after the second vaccination. High anti-RBD-IgG levels, being younger than 55 and being female, were all correlated with increased rates of ADRs. Conclusion: BNT162b2 mRNA COVID-19 vaccine reactogenicity appears to be correlated with higher post-vaccination antibody levels and is independently associated with younger age and female gender.

Kinetics of cellular and humoral responses to third BNT162B2 COVID-19 vaccine over six months in heart transplant recipients - implications for the omicron variant.

BACKGROUND: The durability of the immune response following the 3-dose BNT162b2 vaccination is unknown. The complexity of the situation is enhanced by the threat that highly transmissible variants may further accelerate the decline in the protection afforded by mRNA vaccines. METHODS: One hundred and three 3-dose-vaccinated heart transplant recipients were longitudinally assessed for the kinetics of variant-specific neutralization (Cohort 1, n = 60) and SARS-CoV-2-specific-T-cell response (Cohort 2, n = 54) over 6 months. Neutralization and T-cell responses were compared between paired samples at 2 time points, using the Kruskal-Wallis test followed by Dunn's multiple comparison test for continuous variables and McNemar's test for dichotomous variables. The Bonferroni method of p values adjustment for multiple comparison was applied. RESULTS: The third dose induced high neutralization of the wild-type virus and delta variant (geometric mean titer [GMT], 137.2 [95% CI, 84.8-221.9] and 80.6, [95% CI, 49.3-132.0], respectively), and to a lesser degree of the omicron variant (GMT, 10.3 [95% CI, 5.9-17.9]). At 6 months, serum neutralizing activity declined but was still high for the wild-type virus and for the delta variant (GMTs 38.1 [95% CI, 21.2-69.4], p = 0.011; and 28.9 [95% CI, 16.6-52.3], p = 0.022, respectively), but not for the omicron variant (GMT 5.9 [95% CI, 3.4-9.8], p = 0.463). The percentages of neutralizing sera against the wild-type virus, delta and omicron variants increased from 70%, 65%, and 38%, before the third dose, to 93% (p < 0.001), 88% (p < 0.001), and 48% (p = 0.021) at 3 weeks after, respectively; and remained high through the 6 months for the wild-type (80%, p = 0.06) and delta (77%, p = 0.102). The third dose induced the development of a sustained SARS-CoV-2-specific-T-cell population, which persisted through 6 months. CONCLUSIONS: The third BNT162b2 dose elicited a durable SARS-CoV-2-specific T-cell response and induced effective and durable neutralization of the wild-type virus and the delta variant, and to a lesser degree of the omicron variant.

Serological response to a third booster dose of BNT162b2 COVID-19 vaccine among seronegative cancer patients.

BACKGROUND AND AIM: The BNT162b2 COVID-19 vaccine (Pfizer/BioNTech), given as a two-dose series, 3 weeks apart, elicits a serological response in 84-98% of patients with cancer, even if administered while undergoing anticancer treatments. Herein, we report the impact of a third (booster) dose of BNT162b2, delivered 6 months following the second vaccine dose. METHODS: This pilot study included four patients with cancer who were seronegative after two vaccine doses, and received a third (booster) dose of BNT162b2 at 6 months following the second vaccine dose. The four patients received the three vaccine doses between December 2020 and July 2021. Samples were evaluated with an enzyme-linked immunosorbent assay (ELISA) that detects IgG (Immunoglobulin G) antibodies against the RBD (receptor-binding domain) of SARS-CoV-2. RESULTS: At a mean time of 19 days (ranges 7-28) after the second vaccination, all four patients were seronegative for RBD-IgG. However, at a mean time of 21 days (ranges 20-22) after the third dose, three out of the four patients (75%) were now seropositive. Mean RBD-IgG titers were increased after the third vaccine dose from 0.37 to 2.81 (Student's t-test, p = 0.05, two-sided). CONCLUSIONS: Although limited by the small sample size, our findings suggest that a third (booster) dose administered to patients with cancer, who remain seronegative despite two doses of BNT162b2, may be efficacious in eliciting an antibody response.

Hospitalised patients with breakthrough COVID-19 following vaccination during two distinct waves in Israel, January to August 2021: a multicentre comparative cohort study.

BackgroundChanging patterns of vaccine breakthrough can clarify vaccine effectiveness.AimTo compare breakthrough infections during a SARS-CoV-2 Delta wave vs unvaccinated inpatients, and an earlier Alpha wave.MethodsIn an observational multicentre cohort study in Israel, hospitalised COVID-19 patients were divided into three cohorts: breakthrough infections in Comirnaty-vaccinated patients (VD; Jun-Aug 2021) and unvaccinated cases during the Delta wave (ND) and breakthrough infections during an earlier Alpha wave (VA; Jan-Apr 2021). Primary outcome was death or ventilation.ResultsWe included 343 VD, 162 ND and 172 VA patients. VD were more likely older (OR: 1.06; 95% CI: 1.05-1.08), men (OR: 1.6; 95% CI: 1.0-2.5) and immunosuppressed (OR: 2.5; 95% CI: 1.1-5.5) vs ND. Median time between second vaccine dose and admission was 179 days (IQR: 166-187) in VD vs 41 days (IQR: 28-57.5) in VA. VD patients were less likely to be men (OR: 0.6; 95% CI: 0.4-0.9), immunosuppressed (OR: 0.3; 95% CI: 0.2-0.5) or have congestive heart failure (OR: 0.6; 95% CI: 0.3-0.9) vs VA. The outcome was similar between all cohorts and affected by age and immunosuppression and not by vaccination, variant or time from vaccination.ConclusionsVaccination was protective during the Delta variant wave, as suggested by older age and greater immunosuppression in vaccinated breakthrough vs unvaccinated inpatients. Nevertheless, compared with an earlier post-vaccination period, breakthrough infections 6 months post-vaccination occurred in healthier patients. Thus, waning immunity increased vulnerability during the Delta wave, which suggests boosters as a countermeasure.

A Practical Clinical Score Predicting Respiratory Failure in COVID-19 Patients.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic resulted in repeated surges of patients, sometimes challenging triage protocols and appropriate control of patient flow. Available models, such as the National Early Warning Score (NEWS), have shown significant limitations. Still, they are used by some centers to triage COVID-19 patients due to the lack of better tools. OBJECTIVES: To establish a practical and automated triage tool based on readily available clinical data to rapidly determine a distinction between patients who are prone to respiratory failure. METHODS: The electronic medical records of COVID-19 patients admitted to the Sheba Medical Center March-April 2020 were analyzed. Population data extraction and exploration were conducted using a MDClone (Israel) big data platform. Patients were divided into three groups: non-intubated, intubated within 24 hours, and intubated after 24 hours. The NEWS and our model where applied to all three groups and a best fit prediction model for the prediction of respiratory failure was established. RESULTS: The cohort included 385 patients, 42 of whom were eventually intubated, 15 within 24 hours or less. The NEWS score was significantly lower for the non-intubated patients compared to the two other groups. Our improved model, which included NEWS elements combined with other clinical data elements, showed significantly better performance. The model's receiver operating characteristic curve had area under curve (AUC) of 0.92 with of sensitivity 0.81, specificity 0.89, and negative predictive value (NPV) 98.4% compared to AUC of 0.63 with NEWS. As patients deteriorate and require further support with supplemental O2, the need for re-triage emerges. Our model was able to identify those patients on supplementary O2 prone to respiratory failure with an AUC of 0.86 sensitivity 0.95, and specificity 0.7 NPV 98.9%, whereas NEWS had an AUC of 0.76. For both groups positive predictive value was approximately 35. CONCLUSIONS: Our model, based on readily available and simple clinical parameters, showed an excellent ability to predict negative outcome among patients with COVID-19 and therefore might be used as an initial screening tool for patient triage in emergency departments and other COVID-19 specific areas of the hospital.

Fourth BNT162b2 vaccination neutralization of omicron infection after heart transplantation.

We investigated changes in receptor-binding domain IgG and neutralizing antibodies against the omicron and delta variants, vs the wild-type virus, in response to a fourth BNT162b2 dose in 90 heart transplant (HT) recipients. The fourth dose induced anti-RBD IgG antibodies and a higher neutralization efficiency against the wild-type virus and the variants; however, neutralization efficiency against the omicron variant was lower than that against the delta variant (the latter demonstrating efficacy similar to that against the wild-type virus). Notably, while IgG anti-RBD antibodies were detectable in >80% of the HT recipients, only about half demonstrated neutralization efficiency against the omicron variant. A SARS-CoV-2-specific-T-cell response following the fourth dose was evident in the majority of transplant recipients. Boosting vulnerable groups improves antibody responses (including neutralizing responses) and cellular immunity, but the incomplete immunological response, particularly for omicron, suggests continued preventive measures and optimization of vaccination strategies that elicit strong, and long-lasting immune responses, in this high-risk population, should remain a priority.

Seropositivity and neutralising antibodies at six months after BNT162b2 vaccination in patients with solid tumours.

AIM: Patients with cancer are at an increased risk for severe coronavirus disease of 2019. We previously reported initial findings from a single centre prospective study evaluating antibody response after BNT162b2 vaccine, showing that adequate antibody response was achieved after two doses, but not after one, in patients with cancer vaccinated during anticancer therapy. Herein, we report a follow-up study, evaluating antibody response six months after the second vaccine dose. METHODS: The study included patients with solid tumours undergoing anticancer treatment, and immunocompetent health-care workers serving as controls. Serum titres of the receptor-binding domain (RBD) IgG and neutralising antibodies (Nabs) were measured approximately six months after the second vaccine dose. Complete blood count values were collected and evaluated as predictors for antibody response. RESULTS: The analysis included 93 patients with cancer (66.7% metastatic). Six months after the second vaccine dose (mean 176 ± 20 days), seropositivity rate among patients and controls was 83.9% versus 96.3% (p = 0.0001), respectively. Median RBD-IgG titre was lower among patients compared with controls (2.3 versus 3.2, p = 0.0002). Among seropositive individuals, median Nabs titre was similar between patients with cancer and controls (p = 0.566). Among patients with cancer, lymphocyte and neutrophil counts were not correlated with either RBD-IgG or Nabs titres. CONCLUSIONS: Seropositivity rates and RBD-IgG titre at six months after second BNT162b2 vaccine dose are lower among patients with cancer compared with healthy controls. However, Nabs titre is similar, suggesting a comparable protection among seropositive individuals. Lymphocyte count is not predictive of antibody response.

A third dose of the BNT162b2 mRNA vaccine significantly improves immune responses among liver transplant recipients.

BACKGROUND & AIMS: Immune responses of solid organ transplant recipients to 2 doses of the BNT162b2 mRNA anti-SARS-CoV-2 vaccine are impaired. The immunogenicity and safety of a third dose among liver transplant (LT) recipients are unknown. This work aimed to evaluate the immune response of LT recipients to a third dose of the BNT162b2 mRNA vaccine. METHODS: Consecutive LT recipients (n = 61) in follow-up at Sheba Medical Center were included. Receptor binding domain (RBD) IgG, neutralizing antibody (NA) titers, and T-cell levels before and 21-28 days after a third vaccine dose were determined. Adverse effects after the third dose were monitored. RESULTS: The median age of LT recipients was 65 years and 57.4% were male. The humoral immune response rate improved significantly, with 56% of patients showing a response before the third vaccine dose compared to 98% after the third dose. The cellular response in 12 evaluated patients improved significantly (p = 0.008). The geometric mean of anti-RBD IgG levels, NA levels, and T-cell count also increased significantly after the third dose. NA titers after the third dose negatively correlated with age (p = 0.03), mycophenolate mofetil treatment (p = 0.005), and combined immunosuppression as opposed to calcineurin inhibitor monotherapy (p = 0.001). After the third dose, adverse effects were reported by 37% of recipients and were mostly mild (local pain and fatigue). CONCLUSION: After a third BNT162b2 mRNA vaccine, the immune response improved significantly among LT recipients, without serious adverse effects. Further studies are needed to evaluate immune response durability and to determine the optimal number and schedule of booster vaccine doses. LAY SUMMARY: The Pfizer-Biotech BNT162b2SARS-CoV-2 vaccine induced significant immunity among liver transplant recipients after a third dose. The majority of the patients developed sufficient levels of both humoral and cellular immune responses. Factors that predict non-response were older age and immunosuppressive medications.