Immunogenicity of a Third Dose of BNT162b2 Vaccine among Lung Transplant Recipients-A Prospective Cohort Study.

Two doses of mRNA SARS-CoV-2 vaccines elicit an attenuated humoral immune response among immunocompromised patients. Our study aimed to assess the immunogenicity of a third dose of the BNT162b2 vaccine among lung transplant recipients (LTRs). We prospectively evaluated the humoral response by measuring anti-spike SARS-CoV-2 and neutralizing antibodies in 139 vaccinated LTRs ~4-6 weeks following the third vaccine dose. The t-cell response was evaluated by IFNγ assay. The primary outcome was the seropositivity rate following the third vaccine dose. Secondary outcomes included: positive neutralizing antibody and cellular immune response rate, adverse events, and COVID-19 infections. Results were compared to a control group of 41 healthcare workers. Among LTRs, 42.4% had a seropositive antibody titer, and 17.2% had a positive t-cell response. Seropositivity was associated with younger age (t = 3.736, p < 0.001), higher GFR (t = 2.355, p = 0.011), and longer duration from transplantation (t = -1.992, p = 0.024). Antibody titer positively correlated with neutralizing antibodies (r = 0.955, p < 0.001). The current study may suggest the enhancement of immunogenicity by using booster doses. Since monoclonal antibodies have limited effectiveness against prevalent sub-variants and LTRs are prone to severe COVID-19 morbidity, vaccination remains crucial for this vulnerable population.

Improved immunogenicity following the third dose of BNT162b2 mRNA vaccine in heart transplant recipients.

OBJECTIVES: The immunogenicity of two-dose severe acute respiratory syndrome coronavirus 2 vaccine is lower among heart transplant (HTx) recipients, compared with the general population. Our aim was to assess the immunogenicity of a third-dose vaccine in HTx recipients. METHODS: This is a prospective cohort study of HTx recipients who received a third dose of the BNT162b2 vaccine. Immunogenicity was assessed by serum levels of anti-spike immunoglobulin G (S-IgG), taken at baseline and 14-28 days after the third dose. Titres above 50 U/ml were interpreted positive. RESULTS: We Included 42 HTx recipients at a median age of 65 years [interquartile range (IQR) 58-70]. At baseline, the median of 27 days (IQR 13-42) before the third dose and the median titre of the whole group was 18 U/ml (IQR 4-130). Only 14 patients (33%) were S-IgG seropositive. After the third dose, the proportion of seropositive patients increased significantly to 57% (P = 0.05) and the median titre increased significantly to 633 U/ml (IQR 7-6104, P < 0.0001). Younger age at HTx (OR per 1-year decrease 1.07, P = 0.05), low tacrolimus serum level (OR per 1-unit decrease 2.28, P = 0.02), mammalian target of rapamycin use (OR 13.3, P = 0.003), lack of oral steroids use (OR 4.17, P = 0.04) and lack of calcineurin inhibitor use (71% of responders vs 100% non-responders received calcineurin inhibitors, P = 0.01) were predictors of seropositive result after the third dose. However, no significant association was detected following adjustment for baseline S-IgG titre. CONCLUSIONS: Third-dose booster of BNT162b2 vaccine significantly increased immunogenicity among HTx recipients who previously received a two-dose vaccine.

Anti-TNFα Treatment Impairs Long-Term Immune Responses to COVID-19 mRNA Vaccine in Patients with Inflammatory Bowel Diseases.

Patients with inflammatory bowel disease (IBD) treated with anti-tumor-necrosis factor-alpha (TNFα) exhibited lower serologic responses one-month following the second dose of the COVID-19 BNT162b2 vaccine compared to those not treated with anti-TNFα (non-anti-TNFα) or to healthy controls (HCs). We comprehensively analyzed long-term humoral responses, including anti-spike (S) antibodies, serum inhibition, neutralization, cross-reactivity and circulating B cell six months post BNT162b2, in patients with IBD stratified by therapy compared to HCs. Subjects enrolled in a prospective, controlled, multi-center Israeli study received two BNT162b2 doses. Anti-S levels, functional activity, specific B cells, antigen cross-reactivity, anti-nucleocapsid levels, adverse events and IBD disease score were detected longitudinally. In total, 240 subjects, 151 with IBD (94 not treated with anti-TNFα and 57 treated with anti-TNFα) and 89 HCs participated. Six months after vaccination, patients with IBD treated with anti-TNFα had significantly impaired BNT162b2 responses, specifically, more seronegativity, decreased specific circulating B cells and cross-reactivity compared to patients untreated with anti-TNFα. Importantly, all seronegative subjects were patients with IBD; of those, >90% were treated with anti-TNFα. Finally, IBD activity was unaffected by BNT162b2. Altogether these data support the earlier booster dose administration in these patients.

Humoral response among patients with interstitial lung disease vaccinated with the BNT162b2 SARS-Cov-2 vaccine: a prospective cohort study.

BACKGROUND: Patients with interstitial lung disease (ILD) are at high risk of severe COVID-19 infection. Additionally, their anti-inflammatory and antifibrotic treatment may cause immunosuppression. Nevertheless, their ability to mount an adequate immune response to messenger RNA SARS-CoV-2 vaccines was not evaluated. Therefore, we aimed to evaluate the humoral response after the BNT162b2 vaccine among idiopathic pulmonary fibrosis (IPF) patients treated with antifibrotic therapy and among non-IPF ILD patients treated with anti-inflammatory therapy. METHODS: We conducted an observational prospective cohort study to evaluate the level of anti-spike (S-IgG) antibodies after two doses of the BNT162b2 vaccine in patients with ILD. The cohort included 40 patients with idiopathic pulmonary fibrosis (IPF) treated with anti-fibrotic therapy and 29 patients with non-IPF ILD treated with anti-inflammatory therapy. For S-IgG titer measurement, one serology test was drawn from all patients 4-6 months after the second vaccine dose. In addition a control group matched for age and sex was created from a healthy control cohort of 107 patients. The study was conducted in Rabin Medical Center (Israel) between June and August 2021. RESULTS: All patients in the anti-fibrotic arm were seropositive (40/40), corresponding to the matched control group (P = 1.0). The anti-fibrotic arm had a significantly lower median antibody titer in comparison to the matched control group (361.10 [IQR, 207-811] AU/ml vs. 820.75 [IQR, 459-1313] AU/ml; P < 0.001). Only 48.3% (14/29) of patients in the anti-inflammatory arm were seropositive in comparison to 100% (29/29) in the healthy control group (P < 0.001). The anti-inflammatory arm had a significantly lower median antibody titer in comparison to the healthy control group (39.6 [IQR, 4.25-165] AU/ml vs. 970.1 [IQR, 505-1926] AU/ml; P < 0.001). CONCLUSION: IPF patients treated with antifibrotic therapy mount an adequate immune response after 2 doses of the BNT162b2 vaccine, and maintain a 100% seropositivity rate 4-6 months after vaccination. However, their antibody titer was reduced in comparison to a healthy control group. Among patients with non-IPF ILD treated with anti-inflammatory therapy, 48% were seronegative 4-6 months after the second vaccine dose. Moreover, treatment with rituximab caused significant immunosuppression, even in comparison to other anti-inflammatory treatments.

Three-month follow-up of durability of response to the third dose of the SARS-CoV-2 BNT162b2 vaccine in adults aged 60 years and older: a prospective cohort study.

OBJECTIVE: To evaluate the durability of response 3 months after the third BNT162b2 vaccine in adults aged 60 years and older. DESIGN: Prospective cohort study. SETTING: Single tertiary centre. PARTICIPANTS: Healthcare workers/family members aged ≥60 years old who received the third BNT162b2 dose. INTERVENTIONS: Blood samples were drawn immediately before (T0), 10-19 days (T1) and 74-103 days (T2) after the third dose. PRIMARY AND SECONDARY OUTCOME MEASURES: Anti-spike IgG titres were determined using a commercial assay and seropositivity was defined as ≥50 arbitrary units (AU)/mL. Neutralising antibody titres were determined at T2. Adverse events, COVID-19 infections and Clinical Frailty Scale (CFS) levels were documented. RESULTS: The analysis included 97 participants (median age, 70 years (IQR, 66-74), 58% CFS level 2). IgG titres, which increased significantly from T0 to T1 (median, 440 AU/mL (IQR, 294-923) and median, 25 429 AU/mL (IQR, 14 203-36 114), respectively; p<0.001), decreased significantly by T2, but all remained seropositive (median, 8306 AU/mL (IQR, 4595-14 701), p<0.001 vs T1). In a multivariable analysis, only time from the second vaccine was significantly associated with lower IgG levels at T2 (p=0.017). At T2, 60 patients were evaluated for neutralising antibodies; all were seropositive (median, 1294 antibody titres; IQR, 848-2072). Neutralising antibody and anti-spike IgG levels were correlated (r=0.6, p<0.001). No major adverse events or COVID-19 infections were reported. CONCLUSIONS: Anti-spike IgG and neutralising antibody levels remain adequate 3 months after the third BNT162b2 vaccine in healthy adults aged ≥60 years, although the decline in IgG is concerning. A third dose of vaccine in this population should be top priority.

Immunosuppression reduction when administering a booster dose of the BNT162b2 mRNA SARS-CoV-2 vaccine in kidney transplant recipients without adequate humoral response following two vaccine doses: protocol for a randomised controlled trial (BECAME study)

IntroductionInadequate antibody response to mRNA SARS-CoV-2 vaccination has been described among kidney transplant recipients. Immunosuppression level and specifically, use of antimetabolite in the maintenance immunosuppressive regimen, are associated with inadequate response. In light of the severe consequences of COVID-19 in solid organ transplant recipients, we believe it is justified to examine new vaccination strategies in these patients.Methods and analysisBECAME is a single-centre, open-label, investigator-initiated randomised controlled, superiority trial, aiming to compare immunosuppression reduction combined with a third BNT162b2 vaccine dose versus third dose alone. The primary outcome will be seropositivity rate against SARS-CoV-2. A sample size of 154 patients was calculated for the seropositivity endpoint assuming 25% seropositivity in the control group and 50% in the intervention group. A sample of participants per arm will be also tested for T-cell response. We also plan to perform a prospective observational study, evaluating seropositivity among ~350 kidney transplant recipients consenting to receive a third vaccine dose, who are not eligible for the randomised controlled trial.Ethics and disseminationThe trial is approved by local ethics committee of Rabin Medical Center (RMC-0192-21). All participants will be required to provide written informed consent. Results of this trial will be published;trial data will be available. Protocol amendments will be submitted to the local ethics committee.Trail registration numberNCT04961229.

Immune Response to Third Dose BNT162b2 COVID-19 Vaccine Among Kidney Transplant Recipients-A Prospective Study.

Immune response to two SARS-CoV-2 mRNA vaccine doses among kidney transplant recipients (KTRs) is limited. We aimed to evaluate humoral and cellular response to a third BNT162b2 dose. In this prospective study, 190 KTRs were evaluated before and ∼3 weeks after the third vaccine dose. The primary outcomes were anti-spike antibody level >4160 AU/ml (neutralization-associated cutoff) and any seropositivity. Univariate and multivariate analyses were conducted to identify variables associated with antibody response. T-cell response was evaluated in a subset of participants. Results were compared to a control group of 56 healthcare workers. Among KTRs, we found a seropositivity rate of 70% (133/190) after the third dose (37%, 70/190, after the second vaccine dose); and 27% (52/190) achieved levels above 4160 AU/ml after the third dose, compared to 93% of controls. Variables associated with antibody response included higher antibody levels after the second dose (odds ratio [OR] 30.8 per log AU/ml, 95% confidence interval [CI]11-86.4, p < 0.001); and discontinuation of antimetabolite prior to vaccination (OR 9.1,95% CI 1.8-46.5, p = 0.008). T-cell response was demonstrated in 13% (7/53). In conclusion, third dose BNT162b2 improved immune response among KTRs, however 30% still remained seronegative. Pre-vaccination temporary immunosuppression reduction improved antibody response.

SARS-CoV-2 antibody dynamics among kidney transplant recipients 3 months after BNT162b2 vaccination: a prospective cohort study.

Data regarding immunogenicity of mRNA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines among kidney transplant recipients in the months following vaccination are lacking. We aimed to investigate humoral immune response at 3-4 months post-vaccination among a cohort of kidney transplant recipients, compared with a control group of dialysis patients. Anti-spike antibodies were tested at 1 and 3-4 months after vaccination. Of 259 kidney transplant recipients tested at a median time of 110 days from second vaccine dose, 99 (38%) were seropositive, compared with 83% (101/122) of control patients. Younger age, better renal function and lower immunosuppression levels were associated with seropositivity. A total of 14% (13/94) of participants seropositive at 1 month became seronegative at follow-up and 11% (18/165) became seropositive. The latter were mainly individuals with higher antibody levels at 1 month. Antibody levels at 3-4 months were significantly reduced in both study groups, although the decline was more pronounced in the control group. Kidney transplant recipients present poor antibody response to mRNA SARS-CoV-2 vaccination, with only 38% seropositive at 3-4 months. Nevertheless, the decay in antibody response over time is modest, and some patients may present delayed response, reaching adequate antibody levels at 3-4 months. Low seropositivity rates in this group call for investigating other immunization strategies.

Humoral serological response to the BNT162b2 vaccine is abrogated in lymphoma patients within the first 12 months following treatment with anti-CD2O antibodies.

Patients with lymphoma, especially those treated with anti-CD20 monoclonal antibodies, suffer high COVID-19-associated morbidity and mortality. The goal of this study was to assess the ability of lymphoma patients to generate a sufficient humoral response after two injections of BNT162b2 Pfizer vaccine and to identify factors influencing the response. Antibody titers were measured with the SARS-CoV-2 IgG II Quant (Abbott ) assay in blood samples drawn from lymphoma patients 4 2 weeks after the second dose of vaccine. The cutoff for a positive response was set at 50 AU/mL. Positive serological responses were observed in 51% of the 162 patients enrolled in this cross-sectional study. In a multivariate analysis, an interval of <12 months between the last anti-CD20 monoclonal antibody dose and the second vaccine dose (odds ratio=31.3 [95% confidence interval: 8.4-116.9], P<0.001) and presence of active lymphoma (odds ratio=4.2 (95% confidence interval: 2.1- 8.2), P=0.006) were identified as negative response predictors. The rate of seropositivity increased from 3% in patients vaccinated within 45 days after the last monoclonal antibody administration to 80% in patients vaccinated >1 year after this therapy. The latter percentage was equal to that of patients never exposed to monoclonal antibodies. In conclusion, lymphoma patients, especially those recently treated with anti- CD20 monoclonal antibodies, fail to develop sufficient humoral response to BNT162b2 vaccine. While a serological response is not the only predictor of immunity, its low level could make this population more vulnerable to COVID-19, which implies the need for a different vaccination schedule for such patients.

Humoral serological response to the BNT162b2 vaccine after allogeneic haematopoietic cell transplantation.

OBJECTIVES: To assess the humoral immune response to the BNT162b2 vaccine after allogeneic haematopoietic cell transplantation (HCT). METHODS: This is a prospective cohort study. The SARS-CoV-2 IgGII Quant (Abbott©) assay was performed 4-6 weeks after the second BNT162b2 vaccine for quantitative measurement of anti-spike antibodies. RESULTS: The cohort included 106 adult patients. Median time from HCT to vaccination was 42 (range 4-439) months. Overall, 15/106 (14%, 95% confidence interval (CI) 7-21%) were seronegative despite vaccination, 14/52 patients on immunosuppression (27%, 95%CI 19-35%) compared to only 1/54 patients off immunosuppression (1.8%, 95%CI 1-4%) (p 0.0002). The proportion of seronegative patients declined with time; it was 46% (6/13) during the first year, 12.5% (3/24) during the second year and 9% (6/69) beyond 2 years from transplant. Patients with acute graft-versus-host disease (GVHD) (odds ratio (OR) 3.3, 95%CI 0.97-11.1, p 0.06) and moderate to severe chronic GVHD (OR 5.9, 95%CI 1.2-29, p 0.03) were more likely to remain seronegative. Vaccination was well tolerated by most patients. However, 7% (7/106) reported that GVHD-related symptoms worsened within days following vaccination. CONCLUSION: A significant proportion of allogeneic HCT recipients receiving immunosuppression demonstrated an inadequate humoral response to the BNT162b2 vaccine. These patients should be recognized and instructed to take appropriate precautions. Recipients who were off immunosuppression had a humoral response that was comparable to that of the general population.

Six-months immunogenicity of BNT162b2 mRNA vaccine in heart transplanted and ventricle assist device-supported patients.

AIMS: To assess the 6 months immunogenicity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine in a population of heart transplanted (HTx) recipients and left ventricular assist device (LVAD)-supported patients. METHODS AND RESULTS: A prospective single-centre cohort study of HTx recipients and LVAD-supported patients who received a two-dose SARSCoV-2 mRNA vaccine (BNT162b2, Pfizer-BioNTech). Whole blood for anti-spike IgG (S-IgG) antibodies were drawn at 6 months after the first vaccine dose. S-IgG data at 6 weeks were available for a subgroup of HTx recipients. S-IgG ≥ 50 AU/mL were interpreted positive. The cohort included 53 HTx recipients and 18 LVAD-supported patients. The median time from HTx or LVAD implantation to the 1st vaccine dose was 90 (IQR 30, 172) months and 22 (IQR 6, 78) months, respectively. The seropositivity rates of S-IgG antibodies and their titre levels in HTx recipients and LVAD-supported patients were 45% and 83% respectively, (P = 0.006), and 35 (IQR 7, 306) AU/mL and 311 (IQR 86, 774) AU/mL, respectively, (P = 0.006). Reduced SARSCoV-2 vaccine immunogenicity in HTx recipients was associated with older age [odds ratio (OR) 0.917 confidence interval (CI 0.871, 0.966), P = 0.011] and with the use of anti-metabolites-based immunosuppressive regimens [OR 0.224 (CI 0.065, 0.777), P = 0.018]. mTOR inhibitors were associated with higher immunogenicity [OR 3.1 (CI 1.01, 9.65), P = 0.048]. Out of 13 HTx recipients who were S-IgG seropositive at 6 weeks after the first vaccine dose, 85% remained S-IgG seropositive at 6 month follow-up. CONCLUSIONS: At 6 months post-vaccination, S-IgG immunogenicity in HTx recipients is low, particularly in older HTx recipients and in those treated with anti-metabolites drugs.

Lower Serologic Response to COVID-19 mRNA Vaccine in Patients With Inflammatory Bowel Diseases Treated With Anti-TNFα.

BACKGROUND & AIM: Patients with inflammatory bowel diseases (IBD), specifically those treated with anti-tumor necrosis factor (TNF)α biologics, are at high risk for vaccine-preventable infections. Their ability to mount adequate vaccine responses is unclear. The aim of the study was to assess serologic responses to messenger RNA-Coronavirus Disease 2019 vaccine, and safety profile, in patients with IBD stratified according to therapy, compared with healthy controls (HCs). METHODS: Prospective, controlled, multicenter Israeli study. Subjects enrolled received 2 BNT162b2 (Pfizer/BioNTech) doses. Anti-spike antibody levels and functional activity, anti-TNFα levels and adverse events (AEs) were detected longitudinally. RESULTS: Overall, 258 subjects: 185 IBD (67 treated with anti-TNFα, 118 non-anti-TNFα), and 73 HCs. After the first vaccine dose, all HCs were seropositive, whereas ∼7% of patients with IBD, regardless of treatment, remained seronegative. After the second dose, all subjects were seropositive, however anti-spike levels were significantly lower in anti-TNFα treated compared with non-anti-TNFα treated patients, and HCs (both P < .001). Neutralizing and inhibitory functions were both lower in anti-TNFα treated compared with non-anti-TNFα treated patients, and HCs (P < .03; P < .0001, respectively). Anti-TNFα drug levels and vaccine responses did not affect anti-spike levels. Infection rate (∼2%) and AEs were comparable in all groups. IBD activity was unaffected by BNT162b2. CONCLUSIONS: In this prospective study in patients with IBD stratified according to treatment, all patients mounted serologic response to 2 doses of BNT162b2; however, its magnitude was significantly lower in patients treated with anti-TNFα, regardless of administration timing and drug levels. Vaccine was safe. As vaccine serologic response longevity in this group may be limited, vaccine booster dose should be considered.

Secondary bacterial infection in COVID-19 patients is a stronger predictor for death compared to influenza patients.

Secondary bacterial infections are a potentially fatal complication of influenza infection. We aimed to define the impact of secondary bacterial infections on the clinical course and mortality in coronavirus disease 2019 (COVID-19) patients by comparison with influenza patients. COVID-19 (n = 642) and influenza (n = 742) patients, admitted to a large tertiary center in Israel and for whom blood or sputum culture had been taken were selected for this study. Bacterial culture results, clinical parameters, and death rates were compared. COVID-19 patients had higher rates of bacterial infections than influenza patients (12.6% vs. 8.7%). Notably, the time from admission to bacterial growth was longer in COVID-19 compared to influenza patients (4 (1-8) vs. 1 (1-3) days). Late infections (> 48 h after admission) with gram-positive bacteria were more common in COVID-19 patients (28% vs. 9.5%). Secondary infection was associated with a higher risk of death in both patient groups 2.7-fold (1.22-5.83) for COVID-19, and 3.09-fold (1.11-7.38) for Influenza). The association with death remained significant upon adjustment to age and clinical parameters in COVID-19 but not in influenza infection. Secondary bacterial infection is a notable complication associated with worse outcomes in COVID-19 than influenza patients. Careful surveillance and prompt antibiotic treatment may benefit selected patients.

Evidence for increased breakthrough rates of SARS-CoV-2 variants of concern in BNT162b2-mRNA-vaccinated individuals.

The BNT162b2 mRNA vaccine is highly effective against SARS-CoV-2. However, apprehension exists that variants of concern (VOCs) may evade vaccine protection, due to evidence of reduced neutralization of the VOCs B.1.1.7 and B.1.351 by vaccine sera in laboratory assays. We performed a matched cohort study to examine the distribution of VOCs in infections of BNT162b2 mRNA vaccinees from Clalit Health Services (Israel) using viral genomic sequencing, and hypothesized that if vaccine effectiveness against a VOC is reduced, its proportion among breakthrough cases would be higher than in unvaccinated controls. Analyzing 813 viral genome sequences from nasopharyngeal swabs, we showed that vaccinees who tested positive at least 7 days after the second dose were disproportionally infected with B.1.351, compared with controls. Those who tested positive between 2 weeks after the first dose and 6 days after the second dose were disproportionally infected by B.1.1.7. These findings suggest reduced vaccine effectiveness against both VOCs within particular time windows. Our results emphasize the importance of rigorously tracking viral variants, and of increasing vaccination to prevent the spread of VOCs.

Evaluation of Seropositivity Following BNT162b2 Messenger RNA Vaccination for SARS-CoV-2 in Patients Undergoing Treatment for Cancer.

Importance: Patients with cancer undergoing treatment are at high risk of COVID-19 following SARS-CoV-2 infection; however, their ability to produce an adequate antibody response to messenger RNA SARS-CoV-2 vaccines is unclear. Objective: To evaluate rates of antispike (anti-S) antibody response to a BNT162b2 vaccine in patients with cancer who are undergoing systemic treatment vs healthy controls. Design, Setting, and Participants: This prospective cohort study included 102 adult patients with solid tumors undergoing active intravenous anticancer treatment and 78 controls who received the second dose of the BNT162b2 vaccine at least 12 days before enrollment. The controls were taken from a convenience sample of the patients' family/caregivers who accompanied them to treatment. The study was conducted between February 22, 2021, and March 15, 2021 at Davidoff Cancer Center at Beilinson Hospital (Petah Tikva, Israel). Interventions: Blood samples were drawn from the study participants. Serum samples were analyzed and the titers of the IgG antibodies against SARS-CoV-2 spike receptor-binding domain were determined using a commercially available immunoassay. Seropositivity was defined as 50 or greater AU/mL. Main Outcomes and Measures: The primary outcome was the rate of seropositivity. Secondary outcomes included comparisons of IgG titers and identifying factors that were associated with seropositivity using univariate/multivariable analyses. Results: The analysis included 180 participants, which comprised 102 patients with cancer (median [interquartile range (IQR)] age, 66 [56-72] years; 58 men [57%]) and 78 healthy controls (median [IQR] age, 62 [49-70] years; 25 men [32%]). The most common tumor type was gastrointestinal (29 [28%]). In the patient group, 92 (90%) were seropositive for SARS-CoV 2 antispike IgG antibodies after the second vaccine dose, whereas in the control group, all were seropositive. The median IgG titer in the patients with cancer was significantly lower than that in the controls (1931 [IQR, 509-4386] AU/mL vs 7160 [IQR, 3129-11 241] AU/mL; P < .001). In a multivariable analysis, the only variable that was significantly associated with lower IgG titers was treatment with chemotherapy plus immunotherapy (ß, -3.5; 95% CI, -5.6 to -1.5). Conclusions and Relevance: In this cohort study of patients with cancer who were receiving active systemic therapy, 90% of patients exhibited adequate antibody response to the BNT162b2 vaccine, although their antibody titers were significantly lower than those of healthy controls. Further research into the clinical relevance of lower titers and their durability is required. Nonetheless, the data support vaccinating patients with cancer as a high priority, even during therapy.

Immunogenicity of the BNT162b2 mRNA vaccine in heart transplant recipients - a prospective cohort study.

AIMS: To assess the short-term immunogenicity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine in a population of heart transplant (HTx) recipients. A prospective single-centre cohort study of HTx recipients who received a two-dose SARS-CoV-2 mRNA vaccine (BNT162b2, Pfizer-BioNTech). METHODS AND RESULTS: Whole blood for anti-spike IgG (S-IgG) antibodies was drawn at days 21-26 and at days 35-40 after the first vaccine dose. Geometric mean titres (GMT) ≥50 AU/mL were interpreted positive. Included were 42 HTx recipients at a median age of 61 [interquartile range (IQR) 44-69] years. Median time from HTx to the first vaccine dose was 9.1 (IQR 2.6-14) years. Only 15% of HTx recipients demonstrated the presence of positive S-IgG antibody titres in response to the first vaccine dose [GMT 90 (IQR 54-229) AU/mL]. Overall, 49% of HTx recipients induced S-IgG antibodies in response to either the first or the full two-dose vaccine schedule [GMT 426 (IQR 106-884) AU/mL]. Older age [68 (IQR 59-70) years vs. 46 (IQR 34-63) years, P = 0.034] and anti-metabolite-based immunosuppression protocols (89% vs. 44%, P = 0.011) were associated with low immunogenicity. Importantly, 36% of HTx recipients who were non-responders to the first vaccine dose became S-IgG seropositive in response to the second vaccine dose. Approximately a half of HTx recipients did not generate S-IgG antibodies following SARS-CoV-2 two-dose vaccine. CONCLUSIONS: The generally achieved protection from SARS-CoV-2 mRNA vaccination should be regarded with caution in the population of HTx recipients. The possible benefit of additive vaccine should be further studied.

Antibody response to SARS-CoV-2 mRNA vaccine among kidney transplant recipients: a prospective cohort study.

OBJECTIVES: We aimed to evaluate the rates of antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine among kidney transplant recipients, and to identify factors associated with reduced immunogenicity. METHODS: This was a prospective cohort study including consecutive kidney transplant recipients in a single referral transplant centre. Participants were tested for anti-spike (anti-S) antibodies 2-4 weeks after a second vaccine dose. Primary outcome was rate of seropositivity. Univariate and multivariate analyses were conducted to identify factors associated with seropositivity. RESULTS: Of 308 kidney transplant recipients included, only 112 (36.4%) tested positive for anti-S antibodies 2-4 weeks after receiving the second dose of BNT162b2 vaccine. Median antibody titre was 15.5 AU/mL (interquartile range (IQR) 3.5-163.6). Factors associated with antibody response were higher estimated glomerular filtration rate (eGFR) (odds ratio (OR) 1.025 per mL/min/1.73 m2, 95% confidence interval (CI) 1.014-1.037, p < 0.001), lower mycophenolic acid dose (OR 2.347 per 360 mg decrease, 95%CI 1.782-3.089, p < 0.001), younger age (OR 1.032 per year decrease, 95%CI 1.015-1.05, p < 0.001) and lower calcineurin inhibitor (CNI) blood level (OR 1.987, 95%CI 1.146-3.443, p 0.014). No serious adverse events resulting from the vaccine were reported. CONCLUSIONS: Kidney transplant recipients demonstrated an inadequate antibody response to SARS-CoV-2 mRNA vaccination. Immunosuppression level was a significant factor in this response. Strategies to improve immunogenicity should be examined in future studies.

A real-life setting evaluation of the effect of remdesivir on viral load in COVID-19 patients admitted to a large tertiary centre in Israel.

OBJECTIVES: The effectiveness of remdesivir, a Food and Drug Administration-approved drug for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has been repeatedly questioned during the current coronavirus disease 2019 (COVID-19) pandemic. Most of the recently reported studies were randomized controlled multicentre clinical trials. Our goal was to test the efficiency of remdesivir in reducing nasopharyngeal viral load and hospitalization length in a real-life setting in patients admitted to a large tertiary centre in Israel. METHODS: A total of 142 COVID-19 patients found to have at least three reported SARS-CoV-2 quantitative RT-PCR tests during hospitalization were selected for this study. Of these, 29 patients received remdesivir, while the remaining non-treated 113 patients served as controls. RESULTS: Among the tested parameters, the control and remdesivir groups differed significantly only in the intubation rates. Remdesivir treatment did not significantly affect nasopharyngeal viral load, as determined by comparing the differences between the first and last cycle threshold values of the SARS-CoV-2 quantitative RT-PCR tests performed during hospitalization (cycle threshold 7.07 ± 6.85 vs. 7.08 ± 7.27, p 0.977 in the control and treated groups, respectively). Remdesivir treatment shortened hospitalization length by less than a day compared with non-treated controls and by 3.1 days when non-intubated patients from both groups were compared. These differences, however, were not statistically significant, possibly because of the small size of the remdesivir group. DISCUSSION: Remdesivir was not associated with nasopharyngeal viral load changes, but our study had a significant disease severity baseline imbalance and was not powered to detect viral load or clinical differences.