Long follow-up of BNT162b2 mRNA vaccine in healthcare workers (2020-2022): A retrospective longitudinal SARS-CoV-2 serological surveillance.

SARS-CoV-2 anti-spike IgG production and protection from severe respiratory illness should be explored in greater depth after COVID-19 booster vaccination. This longitudinal observational retrospective study investigated the anti-spike IgG response elicited by the first, second and booster doses of BNT162b2 mRNA vaccine in healthcare workers (HCW) at San Martino IRCCS Policlinico Hospital (Genoa) up to the 12th month. Sequential blood sampling was performed at T0 (prior to vaccination), T1 (21 days after the 1st dose of vaccine), T2, T3, T4, T5, T6 (7 days and 1, 3, 6 and 9 months after the 2nd dose, respectively), T7 and T8 (1 and 3 months after a booster dose). A SARS-CoV-2 IgG panel (Bio-Rad, Marnes-la-Coquette, France) was used to determine levels of receptor-binding domain (RBD), spike-1 (S1), spike-2 and nucleocapsid structural proteins of SARS-CoV-2. In the 51 HCWs evaluated, seroprevalence was 96% (49/51) at T1 and 100% (51/51) from T2 to T5 for RBD and S1. At T6, only one HCW was negative. T2 [RBD = 2945 (IQR:1693-5364); S1 = 1574 (IQR:833-3256) U/mL], and T7 [RBD = 8204 (IQR:4129-11,912); S1 = 4124 (IQR:2124-6326) U/mL] were characterized by the highest antibody values. Significant humoral increases in RBD and S1 were documented at T7 and T8 compared to T2 and T4, respectively (p-value < .001). Following vaccination with BNT162b2 and a booster dose in the 9th month, naïve and healthy subjects show high antibody titers up to 12 months and a protective humoral response against COVID-19 disease lasting up to 20 months after the last booster.

Rapid diagnosis of SARS-CoV-2 pneumonia on lower respiratory tract specimens.

BACKGROUND: The ongoing SARS-CoV-2 pandemic requires the availability of accurate and rapid diagnostic tests, especially in such clinical settings as emergency and intensive care units. The objective of this study was to evaluate the diagnostic performance of the Vivalytic SARS-CoV-2 rapid PCR kit in lower respiratory tract (LRT) specimens. METHODS: Consecutive LRT specimens (bronchoalveolar lavage and bronchoaspirates) were collected from Intensive Care Units of San Martino Hospital (Genoa, Italy) between November 2020 and January 2021. All samples underwent RT-PCR testing by means of the Allplex™ SARS-CoV-2 assay (Seegene Inc., South Korea). On the basis of RT-PCR results, specimens were categorized as negative, positive with high viral load [cycle threshold (Ct) ≤ 30] and positive with low viral load (Ct of 31-35). A 1:1:1 ratio was used to achieve a sample size of 75. All specimens were subsequently tested by means of the Vivalytic SARS-CoV-2 rapid PCR assay (Bosch Healthcare Solutions GmbH, Germany). The diagnostic performance of this assay was assessed against RT-PCR through the calculation of accuracy, Cohen's κ, sensitivity, specificity and expected positive (PPV) and negative (NPV) predictive values. RESULTS: The overall diagnostic accuracy of the Vivalytic SARS-CoV-2 was 97.3% (95% CI: 90.9-99.3%), with an excellent Cohen's κ of 0.94 (95% CI: 0.72-1). Sensitivity and specificity were 96% (95% CI: 86.5-98.9%) and 100% (95% CI: 86.7-100%), respectively. In samples with high viral loads, sensitivity was 100% (Table 1). The distributions of E gene Ct values were similar (Wilcoxon's test: p = 0.070), with medians of 35 (IQR: 25-36) and 35 (IQR: 25-35) on Vivalytic and RT-PCR, respectively (Fig. 1). NPV and PPV was 92.6% and 100%, respectively. Table 1 Demographic characteristics and data sample type of the study cases (N = 75) Male, N (%) 56 (74.6%) Age (yr), Median (IQR) 65 (31-81) BAS, N (%) 43 (57.3%)  Negative 30.2%  Positive-High viral load [Ct ≤ 30] 27.9%  Positive-Low viral load [Ct 31-35] 41.9% BAL, N (%) 32 (42.7%)  Negative 37.5%  Positive-High viral load [Ct ≤ 30] 40.6%  Positive-Low viral load [Ct 31-35] 21.9% Data were expressed as proportions for categorical variables. Specimens were categorized into negative, positive with high viral load [cycle threshold (Ct) ≤ 30] and positive with low viral load (Ct of 31-35). BAS bronchoaspirates, BAL bronchoalveolar lavage, Ct cycle threshold Fig. 1 Distribution of E gene cycle threshold values of the rapid PCR and RT-PCR CONCLUSIONS: Vivalytic SARS-CoV-2 can be used effectively on LRT specimens following sample liquefaction. It is a feasible and highly accurate molecular procedure, especially in samples with high viral loads. This assay yields results in about 40 min, and may therefore accelerate clinical decision-making in urgent/emergency situations.

CMV infection after transplant from cord blood compared to other alternative donors: the importance of donor-negative CMV serostatus.

Cytomegalovirus (CMV) infection and disease are important complications after hematopoietic stem cell transplant, particularly after transplant from alternative donors. Allogeneic cord blood transplantation (CBT) is being increasingly used, but immune recovery may be delayed. The aim of this study was to compare CMV infection in CBT with transplants from unrelated or mismatched related donors, from now on defined as alternative donors. A total of 165 consecutive transplants were divided in 2 groups: (1) alternative donors transplants (n = 85) and (2) CBT recipients (n = 80). Donor and recipient (D/R) CMV serostatus were recorded. The incidence of CMV infection, its severity, timing, and outcome were compared. Median follow-up was 257 days (1-1328). CMV infection was monitored by CMV antigenemia and expressed as CMV Ag positive cell/2 × 10(5) polymorphonuclear blood cells. There was a trend toward a higher cumulative incidence of CMV infection among CBT than alternative donor transplant recipients (64% vs 51%, P = .12). The median time to CMV reactivation was 35 days, and was comparable in the 2 groups (P = .8). The maximum number of CMV-positive cells was similar in the 2 groups (11 versus 16, P = .2). The time interval between the first and the last positive CMV antigenemia was almost 4 times longer in CBT compared with alternative donor transplants (109 vs 29 days, respectively, P = .008). The incidence of late CMV infection was also higher in CBT (62% vs 24%, P < .001). The incidence of early and late CMV infection in CBT was similar to D-/R+ alternative transplants, and higher than in D+/R+ alternative transplants: early infection, 72% in CBT versus 69% in D-/R+ alternative versus 55% in D+/R+ alternative (P = .21); and late infection, 67% in CBT versus 60% in D-/R+ alternative versus 7% in D+/R+ alternative (P < .001). Transplant-related mortality and overall survival were similar between the groups: 34% versus 36% (P = .6) and 54% versus 46% (P = .3) for alternative transplant and CBT, respectively. Longer duration and higher incidence of late CMV infection was seen in CBT patients, when compared with alternative donor transplants, whereas no difference in mortality was observed. The duration and incidence of late CMV infection were similar when D-/R+ CBT were compared with D-/R+ alternative donor transplants.

Rituximab treatment for Epstein-Barr virus DNAemia after alternative-donor hematopoietic stem cell transplantation.

We report 55 patients undergoing an alternative-donor hematopoietic stem cell transplantation (HSCT) who developed Epstein-Barr virus (EBV) DNAemia, with >1000 EBV copies/10(5) peripheral blood mononuclear cells (PBMCs), and were treated with rituximab (375 mg/m(2)). The median patient age was 47 years (range, 20-65 years), and graft sources were mismatched family members (n = 4), unrelated donors (n = 46), and unrelated cord blood (n = 5). The conditioning regimen included antithymocyte globulin (ATG) in all patients. The median time to development of EBV DNAemia was day 27 post-HSCT (range, day 5 to day 242), with a median of 60 EBV copies/10(5) PBMCs (range, 1-5770 copies/10(5) PBMCs). The number of EBV copies was reduced to <1000/10(5) PBMCs on day +7 after initiation of rituximab therapy in 51% of the patients, on day +14 in 73% of the patients, and on +21 in 92% of the patients. Overall, 50 of 55 patients (91%) cleared EBV after one dose (n = 25) or more than one dose (n = 25) of rituximab. Factors predicting transplantation-related mortality (TRM) in multivariate analysis were a reduction to <1000 EBV copies/10(5) PBMCs by day +7 of treatment (relative risk [RR], 0.2; P = .01) and disease phase in remission (RR, 0.3; P = .05). TRM was 23% in the 40 patients with none or one of the negative predictors and 60% in the 15 patients with both negative predictors (P = .001). Of these latter 15 patients, 3 developed clinical posttransplantation lymphoproliferative disorder (PTLD). All 3 of these patients had a high EBV load on day +7 of rituximab therapy. This study confirms the effectiveness of rituximab in controlling EBV DNAemia in patients undergoing allogeneic HSCT. Patients with increasing EBV copies despite rituximab therapy are at high risk for EBV PTLD and may be considered for alternative therapies.