Comparison of Elecsys and Liaison immunoassays to determine Epstein-Barr virus serological status using further diagnostic approaches to clarify discrepant results.

Serological markers for Epstein-Barr virus (EBV) infection are commonly used to diagnose infectious mononucleosis and establish a serological status in pretransplant patients. This study prospectively assessed 1043 serum specimens sent to the laboratory for physician-ordered EBV testing. The three markers-antiviral capsid antigen (VCA) immunoglobulin M (IgM), anti-VCA immunoglobulin G (IgG), and anti-Epstein-Barr nuclear antigen (EBNA) antibodies-were tested using the Elecsys and the Liaison immunoassays. Specimens with discrepant results between the two assays were assessed using further EBV diagnostic approaches to conclude on the EBV serological status. In spite of substantial agreement between the two assays (88%) and with the presumed EBV status (>92%), the results showed differences in the performance of the assays. Liaison VCA IgM appeared to be the most sensitive test for the detection of the 38 sera classified as early primary infection in comparison with the Elecsys assay (91.4% vs. 68.6%, p = 0.008). Excluding the cases of early primary infection, the sensitivity values of the VCA IgM marker were comparable between the Liaison and Elecsys assays (95.2% and 92.9%, respectively, p = 1). Concerning the sera classified as past infection (n = 763), the Elecsys assay showed higher sensitivity values for the detection of the VCA and EBNA IgG markers in comparison with the Liaison assay (99.9% and 99.7% vs. 97.4% and 91.2%, respectively, p < 0.001). Overall, the Elecsys and Liaison assays showed similar performance. The interpretation of EBV serological profiles based on the clinical context may require serology follow up or further diagnostic approaches in challenging cases.

SARS-CoV-2 Variants in Immunocompromised Patient Given Antibody Monotherapy.

A 72-year-old immunocompromised man infected with severe acute respiratory syndrome coronavirus 2 received bamlanivimab monotherapy. Viral evolution was monitored in nasopharyngeal and blood samples by melting curve analysis of single-nucleotide polymorphisms and whole-genome sequencing. Rapid emergence of spike receptor binding domain mutations was found, associated with a compartmentalization of viral populations.

Risk factors of BK viral hemorrhagic cystitis in allogenic hematopoietic stem cell transplantation.

Reactivation of BK virus (BKV) can occur during intensive immunosuppression such as in allogenic hematopoietic stem cell transplant (AHSCT) recipients for whom a systematic PCR urine test for BKV will be positive in 50% to 100% of patients. Only 5% to 40% will develop BKV hemorrhagic cystitis (HC). Thus, BKV PCR testing is useful to confirm a diagnosis of BKV-HC but not to predict its occurrence. The aim of this retrospective study was to ascertain the risk factors of developing BKV HC, mostly in patients receiving posttransplant cyclophosphamide. The study looked at data from Grenoble Alpes University Hospital included in the national retrospective register ProMISe, administered by the "Société Francophone de Greffe de Moelle et de Thérapie Cellulaire". Urine BKV PCR was performed when patients presented grade ≥ 2 hematuria with clinical symptoms of cystitis. BKV-HC was defined as an association of clinical symptoms of cystitis, grade ≥ 2 hematuria and BKV viruria > 7 log10 copies/ml. From January 2014 to January 2018, 168 AHSCTs were considered for analysis, of which 43 (25.6%) developed BKV-HC and 44.9% of the subgroup that received posttransplant cyclophosphamide. After logistic regression, the risk factors associated with BKV-HC were reduced to posttransplantation exposure to cyclophosphamide (OR 4.25, [1.66; 10.87], P = .02), age < 40 y (OR 3.85 [1.51; 9.80], P = .005) and corticosteroid therapy (OR 3.86, [1.59; 9.36], P = .003). Exposure to cyclophosphamide, younger age (<40) and corticosteroid therapy are potential risk factors for BKV-HC.

Exogenous human herpesvirus 6 reinfection after tumor-infiltrating T-lymphocyte therapy.

Exogenous human herpes virus 6 (HHV-6) reinfection has never been reported in patients receiving tumor-infiltrating T lymphocytes therapy. We report an unusual case of HHV-6 infection following infusion of HHV-6 infected autologous T lymphocytes. HHV-6 infection could interfere with the tumor antigen immune recognition and the efficacy of immunotherapy.

Multicenter Evaluation of Whole-Blood Epstein-Barr Viral Load Standardization Using the WHO International Standard.

The first WHO international standard for Epstein-Barr virus (EBV) (WHO EBV standard) for nucleic acid amplification technology (NAT)-based assays was commercialized in January 2012 by the National Institute for Biological Standards and Control. In the study reported here, we compared whole-blood EBV DNA load (EDL) results from 12 French laboratories for seven samples (Quality Controls for Molecular Diagnostics 2013 proficiency panel) in order to determine whether expression in international units reduces interlaboratory variability in whole-blood EDLs. Each testing laboratory used a conversion factor to convert EDL results from copies per milliliter to international units per milliliter. This conversion factor was calculated from the WHO EBV standard according to the protocol described in this study (nine laboratories) or the recommendations of the PCR kit suppliers (three laboratories). The interlaboratory variability in whole-blood EDL results was reduced after standardization of the results using the WHO EBV standard. For the seven samples tested, standard deviations (SD) ranged from 0.41 to 0.55 when the results were expressed in log copies per milliliter, whereas the SD ranged from 0.17 to 0.32 when results were given in log international units per milliliter. Comparing the variance data (F test), we showed that the dispersion of whole-blood EDL results was significantly lower when they were expressed in log international units per milliliter (P < 0.001 for six of seven samples and P < 0.05 for one sample with a low mean EDL of 2.62 log IU/ml). This study showed that the use of the WHO EBV standard could improve the homogeneity of whole-blood EDL results between laboratories as well as the monitoring of patients at high risk of posttransplant lymphoproliferative disorders or other EBV-associated diseases.

Methylation of Epstein-Barr virus Rta promoter in EBV primary infection, reactivation and lymphoproliferation.

During Epstein-Barr virus (EBV) latency, the EBV genome is largely silenced by methylation. This silencing is overturned during the switch to the lytic cycle. A key event is the production of the viral protein Zta which binds to three Zta-response elements (ZRE) from the Rta promoter (Rp), two of which (ZRE2 and ZRE3) include three CpG motifs methylated in the latent genome. The bisulphite pyrosequencing reaction was used to quantify the methylation of ZRE2, ZRE3a, and ZRE3b in EBV-positive cell lines and in ex vivo samples of EBV-related diseases, in order to assess whether the level of methylation in these ZREs could provide additional information to viral DNA load and serology in the characterization of EBV-associated diseases. In PBMC from two patients with infectious mononucleosis, over time Rp became increasingly methylated whereas EBV load decreased. In tonsil from patients with chronic tonsillitis, the methylation was less than in EBV-associated tumors, regardless of the viral load. This was even more striking when only the ZRE3a and ZRE3b were considered since some samples presented unbalanced profiles on ZRE2. EBV reactivation in cell culture showed that the reduction in the overall level of methylation was closely related to the production of unmethylated virions. Thus, an assessment of the level of methylation may help to better characterize EBV replication in PBMC and in biopsies with high EBV load, during infectious mononucleosis and EBV-associated cancers. J. Med. Virol. 88:1814-1820, 2016. © 2016 Wiley Periodicals, Inc.

Dynamics of Epstein-Barr viral load after hematopoietic stem cell transplantation and effect of preemptive rituximab therapy.

BACKGROUND: Epstein-Barr virus (EBV) displays oncogenic properties, particularly in the immunocompromised host. Notably, hematopoietic stem cell transplantation (HSCT) recipients with a detectable blood EBV viral load (BEBVL) are considered at higher risk of post-transplant lymphoproliferative diseases (PTLD). Therefore, BEBVL is monitored after HSCT, and preemptive rituximab may be used in patients with high values. However, little is known about post-HSCT BEBVL dynamics, and the threshold that should lead to anti-CD20 therapy is poorly defined. METHODS: We retrospectively analyzed the post-HSCT BEBVL of 332 adult HSCT recipients in our center from 2005 to 2013, including the effect of rituximab. RESULTS: Detection of BEBVL >100, 1000, 5000, 10 000, and 50 000 copies/mL occurred in, respectively, 77.7%, 69.6%, 37.0%, 27.1%, and 7.5% of the patients after a respective median time of 9, 14, 15, 16, and 14 weeks. No BEBVL threshold was associated with an overall survival difference. Seventy-eight patients received rituximab, with a BEBVL decrease in most. Among patients with detectable BEBVL, long-term survival did not differ in rituximab treated and non-treated, except for patients with BEBVL ≥50 000. Only one case of PTLD was observed. CONCLUSIONS: BEBVL is frequently detectable after HSCT, but suggests no strong association with survival. Preemptive rituximab therapy threshold remains to be defined.

Evaluation of Torque Teno Virus DNA Load as a Predictive Biomarker in Kidney Transplant Recipients Converted from Calcineurin Inhibitors to Belatacept.

Introduction: Belatacept is a relevant alternative to calcineurin inhibitors (CNIs) after kidney transplantation (KT). Circulating Torque Teno virus (TTV) DNA load is correlated to infections and rejection risks post-KT in patients treated with CNIs. The aim of this study was to assess the TTV DNA load profile in kidney transplant recipients converted from CNIs to belatacept and explore its use as a predictive biomarker. Methods: Sixty-eight single-center kidney transplanted recipients who were converted from CNIs to belatacept between June, 2015 and December, 2020 were included in this study. Whole blood TTV DNA load was measured before, at 3, 6, and 12 months post-belatacept conversion. Our primary end point was to assess the TTV DNA load profile and correlate the results with rejection and opportunistic infection (OPI). Results: TTV DNA load remained stable after belatacept conversion, that is, 3.8 (3.1-4.9), 4.4 (3.2-5.4), 4.0 (3.0-5.7) and 4.2 (3.0-5.2) log10 copies/ml at baseline, 3, 6, and 12 months, respectively. No correlation was found between TTV DNA load and post-KT complications. Chronic allograft dysfunction at 1 year postconversion was associated with a lower TTV DNA load after 6 and 12-months (P = 0.014 and P = 0.021, respectively). A higher TTV DNA load was found in older patients and in those with higher body mass index (BMI) (P = 0.023 and P = 0.005, respectively). Conclusion: Conversion from CNIs to belatacept did not affect TTV DNA load. OPIs or acute rejection occurrences were not associated with TTV DNA load. However, low TTV (lTTV) DNA load after 6 months postconversion may be a promising tool to predict graft dysfunction risk at 1-year postconversion.

Cytomegalovirus detection is associated with ICU admission in non-AIDS and AIDS patients with Pneumocystis jirovecii pneumonia.

OBJECTIVES: Cytomegalovirus (CMV) is frequently detected in lung and/or blood samples of patients with Pneumocystis jirovecii pneumonia (PJP), although this co-detection is not precisely understood. We aimed to determine whether PJP was more severe in case of CMV detection. METHODS: We retrospectively included all patients with a diagnosis of PJP between 2009 and 2020 in our centre and with a measure of CMV viral load in blood and/or bronchoalveolar lavage (BAL). PJP severity was assessed by the requirement for intensive care unit (ICU) admission. RESULTS: The median age of the 249 patients was 63 [IQR: 53-73] years. The main conditions were haematological malignancies (44.2%), solid organ transplantations (16.5%), and solid organ cancers (8.8%). Overall, 36.5% patients were admitted to ICU. CMV was detected in BAL in 57/227 patients; the 37 patients with viral load ≥3 log copies/mL were more frequently admitted to ICU (78.4% vs 28.4%, p<0.001). CMV was also detected in blood in 57/194 patients; the 48 patients with viral load ≥3 log copies/mL were more frequently admitted to ICU (68.7% vs 29.4%, p<0.001). ICU admission rate was found to increase with each log of BAL CMV viral load and each log of blood CMV viral load. CONCLUSIONS: PJP is more severe in the case of concomitant CMV detection. This may reflect either the deleterious role of CMV itself, which may require antiviral therapy, or the fact that patients with CMV reactivation are even more immunocompromised.

Virological Markers in Epstein-Barr Virus-Associated Diseases.

Epstein-Barr virus (EBV) is an oncogenic virus infecting more than 95% of the world's population. After primary infection-responsible for infectious mononucleosis in young adults-the virus persists lifelong in the infected host, especially in memory B cells. Viral persistence is usually without clinical consequences, although it can lead to EBV-associated cancers such as lymphoma or carcinoma. Recent reports also suggest a link between EBV infection and multiple sclerosis. In the absence of vaccines, research efforts have focused on virological markers applicable in clinical practice for the management of patients with EBV-associated diseases. Nasopharyngeal carcinoma is an EBV-associated malignancy for which serological and molecular markers are widely used in clinical practice. Measuring blood EBV DNA load is additionally, useful for preventing lymphoproliferative disorders in transplant patients, with this marker also being explored in various other EBV-associated lymphomas. New technologies based on next-generation sequencing offer the opportunity to explore other biomarkers such as the EBV DNA methylome, strain diversity, or viral miRNA. Here, we review the clinical utility of different virological markers in EBV-associated diseases. Indeed, evaluating existing or new markers in EBV-associated malignancies or immune-mediated inflammatory diseases triggered by EBV infection continues to be a challenge.

Epstein-Barr Virus Encephalitis: A Review of Case Reports from the Last 25 Years.

Although uncommon, Epstein-Barr virus-related neurological disorders represent the seventh most frequent cause of infectious encephalitis in adults. The limited number of publications on EBV encephalitis mainly document isolated clinical cases. This study aimed to summarize published data on EBV encephalitis. A systematic literature search identified 97 EBV encephalitis cases. In the selected cases, EBV-related neurological disorders manifested as lymphocytic pleocytosis in the cerebrospinal fluid (CSF) with moderate hyperproteinorachia. The EBV PCR test was positive in 87% of the CSF samples, with wide-ranging viral loads. When encephalitis occurred in the context of past EBV infections, all of the EBV PCR tests on CSF samples were positive. On the contrary, negative EBV PCR tests on CSF samples occurred only in the context of primary infections. EBV PCR was rarely carried out on blood samples, contributing minimally to the diagnosis. For the treatment of EBV encephalitis, Aciclovir was used alone in 29% of cases, and in association with other drugs in 40% of cases. Ganciclovir (30%), corticoids (52%), and immunoglobulins (15%) were mainly used in association with other drugs. Cerebral imaging was abnormal in 69% of cases, mostly in the cerebellum and basal ganglia. This work highlights that the EBV PCR test on CSF samples is currently the main laboratory diagnostic test to diagnose EBV encephalitis. This diagnostic test is useful; however, it is imperfect. New complementary diagnostic tools, approved treatments, and standardized practices could improve patient management.

Fatal HSV-2 primary infection most likely acquired by kidney transplantation: A case report.

Herpes simplex virus 2 (HSV-2) rarely causes severe disease, even in solid organ transplant recipients. This paper describes a fatal case of HSV-2 infection, probably transmitted from a donor to a kidney transplant recipient. The donor was seropositive for HSV-2 but not for HSV-1, whereas the recipient was seronegative for both viruses before transplantation, suggesting that the graft was the source of infection. The recipient received valganciclovir prophylaxis due to cytomegalovirus seropositivity. Three months after transplantation, the recipient presented with rapidly disseminated cutaneous HSV-2 infection with meningoencephalitis. The HSV-2 strain was resistant to acyclovir, probably acquired under valganciclovir prophylaxis. Despite early initiation of acyclovir therapy, the patient died. This fatal case of HSV-2 infection, probably transmitted by the kidney graft with acyclovir-resistant HSV-2 from the onset, is uncommon.

Torque teno virus viremia and QuantiFERON®-CMV assay in prediction of cytomegalovirus reactivation in R+ kidney transplant recipients.

Introduction: Cytomegalovirus (CMV) is the most frequent infectious complication following solid organ transplantation. Torque teno viruses (TTV) viremia has been proposed as a biomarker of functional immunity in the management of kidney transplant recipients (KTR). The QuantiFERON®-CMV (QF-CMV) is a commercially available assay that allows the assessment of CD8+ T-cell responses in routine diagnostic laboratories. Methods: In a prospective national multicenter cohort of 64 CMV-seropositive (R+) KTR, we analyzed the value of TTV load and the two markers of the QF-CMV assay [QF-Ag (CMV-specific T-cell responses) and QF-Mg (overall T-cell responses)], alone and in combination, in prediction of CMV reactivation (≥3 log10 IU/ ml) in the first post-transplant year. We compared previously published cut-offs and specific cut-offs optimized from ROC curves for our population. Results: Using the conventional cut-off (3.45 log10 copies/ml), TTV load at D0 [inclusion visit on the day of transplantation before induction (D0)], or at M1 (1-month post-transplant visit) perform better in predicting CMV viremia control than CMV reactivation. Survival analyses suggest a better performance of our optimized TTV cut-offs (3.78 log10 copies/ml at D0 and 4.23 log10 copies/ml at M1) for risk stratification of CMV reactivation in our R+ KTR cohort. The QF-CMV (QF-Ag = 0.2 IU/ml, and QF-Mg = 0.5 IU/ml) also appears to better predict CMV viremia control than CMV reactivation. Moreover, survival analyses suggest that the QF-Mg would perform better than the QF-Ag in stratifying the risk of CMV reactivation. The use of our optimized QF-Mg cut-off (1.27 IU/ml) at M1 further improved risk stratification of CMV reactivation. Using conventional cut-offs, the combination of TTV load and QF-Ag or TTV load and QF-Mg did not improve prediction of CMV viremia control compared to separate analysis of each marker but resulted in an increase of positive predictive values. The use of our cut-offs slightly improved risk prediction of CMV reactivation. Conclusion: The combination of TTV load and QF-Ag or TTV load and QF-Mg could be useful in stratifying the risk of CMV reactivation in R+ KTR during the first post-transplant year and thereby have an impact on the duration of prophylaxis in these patients. Clinical trial registration: ClinicalTrials.gov registry, identifier NCT02064699.

Three-dimensional structure of the Epstein-Barr virus capsid.

Epstein-Barr virus (EBV), a gammaherpesvirus, infects >90 % of the world's population. Primary infection by EBV can lead to infectious mononucleosis, and EBV persistence is associated with several malignancies. Despite its importance for human health, little structural information is available on EBV. Here we report the purification of the EBV capsid by CsCl- or sucrose density-gradient centrifugation. Cryo-electron microscopy and image analysis resulted in two slightly different three-dimensional structures at about 20 Šresolution. These structures were compared with that of human herpesvirus 8, another gammaherpesvirus. CsCl-gradient purification leads to the removal of part of the triplex complex around the fivefold axes, whereas the complexes between hexons remained in place. This may be due to local differences in stability resulting from variation in quasi-equivalent interactions between pentons and hexons compared with those between hexons only.

Comparison of commercial extraction systems and PCR assays for quantification of Epstein-Barr virus DNA load in whole blood.

The automation of DNA extraction and the use of commercial quantitative real-time PCR assays could help obtain more reliable results for the quantification of Epstein-Barr virus DNA loads (EBV VL). This study compared two automated extraction platforms and two commercial PCRs for measurement of EBV VL in 10 EBV specimens from Quality Control for Molecular Diagnostics (QCMD) and in 200 whole-blood (WB) specimens from transplant (n = 137) and nontransplant (n = 63) patients. The WB specimens were extracted using the QIAcube or MagNA Pure instrument; VL were quantified with the EBV R-gene quantification kit (Argene) or the artus EBV RG PCR kit (Qiagen) on the Rotor-Gene 6000 real-time analyzer; and the results were compared with those of a laboratory-developed PCR. DNA was extracted from the QCMD specimens by use of the QIAamp DNA minikit and was quantified by the three PCR assays. The extraction platforms and the PCR assays showed good correlation (R, >0.9; P, <0.0001), but as many as 10% discordant results were observed, mostly for low viral loads (<3 log(10) copies/ml), and standard deviations reached as high as 0.49 log(10) copy/ml. In WB but not in QCMD samples, Argene PCR tended to give higher VL values than artus PCR or the laboratory-developed PCR (mean difference for the 200 WB VL, -0.42 or -0.36, respectively). In conclusion, the two automated extraction platforms and the two PCRs provided reliable and comparable VL results, but differences greater than 0.5 log(10) copy/ml remained between the two commercial PCRs after common DNA extraction.

Letermovir use to treat complex cytomegalovirus reactivations in two heart transplant recipients.

Letermovir, an anti-cytomegalovirus (CMV) drug, is recommended as a prophylactic agent in patients at risk of CMV infection/reactivation after allogeneic hematopoietic stem cell transplant. We report the curative and pre-emptive use of letermovir in two heart transplant recipients. In one patient with ganciclovir-resistant CMV, letermovir was successfully used to treat CMV colitis. In the second patient, letermovir was used as pre-emptive therapy for CMV reactivation, but did not prevent CMV esophagitis. In both cases, letermovir was successful for secondary prophylaxis. Curative use of letermovir may be considered if resistance or major adverse effect of other antivirals therapy is suspected.

Use of RT-PCR thermocycling program for the quantification of DNA viruses in a single run with RNA viruses: Example of Altona RealStar® HSV or VZV PCR kits.

Real-time PCR plays a key role in the diagnosis of viral infections. Multiple kits can detect or quantify genomes of various viruses with the same thermocycling program. Detection of RNA viruses includes an additional step of reverse transcription and challenge their detection in a single run with DNA viruses. We investigated the analytical performance of HSV-1, HSV-2 and VZV DNA quantification with Altona RealStar® PCR kits using the RT-PCR program for RNA viruses instead of the PCR program for DNA viruses. For each three viruses, Bland-Altman distribution did not show differences between both programs, and quantification curves generated with both thermocycling programs confirmed high correlation (R2 ≥ 0.9983). Detection of low viral load samples was evaluated, on 10-times repeat-test. All replicate samples were detected with both thermocycling programs and were quantified at similar viral loads (bias in log10 copies/mL: +0.05 (HSV-1), -0.01 (HSV-2) and +0.25 (VZV)). This confirms the feasibility of using the RT-PCR thermocycling program to detect and quantify the genome of RNA and DNA viruses in a single run.

Conversion to mTOR-Inhibitors Plus IV Immunoglobulins in Kidney-Transplant Recipients with BKV Infection: A Retrospective Comparative Study.

BK virus-associated nephropathy (PvAN) increases the risk of graft failure justifying treatment. Conversion to mammalian target of rapamycin inhibitors (mTORi) and Human polyclonal immunoglobulins (IVIg) could prevent the risk of PvAN. Our retrospective study assessed the efficacy of mTORi associated with IVIg therapy (mTORi±IVIg group) versus standard immunosuppression reduction to clear BKV DNAemia. Among forty-three kidney-transplanted patients with positive BKV DNAemia, we included twenty-six patients in the mTORi±IVIg group and reduced immunosuppression therapy for seventeen patients. We focused on BKV DNAemia clearance on the first-year. Renal function, rejection rate, evolution to PvAN, and complications of immunosuppression were assessed. BKV DNAemia decreased faster and significantly in the control group as compared to the mTORi±IVIg group (p < 0.001). Viral clearance was significantly higher in the control group compared to the mTORi±IVIg group (88% vs. 58%; p = 0.033). Death-censored graft loss, rejection rates and kidney-graft function at 12 months did not significantly differ. Multivariate analyses significantly associated BKV DNAemia clearance with reducing immunosuppression (OR = 0.11 (0.06−0.9), p = 0.045), female kidney donor (OR = 0.10 (0.01−0.59/)], p = 0.018) and time to first DNAemia, (OR = 0.88 (0.76−0.96), p = 0.019). In our study, the standard treatment for BKV DNAemia had better outcomes than an mTORi±IVIg conversion.

Main Targets of Interest for the Development of a Prophylactic or Therapeutic Epstein-Barr Virus Vaccine.

Epstein-Barr virus (EBV) is one of the most widespread viruses in the world; more than 90% of the planet's adult population is infected. Symptomatic primary infection by this Herpesviridae corresponds to infectious mononucleosis (IM), which is generally a benign disease. While virus persistence is often asymptomatic, it is responsible for 1.5% of cancers worldwide, mainly B cell lymphomas and carcinomas. EBV may also be associated with autoimmune and/or inflammatory diseases. However, no effective treatment or anti-EBV vaccine is currently available. Knowledge of the proteins and mechanisms involved in the different steps of the viral cycle is essential to the development of effective vaccines. The present review describes the main actors in the entry of the virus into B cells and epithelial cells, which are targets of interest in the development of prophylactic vaccines aimed at preventing viral infection. This review also summarizes the first vaccinal approaches tested in humans, all of which are based on the gp350/220 glycoprotein; while they have reduced the risk of IM, they have yet to prevent EBV infection. The main proteins involved in the EBV latency cycle and some of the proteins involved in the lytic cycle have essential roles in the oncogenesis of EBV. For that reason, these proteins are of interest for the development of therapeutic vaccines of which the objective is the stimulation of T cell immunity against EBV-associated cancers. New strategies aimed at broadening the antigenic spectrum, are currently being studied and will contribute to the targeting of the essential steps of the viral cycle, the objective being to prevent or treat the diseases associated with EBV.