Two cases of misleading Epstein-Barr virus infection and the role of EBV-DNA.

Two atypical cases of infectious mononucleosis in two teenagers with initially negative serology and non-evocative blood examinations are reported. The first patient had recently traveled to Africa, and Epstein-Barr virus negative serology led us to make many extensive investigations. The second patient complained of asthenia for a month, and PET/CT was performed to suspicion of lymphoma. PET scan revealed hypermetabolic lymph nodes in the supradiaphragmatic and subdiaphragmatic stations, along with18F-FDG uptake in the spleen and pharynx, raising more suspicion of lymphoma. Fortunately, Epstein-Barr virus DNA testing was performed and turned positive in both cases, and Epstein-Barr virus serology subsequently became positive. Diagnosing EBV infection can be challenging in rare cases, as EBV-specific serology may be negative in the early stages and confounding factors may be present. Therefore, Epstein-Barr virus DNA testing should be considered early in the diagnostic algorithm to prevent unnecessary investigations in similar cases.

Outcomes and Predictors of Mortality in Patients With KPC-Kp Infections Treated With Meropenem Vaborbactam: An Observational Multicenter Study.

Background: Meropenem-vaborbactam is a recent and promising option for the treatment of KPC-producing Klebsiella pneumoniae (KPC-Kp) infections, including those resistant to ceftazidime-avibactam. Methods: We conducted a retrospective analysis of observational data from 19 Italian hospitals on use and outcomes of patients treated with meropenem-vaborbactam for at least ≥24 hours for KPC-Kp infections. Crude and propensity-weighted multiple Cox regression models were performed to ascertain risk factors independently associated with 30-day mortality. Results: The cohort included 342 adults with bloodstream infections (n = 172) and nonbacteremic infections (n = 170), of which 107 were lower respiratory tract infections, 30 were complicated urinary tract infections, and 33 were infections involving other sites. Most infections (62.3%) were managed with meropenem-vaborbactam monotherapy, or in combination with at least 1 other active drug (usually fosfomycin, tigecycline, or gentamicin) (37.7%). The 30-day mortality rate was 31.6% (108/342). In multiple Cox regression model, 30-day mortality was independently associated with septic shock at infection onset, Charlson comorbidity index ≥ 3, dialysis, concomitant COVID-19, and INCREMENT score ≥ 8. Administration of meropenem-vaborbactam within 48 hours from infection onset was a negative predictor of mortality. All predictors, except administration of meropenem-vaborbactam within 48 hours, remained significant when the multiple Cox regression model was repeated after adjustment for the propensity score for receipt of combination therapy. Conclusions: Despite the limits of a retrospective study, the data derived from this multicenter cohort provide additional evidence on the efficacy of meropenem-vaborbactam in treating severe KPC-Kp infections, even when used as monotherapy.

Screening for Latent Tuberculosis Infection in People Living with HIV: TUBHIVIT Project, a Multicenter Italian Study.

BACKGROUND: The coexistence of HIV infection and latent tuberculosis infection (LTBI) presents a significant public health concern due to the increased risk of tuberculosis (TB) reactivation and progression to active disease. The multicenter observational cohort study, TUBHIVIT, conducted in Italy from 2017 to 2023, aimed to assess the prevalence of LTBI among people living with HIV (PLHIV) and their outcomes following LTBI screening and therapy initiation. METHODS: We performed a prospective study in five referral centers for HIV care in Italy. PLHIV who consented Tto participate underwent QuantiFERON-TB Gold Plus and clinical, microbiological, and radiological assessments to exclude subclinical tuberculosis, as opportune. PLHIV diagnosed with LTBI who started chemoprophylaxis were followed until the end of therapy. RESULTS: A total of 1105 PLHIV were screened for LTBI using the QuantiFERON-TB Gold Plus test, revealing a prevalence of 3.4% of positive results (38/1105). Non-Italy-born individuals exhibited a significantly higher likelihood of testing positive. Thirty-one were diagnosed with LTBI, 1 showed active subclinical TB, and 6 were lost to follow-up before discriminating between latent and active TB. Among the PLHIV diagnosed with LTBI, 83.9% (26/31) started chemoprophylaxis. Most individuals received 6-9 months of isoniazid-based therapy. Of the 26 PLHIV commencing chemoprophylaxis, 18 (69.2%) completed the therapy, while 3 discontinued it and 5 were still on treatment at the time of the analysis. Adverse events were observed in two cases, while in one case the patient refused to continue the treatment.

Efficacy of Respiratory Syncytial Virus Vaccination to Prevent Lower Respiratory Tract Illness in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

A systematic review and meta-analysis was designed in order to ascertain the effectiveness of respiratory syncytial virus (RSV) vaccination in preventing lower respiratory tract diseases (LRTD) in older adults (age ≥ 60 years). Studies reporting on randomized controlled trials (RCTs) were searched for in three databases (PubMed, Embase, and Scopus) and the preprint repository medRxiv until 31 March 2024. A total of nine studies were eventually included, two of which were conference proceedings. Our analysis included five RCTs on five RSV vaccines (RSVpreF, RSVPreF3, Ad26.RSV.preF, MEDI7510, and mRNA-1345). The meta-analysis documented a pooled vaccine efficacy of 81.38% (95% confidence interval (95% CI) 70.94 to 88.06) for prevention of LRTD with three or more signs/symptoms during the first RSV season after the delivery of the vaccine. Follow-up data were available for RSVPreF3 (2 RSV seasons), RSVpreF (mid-term estimates of second RSV season), and mRNA-1345 (12 months after the delivery of the primer), with a pooled VE of 61.15% (95% CI 45.29 to 72.40). After the first season, the overall risk for developing RSV-related LRTD was therefore substantially increased (risk ratio (RR) 4.326, 95% CI 2.415; 7.748). However, all estimates were affected by substantial heterogeneity, as suggested by the 95% CI of I2 statistics, which could be explained by inconsistencies in the design of the parent studies, particularly when dealing with case definition. In conclusion, adult RSV vaccination was quite effective in preventing LRTD in older adults, but the overall efficacy rapidly decreased in the second season after the delivery of the vaccine. Because of the heterogenous design of the parent studies, further analyses are required before tailoring specific public health interventions.

A Difficult Case of Ventriculitis in a 40-Year-Old Woman with Acute Myeloid Leukemia.

Ventriculitis and nosocomial meningitis caused by carbapenem-resistant Gram-negative and vancomycin-resistant Gram-positive bacteria represent a growing treatment challenge. A case of ventriculitis and bacteremia caused by carbapenem-resistant, KPC-producing Klebsiella pneumoniae and vancomycin-resistant Enterococcus faecium in a young woman with acute leukemia who was successfully treated with meropenem/vaborbactam (MVB), rifampicin, and linezolid is described in this paper. This case report emphasizes the importance of a multidisciplinary strategy, including infectious focus control, for the treatment of device-associated central nervous system (CNS) infections from multidrug-resistant bacteria. Considering the novel resistance patterns, more research on drug penetration into the central nervous system, as well as on the necessity of association therapies, is needed.

COVID-19: The Development and Validation of a New Mortality Risk Score.

Background: The coronavirus disease 2019 (COVID-19) pandemic has found the whole world unprepared for its correct management. Italy was the first European country to experience the spread of the SARS-CoV-2 virus at the end of February 2020. As a result of hospital overcrowding, the quality of care delivered was not always optimal. A substantial number of patients admitted to non-ICU units could have been treated at home. It would have been extremely useful to have a score that, based on personal and clinical characteristics and simple blood tests, could have predicted with sufficient reliability the probability that a patient had or did not have a disease that could have led to their death. This study aims to develop a scoring system to identify which patients with COVID-19 are at high mortality risk upon hospital admission, to expedite and enhance clinical decision making. Methods: A retrospective analysis was performed to develop a multivariable prognostic prediction model. Results: Derivation and external validation cohorts were obtained from two Italian University Hospital databases, including 388 (10.31% deceased) and 1357 (7.68% deceased) patients with confirmed COVID-19, respectively. A multivariable logistic model was used to select seven variables associated with in-hospital death (age, baseline oxygen saturation, hemoglobin value, white blood cell count, percentage of neutrophils, platelet count, and creatinine value). Calibration and discrimination were satisfactory with a cumulative AUC for prediction mortality of 0.924 (95% CI: 0.893-0.944) in derivation cohorts and 0.808 (95% CI: 0.886-0.828) in external validation cohorts. The risk score obtained was compared with the ISARIC 4C Mortality Score, and with all the other most important scores considered so far, to evaluate the risk of death of patients with COVID-19. It performed better than all the above scores to evaluate the predictability of dying. Its sensitivity, specificity, and AUC were higher than the other COVID-19 scoring systems when the latter were calculated for the 388 patients in our derivation cohort. Conclusions: In conclusion, the CZ-COVID-19 Score may help all physicians by identifying those COVID-19 patients who require more attention to provide better therapeutic regimens or, on the contrary, by identifying those patients for whom hospitalization is not necessary and who could therefore be sent home without overcrowding healthcare facilities. We developed and validated a new risk score based on seven variables for upon-hospital admission of COVID-19 patients. It is very simple to calculate and performs better than all the other similar scores to evaluate the predictability of dying.

Risk of Cardiovascular Events in People with HIV (PWH) Treated with Integrase Strand-Transfer Inhibitors: The Debate Is Not Over; Results of the SCOLTA Study.

Cardiovascular disease (CVD) is common in people with HIV (PWH), and has great impact in terms of morbidity and mortality. Several intertwined mechanisms are believed to play a role in determining the increased risk of CVD, including the effect of certain antiretrovirals; among these, the role of integrase strand-transfer inhibitors (INSTIs) is yet to be fully elucidated. We conducted a multicenter, observational study comprising 4984 PWH evaluating the antiretroviral therapy (ART)-related nature of CVD in real life settings, both in naïve vs. treatment-experienced people. A comparison was conducted between INSTIs vs. either protease inhibitors (PIs) or non-nucleoside reverse transcriptase inhibitors (NNRTIs) considering demographic, baseline clinical characteristics, incidence of CVD in both 2-year and complete follow-up periods. Among 2357 PWH exposed to INSTIs, 24 people experienced CVD; the corresponding figure was 12 cases out of 2599 PWH exposed to other ART classes. At univariate and multivariate analysis, a tendency towards an increased risk of CVD was observed in the 2-year follow-up period in PWH exposed to INSTIs in the absence, however, of statistical significance. These findings leave open the hypothesis that INSTIs may play a role, albeit minimal, in determining an increased risk of CVD in PWH.

Sepsis in Patients Hospitalized in Sicily, Italy, over the Period of 2016-2020: A Retrospective Study.

Background: Epidemiological data regarding the incidence and mortality of sepsis are scarcely available. The present study aimed to delineate the epidemiology of sepsis and related mortality among patients hospitalized in Sicily, Italy. Methods: Data on the discharge forms of all patients with sepsis in all Sicilian hospitals from January 2016 to December 2020 were retrospectively collected. Results: In Sicily, 15,373 hospitalizations associated with sepsis occurred from 2016 to 2020, with an overall in-hospital mortality rate of 36.3%. The percentage of hospitalizations associated with sepsis represented 0.65% of all admissions, with an increase over the years. Most patients were admitted to non-surgical and non-infectious disease units, accounting for 50.3% of total admissions. Stratification of patients according to age, intensive care unit (ICU) admission, and presence of septic shock revealed variations in in-hospital mortality rates. Among adult ICU-admitted patients with septic shock, mortality was highest at 81.0%, followed by non-ICU adult patients with septic shock (63.5%), ICU pediatric patients with septic shock (56.7%), ICU adult patients without septic shock (43.9%), non-ICU pediatric patients with septic shock (37.9%), non-ICU adult patients without septic shock (17.9%), ICU pediatric patients without septic shock (10.4%), and non-ICU pediatric patients without septic shock (1%).

On the use of intravenous metronidazole for severe and complicated Clostridioides difficile infection: a review and meta-analysis.

The European Society of Clinical Microbiology and Infectious Disease (ESCMID) has advised against the use of metronidazole for fulminant Clostridioides difficile (C. difficile) infection (CDI) in their latest guidelines. They suggest using oral vancomycin alone instead. This recommendation is based on a few retrospective studies, which have multiple biases. We evaluated the three studies that led ESCMID to advise against intravenous metronidazole for fulminant CDI and performed a meta-analysis. The meta-analysis revealed a mild (2.7%), not statistically significant (p=0.8) difference in mortality between the two groups. The high heterogeneity (I2= 89%) should also be noted. The decision to add or remove metronidazole should be discussed in the near future. In the meantime, combination therapy could be a cautious treatment for fulminant CDI.

Acute Cytomegalovirus Infection Associated With Erythema Multiforme-Like Eruption: A Case Report.

Human cytomegalovirus infection usually proceeds asymptomatically in immunocompetent patients. In symptomatic forms, mononucleosis syndrome is the most common manifestation. However, atypical cases of cytomegalovirus infections in immunocompetent subjects are reported in the literature. Here, we describe a case of cytomegalovirus-related mononucleosis syndrome that presented with an atypical erythema multiforme-like skin rash and high fever. Very few cases have been described in the literature previously. In our case, the diagnosis was supported by specific serology, and human cytomegalovirus DNA was detected in the blood sample. The clinical picture resolved without the administration of antiviral therapy.

Microbial profile in bile from pancreatic and extra-pancreatic biliary tract cancer.

BACKGROUND: Dysbiotic biliary bacterial profile is reported in cancer patients and is associated with survival and comorbidities, raising the question of its effect on the influence of anticancer drugs and, recently, the suggestion of perichemotherapy antibiotics in pancreatic cancer patients colonized by the Escherichia coli and Klebsiella pneumoniae. OBJECTIVE: In this study, we investigated the microbial communities that colonize tumours and which bacteria could aid in diagnosing pancreatic and biliary cancer and managing bile-colonized patients. METHODS: A retrospective study on positive bile cultures of 145 Italian patients who underwent cholangiopancreatography with PC and EPC cancer hospitalized from January 2006 to December 2020 in a QA-certified academic surgical unit were investigated for aerobic/facultative-anaerobic bacteria and fungal organisms. RESULTS: We found that among Gram-negative bacteria, Escherichia coli and Pseudomonas spp were the most frequent in the EPC group, while Escherichia coli, Klebsiella spp, and Pseudomonas spp were the most frequent in the PC group. Enterococcus spp was the most frequent Gram-positive bacteria in both groups. Comparing the EPC and PC, we found a significant presence of patients with greater age in the PC compared to the EPC group. Regarding Candida spp, we found no significant but greater rate in the PC group compared to the EPC group (11.7% vs 1.96%). We found that Alcaligenes faecalis was the most frequent bacteria in EPC than the PC group, among Gram-negative bacterial species. CONCLUSIONS: Age differences in gut microbiota composition may affect biliary habitats in our cancer population, especially in patients with pancreatic cancer. Alcaligenes faecalis isolated in the culture of bile samples could represent potential microbial markers for a restricted follow-up to early diagnosis of extra-pancreatic cancer. Finally, the prevalence of Candida spp in pancreatic cancer seems to trigger new aspects about debate about the role of fungal microbiota into their relationship with pancreatic cancer.

Tuberculous Pericarditis in Childhood: A Case Report and a Systematic Literature Review.

Tuberculous pericarditis (TBP) is an important cause of pericarditis worldwide while being infrequent in childhood, especially in low-TB-incidence countries. We report a case of TBP and provide a systematic review of the literature, conducted by searching PubMed, Scopus, and Cochrane to find cases of TBP in pediatric age published in the English language between the year 1990 and the time of the search. Of the 587 search results obtained, after screening and a backward citation search, 45 studies were selected to be included in this review, accounting for a total of 125 patients. The main signs and symptoms were fever, cough, weight loss, hepatomegaly, dyspnea, and increased jugular venous pressure or jugular vein turgor. A definitive diagnosis of TBP was made in 36 patients, either thanks to microbiological investigations, histological analysis, or both. First-line antitubercular treatment (ATT) was administered in nearly all cases, and 69 children underwent surgical procedures. Only six patients died, and only two died of TBP. TBP in childhood is relatively uncommon, even in high-TB-prevalence countries. Clinical manifestations, often suggestive of right-sided cardiac failure, are subtle, and diagnosis is challenging. TBP has an excellent prognosis in childhood; however, in a significant proportion of cases, invasive surgical procedures are necessary.

Donor-derived carbapenem-resistant gram-negative bacterial infections in solid organ transplant recipients: Active surveillance enhances recipient safety.

Donor-derived infections (DDIs) caused by carbapenem-resistant gram-negative bacteria (CR-GNB) in solid organ transplant recipients are potentially life-threatening. In this prospective study, we evaluated the incidence, factors associated with transmission, and the outcome of recipients with unexpected CR-GNB DDIs after the implementation of our local active surveillance system (LASS). LASS provides for early detection of unexpected donor CR-GNB infections, prophylaxis of recipients at high risk, and early diagnosis and treatment of DDIs. Whole genome sequencing confirmed DDI. Among 791 recipients, 38 (4.8%) were at high risk of unexpected CR-GNB DDI: 25 for carbapenem-resistant Enterobacterales (CRE) and 13 for carbapenem-resistant Acinetobacter baumannii (CRAB). Transmission did not occur in 27 (71%) cases, whereas DDIs occurred in 9 of 25 of CRE and 2 of 13 of CRAB cases. Incidence of CR-GNB DDI was 1.4%. Recipients of organs with CR-GNB-positive preservation fluid and liver recipients from a donor with CRE infection were at the highest risk of DDI. There was no difference in length of hospital stay or survival in patients with and without CR-GNB DDI. Our LASS contains transmission and mitigates the negative impacts of CR-GNB DDI. Under well-defined conditions, organs from donors with CR-GNB may be considered after a thorough evaluation of the risk/benefit profile.

People with HIV pioneers of injectable cabotegravir and rilpivirine long acting in Italy: who are they?

Injectable cabotegravir and rilpivirine long-acting therapy is a revolutionary new antiretroviral treatment (ART) option for HIV infection in virologically suppressed adults on a stable ART. The aim of this study from SCOLTA multicenter observational prospective database is to describe the first people living with HIV (PWH) who started this regimen in Italy, assessing adherence to eligibility criteria, describing clinical-epidemiological characteristics compared to registration trials-population and describe early treatment-discontinuations.

Understanding clinical outcomes and factors influencing mortality in intensive care unit patients with COVID-19-associated candidemia.

BACKGROUND: During the COVID pandemic, research has shown an increase in candidemia cases following severe COVID infection and the identification of risk factors associated with candidemia. However, there is a lack of studies that specifically explore clinical outcomes and mortality rates related to candidemia after COVID infection. OBJECTIVES: The aim of this international study was to evaluate the clinical outcomes and identify factors influencing mortality in patients who developed candidemia during their COVID infection. PATIENTS/METHODS: This study included adult patients (18 years of age or older) admitted to the intensive care unit (ICU) and diagnosed with COVID-associated candidemia (CAC). The research was conducted through ID-IRI network and in collaboration with 34 medical centres across 18 countries retrospectively, spanning from the beginning of the COVID pandemic until December 2021. RESULTS: A total of 293 patients diagnosed with CAC were included. The median age of the patients was 67, and 63% of them were male. The most common Candida species detected was C. albicans. The crude 30-day mortality rate was recorded at 62.4%. The logistic regression analysis identified several factors significantly impacting mortality, including age (odds ratio [OR] 1.04, 95% confidence interval [CI] 1.02-1.07, p < .0005), SOFA score (OR 1.307, 95% CI 1.17-1.45, p < .0005), invasive mechanical ventilation (OR 7.95, 95% CI 1.44-43.83, p < .017) and duration of mechanical ventilation (OR 0.98, 95% CI 0.96-0.99, p < .020). CONCLUSIONS: By recognising these prognostic factors, medical professionals can customise their treatment approaches to offer more targeted care, leading to improved patient outcomes and higher survival rates for individuals with COVID-associated candidemia.

Dalbavancin real-life utilization among diabetic patients suffering from infections in Italy and Spain: The DALBADIA retrospective cohort study.

OBJECTIVES: To retrospectively describe the patterns of use of dalbavancin for treating infections in diabetic patients in Italian and Spanish standard clinical practice. METHODS: DALBADIA [NCT04959799] was a multicentre, observational, retrospective cohort study, conducted in Italy and Spain. The study enrolled 97 adults with type 1 or 2 diabetes mellitus, treated with dalbavancin as per standard clinical practice for a Gram-positive bacterial infection or the Gram-positive component of a mixed infection. RESULTS: Dalbavancin was used to treat cellulitis (18/92 patients, 19.6%), followed by prosthetic joint infection (14 patients, 15.2%), endocarditis (13 patients, 14.1%), and primary bacteraemia (10 patients, 10.9%); 78/92 (84.8%) patients had Gram-positive infections only, and 14 (15.2%) had mixed infections. The most frequently isolated microorganisms were Staphylococcus aureus in 43 (55.8% of the patients with microbial isolation), 25.6% of which methicillin-resistant; Staphylococcus epidermidis in 13 (16.9%), 53.8% of which methicillin-resistant; Enterococcus faecalis in 11 (14.3%). The main reason for the dalbavancin choice was the intent to simplify the antibiotic regimen (81.5% of cases). A multidisciplinary team participated in the treatment choice process for 53 (57.6%) patients. Dalbavancin was given as first-line antibiotic in 34 (37.0%) patients and administered as one infusion in 32 (34.8%), and as two infusions in 39 (42.4%). In total, 57/62 (91.9%) eligible patients with available assessment were judged clinically cured or improved at the end of observation. CONCLUSION: In clinical practice, dalbavancin was used in diabetic patients to treat ABSSSIs and other difficult-to-treat infections with a favourable safety profile and a high rate of positive clinical responses.

Intravenous Fosfomycin for Systemic Multidrug-Resistant Pseudomonas aeruginosa Infections.

Human Pseudomonas infections have high morbidity and mortality rates. Pseudomonas bacteria can cause sepsis or septic shock; they produce biofilm and commonly exhibit a multidrug-resistant phenotype. The choice of antimicrobial therapy in many cases is challenging, and deep knowledge of clinical, microbiological, and pharmacological issues is required. Intravenous fosfomycin is being repurposed in a combination given its favorable pharmacokinetic/pharmacodynamic properties (a small molecule with favorable kinetic both in bloodstream infection and in deep-seated infections), antibiofilm activity, and its interesting synergistic effects with other antimicrobials. Recent literature on epidemiological, microbiological, pharmacological, and clinical data on intravenous fosfomycin therapy against Pseudomonas is herein reviewed and discussed.

An Uncommon Case of Syphilis With Simultaneous, Different Lesions: Moth-Eaten Alopecia, Syphilitic Keratoderma, and Psoriasiform Syphilis.

Syphilis is a re-emerging disease, and an increasing number of cases are being reported in Italy and worldwide. In this report, we present a case of a male patient with secondary syphilis characterized by the heterogenicity of the lesions: hyperkeratosis, psoriasiform-like lesions, papules, macules, and patchy alopecia on the scalp. The patient had applied several topical antimicrobials and steroid medicaments and taken oral acyclovir, which yielded no relief, for a previous wrong diagnosis. At the time of his presentation to our clinic, syphilis was suspected and confirmed by serology. The administration of a single intramuscular dose of penicillin led to a full recovery in three weeks. Screening for HIV and other sexually transmitted infections returned negative. Clinicians should maintain a high index of suspicion for syphilis when encountering sexually active patients with atypical skin manifestations.

SARS-CoV-2 mRNA Vaccine Response in People Living with HIV According to CD4 Count and CD4/CD8 Ratio.

BACKGROUND: Our aim was to estimate the rates of not achieving a robust/above-average humoral response to the COVID-19 mRNA vaccine in people living with HIV (PLWH) who received ≥2 doses and to investigate the role of the CD4 and CD4/CD8 ratio in predicting the humoral response. METHODS: We evaluated the humoral anti-SARS-CoV-2 response 1-month after the second and third doses of COVID-19 mRNA vaccine as a proportion of not achieving a robust/above-average response using two criteria: (i) a humoral threshold identified as a correlate of protection against SARS-CoV-2 (<90% vaccine efficacy): anti-RBD < 775 BAU/mL or anti-S < 298 BAU/mL, (ii) threshold of binding antibodies equivalent to average neutralization activity from the levels of binding (nAb titer < 1:40): anti-RBD < 870 BAU/mL or anti-S < 1591 BAU/mL. PLWH were stratified according to the CD4 count and CD4/CD8 ratio at first dose. Logistic regression was used to compare the probability of not achieving robust/above-average responses. A mixed linear model was used to estimate the mean anti-RBD titer at various time points across the exposure groups. RESULTS: a total of 1176 PLWH were included. The proportions of participants failing to achieve a robust/above-average response were significantly higher in participants with a lower CD4 and CD4/CD8 ratio, specifically, a clearer gradient was observed for the CD4 count. The CD4 count was a better predictor of the humoral response of the primary cycle than ratio. The third dose was pivotal in achieving a robust/above-average humoral response, at least for PLWH with CD4 > 200 cells/mm3 and a ratio > 0.6. CONCLUSIONS: A robust humoral response after a booster dose has not been reached by 50% of PLWH with CD4 < 200 cells mm3. In the absence of a validated correlate of protections in the Omicron era, the CD4 count remains the most solid marker to guide vaccination campaigns in PLWH.