Role of Direct Sexual Contact in Human Transmission of Monkeypox Virus, Italy.

The 2022 global mpox outbreak was driven by human-to-human transmission, but modes of transmission by sexual relationship versus sexual contact remain unclear. We evaluated sexual transmission of mpox by using monkeypox virus (MPXV) G2R-mRNA as a marker of ongoing viral replication through in vitro experiments. We analyzed clinical samples of 15 MPXV-positive patients in Italy from different biological regions by using the setup method. The presence of MPXV DNA, MPXV G2R-mRNA, or both in all analyzed lesion swab samples, independent of viral load, confirmed a higher infectivity risk from skin lesions. Positivity for MPXV G2R-mRNA in nasopharyngeal swabs was associated with high MPXV load, whereas positive results for MPXV G2R-mRNA were obtained only in the 2 semen samples with the lowest MPXV loads. Our results suggest that close or skin-to-skin contact during sexual intercourse is the main route of sexual transmission and that semen is a minor driver of infection, regardless of MPXV load.

HIV-1 transmitted drug resistance in newly diagnosed individuals in Italy over the period 2015-21.

BACKGROUND: Transmitted drug resistance (TDR) is still a critical aspect for the management of individuals living with HIV-1. Thus, its evaluation is crucial to optimize HIV care. METHODS: Overall, 2386 HIV-1 protease/reverse transcriptase and 1831 integrase sequences from drug-naïve individuals diagnosed in north and central Italy between 2015 and 2021 were analysed. TDR was evaluated over time. Phylogeny was generated by maximum likelihood. Factors associated with TDR were evaluated by logistic regression. RESULTS: Individuals were mainly male (79.1%) and Italian (56.2%), with a median (IQR) age of 38 (30-48). Non-B infected individuals accounted for 44.6% (N = 1065) of the overall population and increased over time (2015-2021, from 42.1% to 51.0%, P = 0.002). TDR prevalence to any class was 8.0% (B subtype 9.5% versus non-B subtypes 6.1%, P = 0.002) and remained almost constant over time. Overall, 300 transmission clusters (TCs) involving 1155 (48.4%) individuals were identified, with a similar proportion in B and non-infected individuals (49.7% versus 46.8%, P = 0.148). A similar prevalence of TDR among individuals in TCs and those out of TCs was found (8.2% versus 7.8%, P = 0.707).By multivariable analysis, subtypes A, F, and CFR02_AG were negatively associated with TDR. No other factors, including being part of TCs, were significantly associated with TDR. CONCLUSIONS: Between 2015 and 2021, TDR prevalence in Italy was 8% and remained almost stable over time. Resistant strains were found circulating regardless of being in TCs, but less likely in non-B subtypes. These results highlight the importance of a continuous surveillance of newly diagnosed individuals for evidence of TDR to inform clinical practice.

Poor durability of the neutralizing response against XBB sublineages after a bivalent mRNA COVID-19 booster dose in persons with HIV.

We estimated the dynamics of the neutralizing response against XBB sublineages and T cell response in persons with HIV (PWH) with previous AIDS and/or CD4 < 200/mm3 receiving the bivalent original strain/BA.4-5 booster dose in fall 2022. Samples were collected before the shot (Day 0), 15 days, 3, and 6 months after. PWH were stratified by immunization status: hybrid immunity (HI; vaccination plus COVID-19) versus nonhybrid immunity (nHI; vaccination only). Fifteen days after the booster, 16% and 30% of PWH were nonresponders in terms of anti-XBB.1.16 or anti-EG.5.1 nAbs, respectively. Three months after, a significant waning of anti-XBB.1.16, EG.5.1 and -XBB.1 nAbs was observed both in HI and nHI but nAbs in HI were higher than in nHI. Six months after both HI and nHI individuals displayed low mean levels of anti-XBB.1.16 and EG.5.1 nAbs. Regarding T cell response, IFN-γ values were stable over time and similar in HI and nHI. Our data showed that in PWH, during the prevalent circulation of the XBB.1.16, EG.5.1, and other XBB sublineages, a mRNA bivalent vaccine might not confer broad protection against them. With a view to the 2023/2024 vaccination campaign, the use of the monovalent XBB.1.5 mRNA vaccine should be urgently warranted in PWH to provide adequate protection.

Molnupiravir increases SARS-CoV-2 genome diversity and complexity: A case-control cohort study.

Molnupiravir, an oral direct-acting antiviral effective in vitro against SARS-CoV-2, has been largely employed during the COVID-19 pandemic, since December 2021. After marketing and widespread usage, a progressive increase in SARS-CoV-2 lineages characterized by a higher transition/transversion ratio, a characteristic signature of molnupiravir action, appeared in the Global Initiative on Sharing All Influenza Data (GISAID) and International Nucleotide Sequence Database Collaboration (INSDC) databases. Here, we assessed the drug effects by SARS-CoV-2 whole-genome sequencing on 38 molnupiravir-treated persistently positive COVID-19 outpatients tested before and after treatment. Seventeen tixagevimab/cilgavimab-treated outpatients served as controls. Mutational analyses confirmed that SARS-CoV-2 exhibits an increased transition/transversion ratio seven days after initiation of molnupiravir. Moreover we observed an increased G->A ratio compared to controls, which was not related to apolipoprotein B mRNAediting enzyme, catalytic polypeptide-like (APOBEC) activity. In addition, we demonstrated for the first time an increased diversity and complexity of the viral quasispecies.

Determinants of worse liver-related outcome according to HDV infection among HBsAg positive persons living with HIV: Data from the ICONA cohort.

OBJECTIVES: We aimed to study hepatitis D virus (HDV) prevalence and risk of progression to severe liver-related events (SLRE) in HBsAg positive people living with HIV (PLWH) in Italy; role of HDV-RNA copy levels, HCV coinfection and nadir CD4 counts were also investigated. METHODS: People living with HIV (PLWH) from Italian Foundation cohort Naïve antiretrovirals (ICONA) with available HBsAg and HDV Ab were enrolled. HBsAg, HDV Ab, HDV-RNA and HDV genotypes were tested. PRIMARY END-POINT: time from first HDV screening to Severe Liver Related Events (SLRE: decompensated cirrhosis, liver transplantation, HCC). Fine-grey regression models were used to evaluate the association of HDV Ab, HDV-RNA, HDV/HCV coinfection, CD4 nadir and outcome. Secondary end-points: time to SLRE or death; HDV Ab and HDV-RNA prevalence. RESULTS: A total of 152/809 (18.8%) HBsAg positive PLWH showed HDV Ab reactivity; 63/93 (67.7%) were HDV-RNA positive. Being male, persons who inject drugs (PWID), HCV Ab positive, with FIB-4 > 3.25 were independent factors of HDV Ab positivity. In a median follow-up of 5 years, 37 PLWH (4.1% at 5-year) developed SLRE and 97 (12.0%) reached the SLRE or death end-point. HDV-RNA positive (independently from HDV-RNA copy level) PLWH had a 4.6-fold (95%CI 2.0-10.5) higher risk of SLRE than HDV negatives. PLWH positive for both HCV Ab and HDV Ab showed the highest independent risk of SLRE (ASHR: 11.9, 95%CI: 4.6-30.9 vs. HCV neg/HDV neg). Nadir CD4 < 200/mL was associated with SLRE (ASHR: 3.9, 95% 1.0-14.5). CONCLUSIONS: One-fifth of the HBsAg positive PLWH harbour HDV infection, and are at high risk of progression to advanced liver disease. HCV contributes to worse outcomes. This population needs urgently effective treatments.

Concomitant Syndromic Diagnosis of Mpox and Other Vesicular Viruses in Patients with Skin and Genital Lesions.

The recent multi-country outbreak of the zoonotic monkeypox virus (MPXV) infection in humans without an epidemiological link with endemic areas has raised concerns about the route of transmission. Since the infection spread largely among men who have sex with men who, in most cases, presented primary lesions of the genital and oral mucosa, sexual transmission has been proposed. In the present study, we retrospectively evaluated specimens of vesicular lesions collected from the skin and genital tract of 35 patients (23 positive and 12 negative) presenting at our Institute for monkeypox (mpox) diagnosis by using a novel molecular syndromic vesicular virus panel (VVP) assay. All MPXV-positive samples but one was confirmed; however, the viral syndromic analysis revealed that 8.6% of them were coinfected with one or more viruses, and 17% had at least a virus different from the MPXV. The percentage of coinfections increased to more than 25% when nonviral pathogens, such as gonorrhea and syphilis, were also considered. These results show the usefulness of syndromic diagnosis in cases where MPXV is suspected (and vice versa) and at the same time highlight that the broader screening of sexually transmitted infections in the population with high-risk sexual behavior is critical to ensure a complete etiology and appropriate treatment.

Brief Report: In cART-Treated HIV-Infected Patients, Immunologic Failure Is Associated With a High Myeloid-Derived Suppressor Cell Frequency.

BACKGROUND: During HIV infection, effective combined antiretroviral therapy suppresses viral replication and restores the number of circulating CD4+ T cells. However, 15%-30% of treated patients show a discordant response to combined antiretroviral therapy. Myeloid-derived suppressor cells (MDSC) are expanded in HIV+ patients; to better understand the role of MDSC on CD4 T-cell recovery, we evaluated the frequency of MDSC in HIV+ patients under combined antiretroviral therapy and its association with immunologic response. METHODS: We enrolled 60 HIV+ patients, including complete responders (R, n = 44), virologic nonresponders (VNR, n = 5), and immunologic nonresponders (INR, n = 11). The frequency of circulating MDSC and the percentage of activated and naïve CD4 T cells were evaluated by flow cytometry. Plasmatic cytokine levels were analyzed by automated ELISA. RESULTS: As previously observed, polymorphonuclear MDSC (PMN-MDSC) frequency was higher in HIV+ patients compared with healthy donors. Furthermore, PMN-MDSC percentage was higher in INR than R patients, and a significant association between MDSC frequency and immunologic failure was confirmed by a receiver operator characteristic analysis. Accordingly, an inverse correlation was found between the percentages of PMN-MDSC and naïve CD4 T cells. A positive correlation was observed between PMN-MDSC frequency and the percentage of human leucocyte antigen locus DR + CD4 T cells and the plasmatic level of IL-1ß and IL-8. CONCLUSION: Our results show that a high frequency of PMN-MDSC persists in INR, possibly because of immune activation, contributing to CD4 T-cell recovery failure. These findings further highlight the detrimental role of MDSC during HIV infection, suggesting these cells as a possible new therapeutic target.

Human and Viral microRNA Expression in Acute and Chronic HIV Infections.

Human and viral microRNAs (miRNAs) are involved in the regulation of gene transcription, and the establishment of their profiles in acute (AHI) and chronic (CHI) HIV infections may shed light on the pathogenetic events related to different phases of HIV disease. Next-generation sequencing (NGS) of miRNA libraries was performed, and the reads were used to analyze miRNA differential expression in the plasma with AHI and CHI. Functional analysis was then undertaken to investigate the biological processes characterizing the two phases of HIV infection. Except for hsa-miR-122-5p, which was found in 3.39% AHI vs. 0.18% CHI, the most represented human miRNAs were similarly represented in AHI and CHI. However, when considering the overall detected miRNAs in AHI and CHI, 15 displayed differential expression (FDR p < 0.05). Functional analysis identified 163 target mRNAs involved in promoting angiogenesis activation in AHI versus CHI through the action of hsa-miR10b-5p, hsa-miR1290, hsa-miR1-3p, and hsa-miR296-5p. The viral miRNAs detected, all belonging to herpesviruses, accounted for only 0.014% of total reads. The present data suggest that AHI patients exhibit strong innate immune activation through the upregulation of hsa-miR-122-5p and early activation of angiogenesis. More specific investigations are needed to study the role of viral miRNAs in HIV pathogenesis.

Impact of COVID-19 pandemic on retention in care of native and migrant people with HIV in the ICONA cohort.

BACKGROUND: COVID-19 pandemic challenged the UNAIDS 90-90-90 targets. How the COVID-19 pandemic affected HIV retention in care and whether it has disproportionally affected migrant people with HIV (PWH) remained to be investigated. METHODS: PWH in ICONA Cohort in follow-up in each of the study periods were included: 01/09/2019-29/02/2020 (pandemic period) and 01/03/2018-31/08/2018 (historical period, as a control). Risk of temporary loss to follow-up (LTFU, defined as no data recorded for a person for one year) was analyzed by logistic regression, with migrant status as the main exposure variable. Difference in difference (DID) analysis was applied to evaluate the effect of COVID-19 pandemic in the different risk of LTFU between natives and migrants. RESULTS: 8864 (17.1% migrants) and 8071 (16.8% migrants) PWH constituted the pandemic and the historical period population, respectively. Proportion of PWH defined as LTFU in the pandemic period was 10.5% in native and 19.6% in migrant PWH. After controlling for age, sex and geographical location of enrolling site, risk of temporary LTFU was higher for migrants than native PWH [adjusted odds ratio 1.85 (95%CI 1.54-2.22)] in pandemic period. In PWH contributing to both periods, LTFU was 9.0% (95% CI 8.3-9.8) in natives vs 17.0% (95% CI 14.7-19.4) in migrants during the pandemic. Instead, LTFU was 1.2% (95%CI 0.9, 1.5) in natives vs 2.2% (95% CI 1.3-3.1) in migrants during the historical period, with a resulting DID of 7.0% (95% CI 4.4-9.6). CONCLUSIONS: A greater proportion of LTFU in migrant PWH was observed in both periods, which remained unaltered over time. Interventions to reduce LTFU of migrants are necessary.

SARS-CoV-2 mRNA vaccination and short-term changes in viral load and CD4/CD8 T-cell counts in people living with HIV.

OBJECTIVES: To investigate whether SARS-CoV-2 messenger RNA (mRNA) vaccination has an impact on HIV-related viro-immunological parameters. METHODS: People with HIV (PWH) in the VAXICONA-ORCHESTRA cohort who received one or more doses of SARS-CoV-2 mRNA vaccine and for whom paired measures of immuno-virological markers (viral load, clusters of differentiation [CD]4, and CD8 count 1 month before and after a vaccine dose [VD]) were available were included. Paired t-test and generalized estimating equation linear regression analyses were used to study changes over ± 1 month around the VD. Subgroup analyses were performed. RESULTS: A total of 510 PWH were enrolled: the median age was 55 years (interquartile range 46-60 years), the CD4 and CD8 count were 489 (287-719) and 790 (59-1104) cells/mm3, respectively, and 81% received three VDs. After a median of 28 (3-53) days from VD, CD4 count increased by +15 cells/mm3 (SD ± 129.7, P = 0.001) and CD8 by +12 (±250.5, P = 0.199) and the viral load decreased by -0.11 log10 (±0.88, P = 0.001). Similar results were observed after restricting the analysis to viro-suppressed PWH, with CD4 ≤200/mm3, more than 6 months of antiretroviral therapy before VD and after excluding previous COVID-19. CONCLUSIONS: A small significant increase in CD4 count and a negligible drop in HIV RNA were observed. Our findings are consistent with the hypothesis that SARS-CoV-2 mRNA vaccine can prime CD4 T spike-specific cells, even in the more immuno-compromised PWH.

Risk of SARS-CoV-2 infection in patients with hematologic diseases receiving tixagevimab/cilgavimab as pre-exposure prophylaxis in most recent Omicron sublineages era.

OBJECTIVES: Whether pre-exposure prophylaxis (PrEP) with tixagevimab/cilgavimab 150 mg/150 mg (T/C) in individuals with hematologic disease (HD) may lead to a reduced risk of SARS-CoV-2 breakthrough infection (BTI)/hospitalization, or death in the Omicron era remains to be established. METHODS: An observational study included participants with HD who received PrEP. BTIs were defined as SARS-CoV-2 positivity by reverse transcription-polymerase chain reaction. The incidence of BTIs (95% CI) and of BTIs/hospitalization/death was calculated using the Kaplan-Meier method and as the number of BTIs per 100 person-years of follow-up according to the circulating variant of concern (VoC). A Poisson regression model was used to evaluate the association between the rate of incidence and circulating VoCs after controlling for demographics and clinical factors. RESULTS: We included 550 HD patients: 71% initiated T/C PrEP when BA.5 was the most prevalent, followed by XBB/EG, BA.2, and BA.1 (19%, 7%, and 3%, respectively). Overall, the 1-year incidence estimate of BTIs/hospitalization/death was 24% (18.7-29.4%). A greater risk of incident infections was observed when BA.5 and XBB/EG sub-lineages circulated (aRR 5.05 [2.17, 11.77]; P < .001 and 3.82 [1.50, 9.7]; P = 0.005, compared to BA.1, respectively). CONCLUSIONS: The 1-year incidence of SARS-CoV-2 BTIs/hospitalization/death was 24% which is in line with what was observed in other similar studies. The risk appeared to be higher when more recent Omicron sub-lineages were circulating suggesting a reduction of in vitro neutralization.

Saliva Is a Sensitive and Accessible Sample Both for SARS-CoV-2 Detection and for the Evaluation of Treatment Effectiveness in Follow-Up Studies.

Despite emerging evidence indicating that molecular SARS-CoV-2 tests performed on saliva have diagnostic sensitivity and specificity comparable to those observed with nasopharyngeal swabs (NPSs), most in vivo follow-up studies on the efficacy of drugs against SARS-CoV-2 have been performed on NPSs, not considering saliva as a possible alternative matrix. For this reason, in this study, we used, in parallel, saliva and NPS samples for the detection of SARS-CoV-2 by real-time RT-PCR in patients receiving Tixagevimab/Cilgavimab, Nirmatrelvir/Ritonavir, or Sotrovimab as a treatment against SARS-CoV-2. Our results showed a good correlation between the NPS and saliva samples for each drug; moreover, comparable changes in the cycle threshold (Ct) levels in saliva and NPSs were observed both 7 days and 30 days after treatment, thus confirming that the saliva represents a good matrix for in vivo follow-up studies verifying the effectiveness of treatments against SARS-CoV-2.

Pharmacokinetics of tecovirimat in subjects with Mpox.

OBJECTIVE: To investigate the pharmacokinetics (PK) of tecovirimat in subjects with Mpox. METHODS: This monocentric, prospective, observational study enrolled subjects with Mpox who received standard treatment with oral tecovirimat. Plasma samples for PK assessment were collected at steady state (5-8 days after initiation of antiviral therapy), before and 3, 5, 7 and 12 h after tecovirimat administration. Drug concentrations were determined by validated liquid chromatography coupled with tandem mass spectrometry. PK parameters were calculated using Phoenix 8.1. RESULTS: Overall, 14 male patients hospitalized for severe Mpox with ongoing tecovirimat treatment were enrolled in this study. Six of the 14 patients were living with human immunodeficiency virus (HIV), all of whom were on antiretroviral therapy (ART) and virologically suppressed at the time of hospitalization. Significant differences in tecovirimat PK were observed in subjects without HIV compared with subjects with HIV. In subjects with HIV, the maximum tecovirimat plasma concentration (39%, P≤0.0001), minimum tecovirimat plasma concentration (42%, P=0.0079) and area under the curve from zero to the last measured time-point (40%, P≤0.0001) were significantly lower compared with subjects without HIV, but all concentrations remained above the in-vitro calculated 90% inhibitory concentration. No significant associations were found between demographic/clinical data and tecovirimat PK. All patients recovered completely within 14 (range 6-36) days of treatment initiation. CONCLUSIONS: This study found a significant decrease in plasma exposure of tecovirimat in Mpox patients with HIV on effective ART compared with those without HIV, with no evident impact on clinical outcomes. Although these results need to be confirmed in larger studies, they may provide useful information on the PK of tecovirimat.

MPXV DNA kinetics in bloodstream and other body fluids samples.

Since spring 2022, the global epidemiology of the monkeypox virus (MPXV) has changed. The unprecedented increase of human clade II MPXV cases worldwide heightened concerns about this emerging zoonotic disease. We analysed the positivity rates, viral loads, infectiousness, and persistence of MPXV DNA for up to 4 months in several biological samples from 89 MPXV-confirmed cases. Our data showed that viral loads and positivity rates were higher during the first two weeks of symptoms for all sample types. Amongst no-skin-samples, respiratory specimens showed higher MPXV DNA levels and median time until viral clearance, suggesting their usefulness in supporting MPXV diagnosis, investigating asymptomatic patients, and monitoring viral shedding. Infectious virus was cultured from respiratory samples, semen, and stools, with high viral loads and collected within the first 10 days. Notably, only one saliva and one semen were found positive for viral DNA after 71 and 31 days from symptoms, respectively. The focus on bloodstream samples showed the best testing sensitivity in plasma, reporting the overall highest MPXV DNA detection rate and viral loads during the 3-week follow-up as compared to serum and whole-blood. The data here presented can be useful for MPXV diagnostics and a better understanding of the potential alternative routes of its onward transmission.

Development and validation of a prediction score for failure to casirivimab/imdevimab in hospitalized patients with COVID-19 pneumonia.

Introduction: Casirivimab and imdevimab (CAS/IMV) are two non-competing, high-affinity human IgG1 anti-SARS-CoV-2 monoclonal antibodies, that showed a survival benefit in seronegative hospitalized patients with COVID-19. This study aimed to estimate the day-28 risk of mechanical ventilation (MV) and death in individuals hospitalized for severe COVID-19 pneumonia and receiving CAS/IMV. Additionally, it aimed to identify variables measured at the time of hospital admission that could predict these outcomes and derive a prediction algorithm. Methods: This is a retrospective, observational cohort study conducted in 12 hospitals in Italy. Adult patients who were consecutively hospitalized from November 2021 to February 2022 receiving CAS/IMV were included. A multivariable logistic regression model was used to identify predictors of MV or death by day 28 from treatment initiation, and ß-coefficients from the model were used to develop a risk score that was derived by means of leave-one-out internal cross-validation (CV), external CV, and calibration. Secondary outcome was mortality. Results: A total of 480 hospitalized patients in the training set and 157 patients in the test set were included. By day 28, 36 participants (8%) underwent MV and 28 died (6%) for a total of 58 participants (12%) experiencing the composite primary endpoint. In multivariable analysis, four factors [age, PaO2/FiO2 ratio, lactate dehydrogenase (LDH), and platelets] were independently associated with the risk of MV/death and were used to generate the proposed risk score. The accuracy of the score in the area under the curve (AUC) was 0.80 and 0.77 in internal validation and test for the composite endpoint and 0.87 and 0.86 for death, respectively. The model also appeared to be well calibrated with the raw data. Conclusion: The mortality risk reported in our study was lower than that previously reported. Although CAS/IMV is no longer used, our score might help in identifying which patients are not likely to benefit from monoclonal antibodies and may require alternative interventions.

Real World Use of Tixagevimab/Cilgavimab Pre-Exposure Prophylaxis of COVID-19 in Immunocompromised Individuals: Data from the OCTOPUS Study.

Objective. We aimed to report the real-world use and outcomes over time in immunocompromised individuals receiving tixagevimab/cilgavimab (T/C) pre-exposure prophylaxis (PrEP). Methods. This observational study included participants who received T/C PrEP, categorized into three groups: (i) No COVID-19 (NoC), i.e., participants who never had COVID-19; (ii) Hybrids (H), i.e., participants who had COVID-19 before PrEP; and (iii) Break-through Infections (BTIs), i.e., participants who had COVID-19 after PrEP. The study measured several immune markers at the administration of T/C (T0) at 3 (T1), 6 (T2), and 9 (T3) months afterward. These markers included: anti-receptor-binding domain (RBD) IgG antibodies; BA.5-neutralizing antibodies (nAbs); mucosal IgG; and T cell immunity. The incidence rate ratios for BTIs were analyzed using a Poisson regression model. Results. A total of 231 participants with a median age of 63 years (IQR 54.0-73.0). were included. Among these, 84% had hematological diseases and received a median of three vaccine doses. N = 72 participants belonged to the NoC group, N = 103 to the H group, and n = 56 to the BTI group (24%), with most BTIs being mild/moderate. The incidence rate (IR) of BTIs was 4.2 per 100 patient-months (95% CI 3.2-5.4), with no associated risk factors identified. There was a significant increase in anti-RBD IgG levels 3 months after the T/C administration in all groups, followed by a decline at 6 months, whereas at the same time points, geometric mean titers (GMTs) of anti-BA.5 nAbs were low for all groups and were around or below the detection threshold. No significant changes were observed in IFN-γ levels. The mucosal immune response was observed only 3 months after the PrEP administration. Conclusion. We provided a real-world experience model on the clinical efficacy of T/C PrEP in preventing severe COVID-19 during the Omicron wave through a comprehensive virological and immunological study. While waiting for the arrival of new monoclonal antibodies that can effectively neutralize the most recent variants, T/C PrEP remains the only viable strategy in the available armamentarium today to prevent COVID-19 complications in an extremely fragile population with suboptimal immune responses to COVID-19 vaccines.

Immunogenicity and reactogenicity of modified vaccinia Ankara pre-exposure vaccination against mpox according to previous smallpox vaccine exposure and HIV infection: prospective cohort study.

Background: Pre-exposure vaccination with MVA-BN has been widely used against mpox to contain the 2022 outbreak. Many countries have defined prioritized strategies, administering a single dose to those historically vaccinated for smallpox, to achieve quickly adequate coverage in front of low supplies. Using epidemiological models, real-life effectiveness was estimated at approximately 36%-86%, but no clinical trials were performed. Few data on MVA-BN immunogenicity are currently available, and there are no established correlates of protection. Immunological response in PLWH in the context of the 2022 outbreak was also poorly described. Methods: Blood samples were collected from participants eligible for pre-exposure MVA-BN vaccination before (T1) receiving a full course of vaccine (single-dose for vaccine-experienced or smallpox-primed and two-dose for smallpox vaccine-naïve or smallpox non-primed) and one month after the last dose (T2 and T3, respectively). MPXV-specific IgGs were measured by in-house immunofluorescence assay, using 1:20 as screening dilution, MPXV-specific nAbs by 50% plaque reduction neutralization test (PRNT50, starting dilution 1:10), and IFN-γ-producing specific T cells to MVA-BN vaccine, by ELISpot assay. Paired or unpaired t-test and Wilcoxon or Mann-Whitney test were used to analyse IgG and nAbs, and T-cell response, as appropriate. The probability of IgG and nAb response in vaccine-experienced vs. vaccine-naïve was estimated in participants not reactive at T1. The McNemar test was used to evaluate vaccination's effect on humoral response both overall and by smallpox vaccination history. In participants who were not reactive at T1, the proportion of becoming responders one month after full-cycle completion by exposure groups was compared by logistic regression and then analysed by HIV status strata (interaction test). The response was also examined in continuous, and the Average Treatment Effect (ATE) of the difference from baseline to schedule completion according to previous smallpox vaccination was estimated after weighting for HIV using a linear regression model. Self-reports of adverse effects following immunization (AEFIs) were prospectively collected after the first MVA-BN dose (T1). Systemic (S-AEFIs: fatigue, myalgia, headache, GI effects, chills) and local (L-AEFIs: redness, swelling, pain) AEFIs were graded as absent (grade 0), mild (1), moderate (2), or severe (3). The maximum level of severity for S-AEFIs and L-AEFIs ever experienced over the 30 days post-dose by vaccination exposure groups were analysed using a univariable multinomial logistic regression model and after adjusting for HIV status; for each of the symptoms, we also compared the mean duration by exposure group using an unpaired t-test. Findings: Among the 164 participants included, 90 (54.8%) were smallpox vaccine-experienced. Median age was 49 years (IQR 41-55). Among the 76 (46%) PLWH, 76% had a CD4 count >500 cells/µL. There was evidence that both the IgG and nAbs titers increased after administration of the MVA-BN vaccine. However, there was no evidence for a difference in the potential mean change in humoral response from baseline to the completion of a full cycle when comparing primed vs. non-primed participants. Similarly, there was no evidence for a difference in the seroconversion rate after full cycle vaccination in the subset of participants not reactive for nAbs at T1 (p = 1.00 by Fisher's exact test). In this same analysis and for the nAbs outcome, there was some evidence of negative effect modification by HIV (interaction p-value = 0.17) as primed people living with HIV (PLWH) showed a lower probability of seroconversion vs. non-primed, and the opposite was seen in PLWoH. When evaluating the response in continuous, we observed an increase in T-cell response after MVA-BN vaccination in both primed and non-primed. There was evidence for a larger increase when using the 2-dose vs. one-dose strategy with a mean difference of -2.01 log2 (p ≤ 0.0001), after controlling for HIV. No evidence for a difference in the risk of developing any AEFIs of any grade were observed by exposure group, except for the lower risk of grade 2 (moderate) fatigue, induration and local pain which was lower in primed vs. non-primed [OR 0.26 (0.08-0.92), p = 0.037; OR 0.30 (0.10-0.88), p = 0.029 and OR 0.19 (0.05-0.73), p = 0.015, respectively]. No evidence for a difference in symptom duration was also detected between the groups. Interpretation: The evaluation of the humoral and cellular response one month after the completion of the vaccination cycle suggested that MVA-BN is immunogenic and that the administration of a two-dose schedule is preferable regardless of the previous smallpox vaccination history, especially in PLWH, to maximize nAbs response. MVA-BN was safe as well tolerated, with grade 2 reactogenicity higher after the first administration in vaccine-naïve than in vaccine-experienced individuals, but with no evidence for a difference in the duration of these adverse effects. Further studies are needed to evaluate the long-term duration of immunity and to establish specific correlates of protection. Funding: The study was supported by the National Institute for Infectious Disease Lazzaro Spallanzani IRCCS "Advanced grant 5 × 1000, 2021" and by the Italian Ministry of Health "Ricerca Corrente Linea 2".

Long Term Assessment of Anti-SARS-CoV-2 Immunogenicity after mRNA Vaccine in Persons Living with HIV.

(1) Background: Waning of neutralizing and cell-mediated immune response after the primary vaccine cycle (PVC) and the first booster dose (BD) is of concern, especially for PLWH with a CD4 count ≤200 cells/mm3. (2) Methods: Neutralizing antibodies (nAbs) titers by microneutralization assay against WD614G/Omicron BA.1 and IFNγ production by ELISA assay were measured in samples of PLWH at four time points [2 and 4 months post-PVC (T1 and T2), 2 weeks and 5 months after the BD (T3 and T4)]. Participants were stratified by CD4 count after PVC (LCD4, ≤200/mm3; ICD4, 201-500/mm3, and HCD4, >500/mm3). Mixed models were used to compare mean responses over T1-T4 across CD4 groups. (3) Results: 314 PLWH on ART (LCD4 = 56; ICD4 = 120; HCD4 = 138) were enrolled. At T2, levels of nAbs were significantly lower in LCD4 vs. ICD4/HCD4 (p = 0.04). The BD was crucial for increasing nAbs titers above 1:40 at T3 and up to T4 for WD614G. A positive T cell response after PVC was observed in all groups, regardless of CD4 (p = 0.31). (4) Conclusions: Waning of nAbs after PVC was more important in LCD4 group. The BD managed to re-establish higher levels of nAbs against WD614G, which were retained for 5 months, but for shorter time for Omicron BA.1. The T cellular response in the LCD4 group was lower than that seen in participants with higher CD4 count, but, importantly, it remained above detectable levels over the entire study period.

Risk Awareness as a Key Determinant of Early Vaccine Uptake in the Mpox Vaccination Campaign in an Italian Region: A Cross-Sectional Analysis.

BACKGROUND: we aim to investigate attitudes toward vaccination by analyzing empirical factors associated with vaccine acceptance in the Lazio region mpox vaccination (MpoxVax) campaign in Italy. METHODS: all subjects who accessed MpoxVax and signed the informed consent were prospectively enrolled in the MPOX-VAC Study and were asked to fill out an anonymous survey. Two endpoints were selected: 'delayed acceptance' and 'early acceptance', defined as access for vaccination >60 and ≤30 days from the vaccination campaign starting (VCS), respectively. RESULTS: over the study period, 1717 individuals underwent vaccination: 129 (7%) > 60 [1588 (92.5%) ≤ 60] and 676 (60%) ≤ 30 days from VCS. A bisexual orientation, a lower education level and a worse perceived physical and mental health were associated with delayed access to vaccination. Being pre-exposure prophylaxis (PrEP) users and, marginally, HIV positive; having a high perceived risk for mpox infection; and reporting high-risk behaviors like the use of recreational drugs/chems, sex under the influence of drugs and/or alcohol and having a higher number of principal sexual partners, were associated with early access to vaccination. CONCLUSIONS: according to our data, risk awareness was a major determinant of early MpoxVax acceptance. Conversely, worse perceived health status and a low educational level were critical factors associated with delayed vaccination.