Explore the vast range of titles available.

Messenger RNA (mRNA) vaccines are being used to combat the spread of COVID-19 (refs. 1 – 3 ), but they still exhibit critical limitations caused by mRNA instability and degradation, which are major obstacles for the storage, distribution and efficacy of the vaccine products 4 . Increasing secondary structure lengthens mRNA half-life, which, together with optimal codons, improves protein expression 5 . Therefore, a principled mRNA design algorithm must optimize both structural stability and codon usage. However, owing to synonymous codons, the mRNA design space is prohibitively large—for example, there are around 2.4 × 10 632 candidate mRNA sequences for the SARS-CoV-2 spike protein. This poses insurmountable computational challenges. Here we provide a simple and unexpected solution using the classical concept of lattice parsing in computational linguistics, where finding the optimal mRNA sequence is analogous to identifying the most likely sentence among similar-sounding alternatives 6 . Our algorithm LinearDesign finds an optimal mRNA design for the spike protein in just 11 minutes, and can concurrently optimize stability and codon usage. LinearDesign substantially improves mRNA half-life and protein expression, and profoundly increases antibody titre by up to 128 times in mice compared to the codon-optimization benchmark on mRNA vaccines for COVID-19 and varicella-zoster virus. This result reveals the great potential of principled mRNA design and enables the exploration of previously unreachable but highly stable and efficient designs. Our work is a timely tool for vaccines and other mRNA-based medicines encoding therapeutic proteins such as monoclonal antibodies and anti-cancer drugs 7 , 8 . An algorithm based on concepts established in computational linguistics enables rapid principled design of mRNA vaccines optimizing both structural stability and codon usage, resulting in improved half-life, protein expression and immune responses.

Varicella-zoster virus (VZV) causes clinically significant illness during acute and recurrent infection accompanied by robust innate and acquired immune responses. Innate immune cells in skin and ganglion secrete type I interferon (IFN-I) and proinflammatory cytokines to control VZV. Varicella-zoster virus subverts pattern recognition receptor sensing to modulate antigen presentation and IFN-I production. During primary infection, VZV hijacks T cells to disseminate to the skin and establishes latency in ganglia. Durable T- and B-cell memory formed within a few weeks of infection is boosted by reactivation or re-exposure. Antigen-specific T cells are recruited and potentially retained in VZV-infected skin to counteract reactivation. In latently VZV-infected ganglia, however, virus-specific T cells have not been recovered, suggesting that local innate immune responses control VZV latency. Antibodies prevent primary VZV infection, whereas T cells are fundamental to resolving disease, limiting severity, and preventing reactivation. In this study, we review current knowledge on the interactions between VZV and the human immune system.

Background. Human immunodeficiency virus (HIV)-infected individuals are at increased risk of herpes zoster (HZ), even in the antiretroviral therapy (ART) era. Because concerns exist about the use of live-attenuated vaccines in immunocompromised individuals, a subunit vaccine may be an appropriate alternative. Methods. This phase 1/2, randomized, placebo-controlled study evaluated the immunogenicity and safety of an investigational HZ subunit vaccine (HZ/su). Three cohorts of HIV-infected adults aged ≥18 years were enrolled: 94 ART recipients with a CD4⁺ T-cell count of ≥200 cells/mm³, 14 ART recipients with a CD4⁺ T-cell count of 50-199 cells/mm³, and 15 ART-naive adults with a CD4⁺ T-cell count of ≥500 cells/mm³. Subjects received 3 doses of HZ/su (50 μg varicella-zoster virus glycoprotein E [gE] combined with AS01B adjuvant) or 3 doses of saline at months 0, 2, and 6. Results. One month after dose 3, serum anti-gE antibody concentrations and frequencies of gE-specific CD4⁺ T cells were higher following HZ/su vaccination than after receipt of saline (P<.0001). Median cell-mediated immune responses peaked after dose 2. Humoral and cell-mediated immune responses persisted until the end of the study (month 18). No vaccination-related serious adverse events were reported. No sustained impact on HIV load or CD4⁺ T-cell count was noted following vaccinations. Conclusions. HZ/su was immunogenic and had a clinically acceptable safety profile in HIV-infected adults. Clinical Trials Registration. NCT01165203

•After 10 years of post-marketing use, safety of zoster vaccine live remains favorable.•93% of reports of adverse experiences were non-serious.•Injection-site reactions were the most commonly reported adverse experience.•Vaccine-strain varicella-zoster virus was identified by PCR in 14 specimens.•Disseminated herpes zoster was reported very rarely. Zoster vaccine is a single dose live, attenuated vaccine (ZVL) indicated for individuals ≥50 years-old for the prevention of herpes zoster (HZ). Safety data from clinical trials and post-licensure studies provided reassurance that ZVL is generally safe and well tolerated. The objective of this review was to provide worldwide post-marketing safety information following 10 years of use and >34 million doses distributed. All post-marketing adverse experience (AE) reports received worldwide between 02-May-2006 and 01-May-2016 from healthcare professionals following vaccination with ZVL and submitted to the MSD AE global safety database, were analyzed. A total of 23,556 AE reports, 93% non-serious, were reported. Local injection site reactions (ISRs), with a median time-to-onset of 2 days, were the most frequently reported AEs followed by HZ. The majority of HZ reports were reported within 2 weeks of vaccination and considered, based on time-to-onset, pathogenesis of HZ, and data from clinical trials, to be caused by wild-type varicella-zoster virus (VZV). HZ confirmed by PCR analysis to be VZV Oka/Merck vaccine-strain was identified in an immunocompetent individual 8 months postvaccination and in 4 immunocompromised individuals. Disseminated HZ was reported very rarely (<1%) with 38% occurring in immunocompromised individuals. All reports of disseminated HZ confirmed by PCR as VZV Oka/Merck vaccine-strain were in individuals with immunosuppressive conditions and/or therapy at the time of vaccination. The safety profile of ZVL, following 10 years of post-marketing use, was favorable and consistent with that observed in clinical trials and post-licensure studies.

The adjuvanted varicella-zoster virus (VZV) glycoprotein E (gE) subunit herpes zoster vaccine (HZ/su) confers higher protection against HZ than the live attenuated zoster vaccine (ZV). To understand the immunologic basis for the different efficacies of the vaccines, we compared immune responses to the vaccines in adults 50 to 85 years old. gE-specific T cells were very low/undetectable before vaccination when analyzed by FluoroSpot and flow cytometry. Both ZV and HZ/su increased gE-specific responses, but at peak memory response (PMR) after vaccination (30 days after ZV or after the second dose of HZ/su), gE-specific CD4+ and CD8+ T cell responses were 10-fold or more higher in HZ/su compared with ZV recipients. Comparing the vaccines, T cell memory responses, including gE-IL-2+ and VZV-IL-2+ spot-forming cells (SFCs), were higher in HZ/su recipients and cytotoxic and effector responses were lower. At 1 year after vaccination, all gE-Th1 and VZV-IL-2+ SFCs remained higher in HZ/su compared with ZV recipients. Mediation analyses showed that IL-2+ PMR were necessary for the persistence of Th1 responses to either vaccine and VZV-IL-2+ PMR explained 73% of the total effect of HZ/su on persistence. This emphasizes the biological importance of the memory responses, which were clearly superior in HZ/su compared with ZV participants.

People living with HIV (PLWH) have a higher risk of herpes zoster (HZ) reactivation and postherpetic neuralgia (PHN) compared to general population. Our study aims to evaluate prevalence of HZ reactivation and PHN after vaccination with recombinant vaccine (RZV) in a population living with HIV, and to identify risk factors associated with recurrence. We conducted an observational study, enrolling all PLWH ≥18 years old vaccinated with RZV from January 2022 to December 2023. A questionnaire was proposed to the subjects at least 6 months after vaccination, inquiring about previous history of HZ and PHN, and recurrence after vaccination. We collected demographic characteristics, comorbidities, viro-immunological status, and medications. We performed a descriptive analysis and univariate logistic regressions to investigate risk factors associated with HZ reactivation and PHN persistence. We included 223 subjects. We estimated the prevalence of events among 145 subjects: we recorded 54 subjects with pre-vaccination HZ (prevalence 37.24 % [IC 95 %: 29.36% – 45.65 %]) and 13 with post-vaccination HZ (prevalence 8.97 % [IC 95 %: 4.86 % - 14.84 %]). The prevalence of pre-vaccination PHN was 19.23 % [IC 95 %: 11.18 % - 29.73 %], with mean NRS 6.33 [IC 95 %: 4.9–7.76]; no case of PHN was recorded after vaccination. Evaluating risk factors related to post-vaccination HZ, we didn't find any association with viro-immunological status, clinical history of HIV infection, or concomitant medications. We correlate HZ and age (OR 1.06, CI 95 % 1.01–1.13, p-value 0.031), haematological (OR 9.60, CI 95 % 1.70–49.9, p-value 0.007), oncological (OR 5.36, CI 95 % 1.04–22.8, p-value 0.028), and hepatic comorbidities (OR 3.67, CI 95 % 1.10–12.0, p-value 0.030). This is the first real-world study that highlights the excellent clinical response to RZV, with a low prevalence of HZ reactivation and complete resolution of PHN after the vaccination. Moreover, we identified clinical conditions promoting the recurrence HZ after vaccination.

Reactivation of the varicella zoster virus (VZV) increases during aging. Although the effects of VZV reactivation are observed in the skin (shingles), the number and functional capacity of cutaneous VZV-specific T cells have not been investigated. The numbers of circulating IFN-γ-secreting VZV-specific CD4+ T cells are significantly decreased in old subjects. However, other measures of VZV-specific CD4+ T cells, including proliferative capacity to VZV antigen stimulation and identification of VZV-specific CD4+ T cells with an major histocompatibility complex class II tetramer (epitope of IE-63 protein), were similar in both age groups. The majority of T cells in the skin of both age groups expressed CD69, a characteristic of skin-resident T cells. VZV-specific CD4+ T cells were significantly increased in the skin compared with the blood in young and old subjects, and their function was similar in both age groups. In contrast, the number of Foxp3+ regulatory T cells and expression of the inhibitory receptor programmed cell death -1 PD-1 on CD4+ T cells were significantly increased in the skin of older humans. Therefore, VZV-specific CD4+ T cells in the skin of older individuals are functionally competent. However, their activity may be restricted by multiple inhibitory influences in situ.

When the adjuvanted HZ subunit vaccine candidate was coadministered with a quadrivalent seasonal influenza vaccine, no interference in the immune responses were observed, and no safety concerns were identified. Abstract Background The immunogenicity and safety of an adjuvanted herpes zoster subunit (HZ/su) vaccine when coadministered with a quadrivalent seasonal inactivated influenza vaccine (IIV4) was investigated in a phase 3, open-label, randomized clinical trial in adults aged ≥50 years. Methods Subjects were randomized 1:1 to receive either HZ/su (varicella zoster virus glycoprotein E; AS01B Adjuvant System) and IIV4 at day 0 followed by a second HZ/su dose at month 2 (coadministration group), or IIV4 at month 0 and HZ/su at months 2 and 4 (control group). The primary objectives were the HZ/su vaccine response rate in the coadministration group and the noninferiority of the antibody responses to HZ/su and IIV4 in the coadministration compared with the control group. Safety information was collected throughout the duration of the study. Results A total of 413 subjects were vaccinated in the coadministration group and 415 in the control group. The HZ/su vaccine response rate in the coadministration group was 95.8% (95% confidence interval, 93.3%–97.6%) and the anti–glycoprotein E GMCControl/Coadmin ratio was 1.08 (.97–1.20). The primary noninferiority objectives were met. No safety concerns were observed. Conclusions No interference in the immune responses to either vaccine was observed when the vaccines were coadministered, and no safety concerns were identified. Clinical Trials Registration NCT01954251.

Varicella-zoster virus (VZV) and herpes simplex virus (HSV) are prevalent neurotropic herpesviruses that cause various nervous system diseases. Similar to other enveloped viruses, membrane fusion is an essential process for viral entry. Therefore, identification of host molecules that mediate membrane fusion is important to understand the mechanism of viral infection. Here, we demonstrate that myelin-associated glycoprotein (MAG), mainly distributed in neural tissues, associates with VZV glycoprotein B (gB) and promotes cell-cell fusion when coexpressed with VZV gB and gH/gL. VZV preferentially infected MAG-transfected oligodendroglial cells. MAG also associated with HSV-1 gB and enhanced HSV-1 infection of promyelocytes. These findings suggested that MAG is involved in VZV and HSV infection of neural tissues.

Mucosal-associated invariant T (MAIT) cells are unconventional T cells that respond to riboflavin biosynthesis and cytokines through TCR-dependent and -independent pathways, respectively. MAIT cell activation plays an immunoprotective role against several pathogens, however the functional capacity of MAIT cells following direct infection or exposure to infectious agents remains poorly defined. We investigated the impact of Varicella Zoster Virus (VZV) on blood-derived MAIT cells and report virus-mediated impairment of activation, cytokine production, and altered transcription factor expression by VZV infected (antigen+) and VZV exposed (antigen-) MAIT cells in response to TCR-dependent and -independent stimulation. Furthermore, we reveal that suppression of VZV exposed (antigen-) MAIT cells is not mediated by a soluble factor from neighbouring VZV infected (antigen+) MAIT cells. Finally, we demonstrate that VZV impairs the cytolytic potential of MAIT cells in response to riboflavin synthesising bacteria. In summary, we report a virus-mediated immune-evasion strategy that disarms MAIT cell responses.