Search Results (139)

Background: Immunization is a highly effective intervention for controlling over 20 life-threatening infectious diseases, significantly reducing both morbidity and mortality rates. One notable achievement in vaccination efforts was the global eradication of smallpox, which the World Health Assembly declared on 8 May 1980. Additionally, there has been a remarkable 99.9% reduction in wild poliovirus cases since 1988, decreasing from more than 350,000 cases that year to just 30 cases in 2022. Objectives: The objective of this review was to assess the effects of various interventions designed to increase vaccination uptake among adults. Search Methods: A thorough search was conducted in the CENTRAL, Embase Ovid, Medline Ovid, PubMed, Web of Science, and Global Index Medicus databases for primary studies. This search was conducted in August 2021 and updated in November 2024. Selection Criteria: Randomized trials were eligible for inclusion in this review, regardless of publication status or language. Data Analysis: Two authors independently screened the search outputs to select potentially eligible studies. Risk ratios (RR) with 95% confidence intervals (CI) were calculated for each randomized controlled trial (RCT). A meta-analysis was conducted using a random-effects model, and the quality of the evidence was assessed using the GRADE approach. Main Results: A total of 35 randomized controlled trials met the inclusion criteria and were included in this review, with the majority conducted in the United States. The interventions targeted adults aged 18 and older who were eligible for vaccination, involving a total of 403,709 participants. The overall pooled results for interventions aimed at increasing influenza vaccination showed a risk ratio of 1.41 (95% CI: 1.15, 1.73). Most studies focused on influenza vaccination (18 studies), while the remaining studies examined various other vaccines, including those for hepatitis A, COVID-19, hepatitis B, pneumococcal disease, tetanus, diphtheria, pertussis (Tdap), herpes zoster, and human papillomavirus (HPV). The results indicate that letter reminders were slightly effective in increasing influenza vaccination uptake compared to the control group (RR: 1.75, 95% CI: 0.97, 1.16; 6 studies; 161,495 participants; low-certainty evidence). Additionally, participants who received education interventions showed increased levels of influenza vaccination uptake compared to those in the control group (RR: 1.88, 95% CI: 0.61, 5.76; 3 studies; 1318 participants; low-certainty evidence). Furthermore, tracking and outreach interventions also led to an increase in influenza vaccination uptake (RR: 1.87, 95% CI: 0.78, 4.46; 2 studies; 33,752 participants; low-certainty evidence). Conclusions: Letter reminders and educational interventions targeted at recipients are effective in increasing vaccination uptake compared to control groups. Full article

The varicella-zoster virus is a human herpesvirus that causes varicella as the primary infection and HZ as the reactivation of a latent infection. Ten to twenty percent of cases of herpes zoster ophthalmicus (HZO) involve the ophthalmic branch of the fifth cranial nerve. Any area of the eye may be affected by the condition. HZ has a lifetime risk of more than 30%. Complications from herpes zoster can significantly lower quality of life. The goal of HZ vaccinations is to stop HZ activation and PHN formation. Despite the uncommon possibility of side effects such as eye problems, the majority of vaccines on the market now are safe. The purpose of this review is to discuss VZV infection and analyze and summarize the ocular complications following VZV vaccination. Full article

Background: Older adults living in aged care are at risk of poor health outcomes due to influenza, pneumococcal disease, and herpes zoster infections. Despite these conditions being vaccine-preventable, little is known about vaccine uptake rates in the residential elderly care setting in Australia. Methods: This was a retrospective cohort study examining the medical records of residents of 31 aged care homes in Australia (n = 1108). Data were extracted from medical records for the period March 2023 to September 2023. The proportion of residents vaccinated against influenza, pneumococcal disease, and herpes zoster was calculated. Univariate and multivariate logistic regressions were used to identify possible demographic and other characteristics associated with the vaccination uptake. Results: This study included 1108 residents. Two-thirds (68%) were female, and the median age was 87 years. All residents had one or more comorbidities. Most (92.6%) had received an influenza vaccine within the prior two years, but only 38.3% had received a pneumococcal vaccine, and 16.8% had received herpes zoster vaccination. In all models, receipt of the other vaccines was a significant predictor for vaccine administration. The other factor associated with influenza vaccination was non-consumption of alcohol and younger age for herpes zoster vaccination. Conclusions: While there is a high uptake of influenza vaccines, there is a low uptake of both pneumococcal and herpes zoster vaccines in residents of aged care facilities. Further research into the barriers and enablers of vaccine uptake should be undertaken, with the goal of increasing the vaccination uptake in this vulnerable population. Full article

Background: Immunocompromised patients are at risk of severe varicella zoster virus (VZV) infection and reactivation. In VZV seronegative immunocompromised persons, live-attenuated VZV vaccination is contraindicated, thus the recombinant herpes zoster vaccine (rHZV) remains a safe alternative, although an off-label application. Yet, data on the induction of a VZV-specific immune response in immunocompromised individuals with VZV-specific IgG below the assay’s cut-off are only available for patients after solid-organ transplantation (SOT). Methods: We retrospectively analyzed the induction of VZV-specific IgG antibody levels after vaccination with rHZV in immunocompromised patients who previously tested anti-VZV-IgG negative between March 2018 and January 2024. Results: Of 952 vaccinees screened that received 2 or 3 doses rHZV, depending on the underlying disease, 33 patients (median age 53.0; 51.5% female) with either hematopoietic stem cell transplantation (82%) or high-grade immunosuppressive treatment (18%) fulfilled the inclusion criteria. Upon rHZV vaccination, 88% (29/33) individuals mounted a significant antibody response exceeding the assay’s cut-off level for seropositivity (p < 0.0001). We detected higher geometric mean antibody concentrations after three compared to two doses. However, 12% remained below the assay’s cut-off level and were therefore considered non-responsive. Conclusions: The rHZV is immunogenic in VZV-seronegative immunocompromised individuals and therefore presents a valid option to induce seroconversion. However, antibody testing in high-risk groups should be considered to identify humoral non- and low responders. Full article

Varicella-zoster virus (VZV) poses significant public health challenges as the etiological agent of varicella (chickenpox) and herpes zoster (HZ), given its high transmissibility and potential for severe complications. The introduction of VZV vaccines—particularly the vOka-based live attenuated and glycoprotein gE-based recombinant subunit vaccines—has substantially reduced the global incidence of these diseases. However, live attenuated vaccines raise concerns regarding safety and immunogenicity, especially in immunocompromised populations, while recombinant subunit vaccines, such as Shingrix, exhibit high efficacy but are associated with side effects and adjuvant limitations. Recent advancements in vaccine technology, including mRNA vaccines, viral vector vaccines, and virus-like particle (VLP) vaccines, offer promising alternatives with improved safety profiles and durable immunity. This review synthesizes current knowledge on VZV vaccine mechanisms, clinical applications, and immunization strategies, while also examining future directions in vaccine development. The findings underscore the pivotal role of VZV vaccines in disease prevention and highlight the need for continued research to enhance their public health impact. Full article

Aim: To investigate the knowledge of and attitudes towards herpes zoster (HZ) and its vaccination, as well as the vaccination status of Chinese patients with rheumatic disease. Method: A face-to-face questionnaire survey was conducted among patients visiting the Department of Rheumatology and Clinical Immunology, Peking University First Hospital from 1 March to 30 April 2024. Information on HZ infection and vaccination status was recorded. The questionnaire assessed their knowledge of HZ and the HZ vaccine with nine questions, scoring one point for each correct answer, resulting in a total score ranging from zero to nine. Attitudes toward HZ and vaccines were measured by a five-point Likert scale, with scores ranging from one (“strongly disagree”) to five (“strongly agree”). Factors associated with knowledge and attitude scores were analyzed using an ordinal logistic regression. Results: A total of 1036 patients completed the questionnaire, with a mean age of 47.1 years, and 79.3% were females. The three most prevalent diseases were systemic lupus erythematosus (32.4%), rheumatoid arthritis (26.3%) and Sjögren’s syndrome (9.9%). A total of 243 patients (23.5%) reported a history of HZ or current HZ infection. Only 2.0% of the patients had been vaccinated, while 51.0% expressed willingness to be vaccinated in the future. The median knowledge score was four (2, 5) (ranging from zero to nine), and the median attitude score was 19 (17, 20) (ranging from 5 to 25). Factors associated with higher knowledge scores included being female (β = 0.448, p = 0.001), having a higher educational level (β = 0.355, p < 0.001), having a higher monthly income (β = 0.191, p = 0.008) and having comorbidities (β = 0.275, p = 0.023). Factors associated with higher attitude scores included being female (β = 0.279, p = 0.035), having a higher monthly income (β = 0.196, p = 0.037) and possessing a higher education level (β = 0.310, p = 0.045). Conclusions: Patients with rheumatic disease in China exhibit a low level of cognition regarding HZ as well as its vaccine, and the vaccination rate is very low. To improve the understanding and prevention awareness of HZ, health education should be intensified, particularly targeting males, those with lower levels of education and lower-income patients. Full article

Introduction: Herpes zoster (HZ), or shingles, is a vaccine-preventable disease with two approved vaccines: the live-attenuated vaccine (LZV) and the adjuvanted recombinant zoster vaccine (RZV). Evidence on the immunogenicity and adverse events (AEs) following co-administration with other vaccines in adults is limited. This systematic review and meta-analysis aims to evaluate the immunogenicity and safety of HZ vaccines when co-administered with other vaccines. Methods: We followed PRISMA 2020 guidelines and systematically searched multiple databases (January 1950 to February 2024) for studies on HZ vaccination with concomitant vaccines in adults (≥18 years). Observational studies, randomized controlled trials (RCTs), and non-randomized controlled trials were included, excluding reviews, case series, case reports, editorials, and non-English publications. Risk of bias was assessed using Cochrane tools (RoB 2 and ROBINS-I). A meta-analysis compared geometric mean concentration (GMC) ratios and vaccine response rates (VRRs) for RZV, applying the Hartung–Knapp adjustment. For LZV, meta-analysis was not feasible, and results were described narratively. AEs were analyzed using risk ratios and presented in forest plots. Results: Out of 369 search hits, ten RCTs were included. In six RCTs, RZV was co-administered with influenza, COVID-19, pneumococcal vaccines (PCV13, PPSV23), or Tdap. The pooled GMC mean difference was −0.04 (95% CI: −0.10 to 0.02, p = 0.19), and the pooled VRR was 1.00 (95% CI: 0.99 to 1.01, p = 0.59). Local and systemic AEs showed pooled relative risks of 0.99 (95% CI: 0.95 to 1.03, p = 0.73) and 1.01 (95% CI: 0.91 to 1.11, p = 0.90), respectively. LZV co-administration was investigated in four RCTs and was safe; however, co-administration with PPSV23 resulted in reduced immunogenicity. Conclusions: The co-administration of RZV with other vaccines was safe and immunogenic. However, limited evidence suggests that co-administration of LZV with PPSV23 reduced the immunogenicity of LZV through an unknown mechanism. Still, RZV co-administration could enhance vaccine uptake in vulnerable populations. Full article

Understanding the contribution of human herpesviruses to the aetiology of neurodegenerative diseases is an emerging field of interest. The association of Epstein–Barr virus with multiple sclerosis is the most researched example; however, the definitive proof of causation is still lacking. Alzheimer’s disease (AD) is the most common form of dementia and typically manifests in individuals aged over 65 years; however, it also occurs in a small number of individuals aged less than 65 years. A combination of environmental, genetic, and lifestyle factors is believed to contribute to the development of AD. There have been several reports describing potential associations of infections or reactivations of human alphaherpesviruses with AD. A particular characteristic of human alphaherpesviruses (herpes simplex viruses 1 and 2, varicella zoster virus) is that they are neurotropic and that lifelong infection (latency) is established mainly in the dorsal root and trigeminal ganglia. There have also been reports that suppression of alphaherpesvirus infections through either vaccination or the application of antiviral treatments may be protective against the development of AD. Zoster vaccines and acyclovir may prove to be effective interventions for preventing or limiting the progression of AD. This is particularly relevant as there are currently no available cheap and effective treatments for AD. In this review, the basic virology of human alphaherpesviruses is described followed by their epidemiology and associations with AD. Finally, the prevention and treatment of human alphaherpesviruses are considered in the context of potential applications for the prevention of AD. Full article

Background: Alzheimer’s Disease (AD) represents a significant public health challenge with a rising global burden. Emerging evidence suggests a potential link between herpes zoster (HZ) and an increased risk of AD. These findings indicate that HZ may contribute to neuroinflammation and other pathophysiological processes associated with AD, pointing out the potential role of the virus infection in the initiation and/or progression of AD pathology. Objective: This systematic review evaluates the relationships between HZ and the risk of AD, highlighting the potential neuroprotective role of HZ vaccination and antiherpetic drug (AHD) use. Methods: Adhering to the (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) PRISMA guidelines, a comprehensive search of databases (e.g., PubMed) until October 2024 was conducted. Observational studies reporting risk estimates were included. Extracted data were synthesized and analyzed narratively due to study heterogeneity. Results: Eleven studies (out of two hundred) met the inclusion criteria, offering preliminary insights that could form a foundation for further investigation. Reports on HZ showed mixed outcomes, with some studies suggesting a potential increased risk of AD, while others showed no clear correlation. Interestingly, HZ vaccination led to a potential preventive role in reducing the risk of AD, with risk estimates ranging from 0.57 to 0.99. Additionally, the use of AHDs was linked to a reduced risk of AD, with risk estimates ranging from 0.65 to 0.96. Conclusions: Published findings suggest that HZ vaccination and AHD use could represent potential interventions to reduce the risk of AD; however, further research is necessary to validate these findings and better understand the underlying protective mechanisms. Full article

Background: Secondary immunodeficiencies in allo-HSCT (allogeneic hematopoietic stem cell transplantation) recipients increase the risk of viral reactivation, making vaccinations a vital issue. There is a paucity of data on the use of recombinant vaccine against herpes zoster (RZV) after allo-HSCT. Methods: This analysis included 149 recipients of allo-HSCT, transplanted in 2012–2022, mainly due to hematological malignancies (>95%). RZV was used from 2021 to 2023 according to the current recommendations of ACIP. The ELISA method was used to assess the VZV IgG antibody titers. Results: VZV reactivation was diagnosed in 49 out of 149 (33%) patients before vaccination, including 5 (3%) patients with reactivation within the first year after transplantation and the remaining 44 (30%) within the subsequent three years. At that time, the majority of patients were not receiving acyclovir prophylaxis. The most common clinical manifestation of reactivation was involvement of intercostal nerves, diagnosed in 40 (81%) patients. Twenty-one recipients (median age: 41) received two doses of RZV (at a median time of 34 months after transplantation, range 12–84 months), the majority of them at an interval of 1 month. The serological post-vaccination response was confirmed in 12 recipients, with a ratio of 2.38–8.3 (median 5.095). The median number of total CD3+CD4+cells in vaccinated patients was 451/μL. Despite vaccination, four patients (19%, three with confirmed serological response) developed herpes zoster. Conclusions: Herpes zoster occurred mainly in the late period after allo-HSCT after completion of acyclovir prophylaxis in over 30% of recipients. The preliminary results indicate that RZV vaccination after allo-HSCT was safe and more than 80% effective at preventing HZ, but some vaccinated individuals did experience HZ. Full article

Background: The varicella–zoster virus (VZV) is a human herpesvirus that primarily causes varicella (chickenpox) as an initial infection, characterized by distinctive skin lesions. It can later reactivate, leading to herpes zoster (shingles). Once reactivated, VZV infection may result in serious complications, the most common being postherpetic neuralgia. Fortunately, vaccination can prevent this condition. Objectives: In this study, we provide a comprehensive analysis of zoster vaccines, including clinical trials, safety profiles, and reimbursement guidelines across various countries. Results: Our findings confirm the vaccine’s effectiveness and safety across diverse populations, aligning with previous clinical trials and real-world data, and summarize global vaccination guidelines. Full article

Background/Objective: Historically, immunization programs have focused on infants, children, and women of reproductive age. COVID-19 vaccination prompted countries to vaccinate adults. The objective of this manuscript is to provide a global overview of adult immunization policies post COVID-19 pandemic. Methods: We summarized WHO Strategic Advisory Group of Experts on Immunization (SAGE) recommendations by adult group and analyzed the data reported in 2024 (2023) by WHO Member States (MS) via the WHO/UNICEF electronic Joint Reporting Form on Immunization (eJRF) on national immunization schedules, and from other sources by WHO region and income group. Results: WHO policy recommendations exist for most of the licensed vaccines targeting adults; however, the inclusion in national immunization schedules is higher in high-income (HICs) and middle-income (MICs) countries. For pregnant women, 90% of MS reported vaccination against COVID-19 (65% in low-income countries [LICs]), 63% against tetanus-containing vaccines (73% in LICs), 57% against influenza (4% in LICs), and 21% against pertussis-containing vaccines (all MICs and HICs). For health workers, 91% against COVID-19 (92% in LICs), 59% against influenza (4% in LICs), and 25% against hepatitis B (10% in LICs). For adults with chronic diseases, COVID-19 vaccination data were not available, 58% against influenza, and 23% against pneumococcal disease. For older adults, more than 90% of MS across all income groups reported COVID-19 vaccination, 59% against influenza (8% of LICs versus 89% of HICs), 17% against pneumococcal, and 7% against herpes zoster (HZ). Conclusion: The disparities in adult immunization policies across income groups highlight the need to improve access and strengthen vaccination efforts. A life course approach is essential to maximize the full potential of immunization across all ages. Full article

Background/Objectives: An overwhelming burden to clinics, herpes zoster (HZ), or shingles, is a painful disease that occurs frequently among aged individuals with a varicella-zoster virus (VZV) infection history. The cause of shingles is the reactivation of dormant VZV in the dorsal root ganglia/cranial nerves of the human body. Patients with HZ experience sharp, intense, electric shock-like pain, which makes their health-related quality of life (HRQoL) extremely low. Methods: Various mRNA constructs were designed based on intracellular organelle-targeting strategies and AI algorithm-guided high-throughput automation platform screening and were then synthesized by in vitro transcription and encapsulated with four-component lipid nanoparticles (LNPs). Immunogenicity was evaluated on a naïve mouse model, long-term mouse model, and VZV-primed mouse model. Safety was evaluated by a modified “nestlet shredding” method for potential adverse effects induced by vaccines. Comparison between muscular and intradermal administrations was conducted using different inoculated approaches as well. Results: The best vaccine candidate, CVG206, showed robust humoral and cellular immune responses, durable immune protection, and the fewest adverse effects. The CVG206 administered intradermally revealed at least threefold higher humoral and cellular immune responses compared to intramuscular vaccination. The manufactured and lyophilized patch of CVG206 demonstrated good thermal stability at 2–8 °C during 9 months of storage. Conclusions: The lyophilized mRNA vaccine CVG206 possesses remarkable immunogenicity, long-term protection, safety, and thermal stability, and its effectiveness could even be further improved by intradermal administration, revealing that CVG206 is a promising vaccine candidate for HZ in future clinical studies. Full article

Background: Herpes zoster (HZ) is a painful neurocutaneous disease caused by the varicella-zoster virus. The recombinant zoster vaccine (RZV) is becoming increasingly incorporated into national vaccination schedules. We aimed to evaluate RZV from a global public health policy perspective. Methods: We performed a rapid review of studies evaluating the immunogenicity, efficacy, and effectiveness of RZV for protection against HZ and associated complications. We searched PubMed for English-language studies published between 7 August 2012 and 30 September 2023. Included studies reported vaccine efficacy or effectiveness against HZ and HZ-associated complications. Immunogenicity studies were included if they contributed to the understanding of RZV protection over time and/or co-administration with other vaccines. HZ outcomes were stratified by socio-demographic and clinical variables. Results: From 405 identified publications, 33 were eligible for the study. Most studies were conducted in the US (N = 12), across North America (N = 10), and Europe (N = 5), or across multiple locations across North America, Latin America, and Asia–Australia (N = 6). Vaccine efficacy against HZ in immunocompetent populations ranged between 90% and 97%, while effectiveness ranged between 71% and 86%. Protection stayed above 70% for at least 10 years, with no significant differences by age or ethnicity. Conclusions: RZV is effective in reducing the risk of HZ and its associated complications. Protection is long-lasting and the vaccine is suitable for older and immunocompromised populations. However, the decision to incorporate the vaccine into national policies depends on additional factors (e.g., cost-effectiveness), which may be difficult to characterize without an understanding of the global disease burden. Full article

Adverse events following immunizations (AEFIs) with recombinant zoster vaccine (RZV) are underexplored in fragile populations. This study aims to assess incidence, duration, and characteristics of AEFIs, focusing on the impact of sex, age, and prior Herpes Zoster (HZ) infection in a frail population, including solid organ transplant recipients. We conducted an observational study on patients receiving RZV, and AEFIs were classified as local or systemic and analyzed for incidence, duration, and patterns across groups. We showed that females had a higher incidence of AEFIs (p = 0.02), both local and systemic symptoms, such as swelling +/− redness at the site of injection and fatigue, after the first and second doses. Younger adults experienced more systemic reactions, while older adults reported more local events (e.g., redness and swelling, p = 0.01). Moreover, patients with previous HZ infection exhibited a higher incidence of AEFIs after the second dose (68% vs. 38%, p = 0.001). In conclusion, sex, age, and clinical history significantly influenced AEFI incidence and manifestations. Therefore, it is important to personalize vaccination strategies in frail populations, by tailored administration and monitoring plans, especially in females and individuals with prior HZ infection, to improve vaccine safety and patient outcomes. Full article