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Vaccine Mar 2021Varicella zoster virus (VZV) and its re-emergence as herpes zoster (HZ) is associated with significant morbidity and mortality. While studies show that VZV vaccination... (Review)
Review
BACKGROUND
Varicella zoster virus (VZV) and its re-emergence as herpes zoster (HZ) is associated with significant morbidity and mortality. While studies show that VZV vaccination is effective in reducing VZV incidence, many decision makers have not added VZV to their vaccination schedule, largely due to uncertainty surrounding the effect of VZV vaccination on HZ incidence (exogenous boosting, EB), and the cost-effectiveness (CE) of vaccination.
METHODS
A systematic review was conducted to identify the current published evidence of CE of VZV vaccination strategies where both VZV and HZ incidence were modelled.
RESULTS
Six studies (one published in 2003 and five between 2010 and 2019), were identified with all conducting cost-utility analysis using a dynamic transmission modelling approach and assuming EB. All predicted that mass infant VZV vaccination would rapidly reduce VZV incidence, but HZ incidence would increase. Compared with no-vaccination, the CE of VZV vaccination strategies ranged from higher costs and poorer outcomes (dominated), towards CE (incremental cost-effectiveness ratios of between $7,000 to $61,000 USD), or lower cost and better outcomes (dominant). However, without EB, HZ incidence immediately dropped below pre-vaccination levels making VZV vaccination quickly CE and/or dominant to a no vaccination strategy.
CONCLUSIONS
Current models are sensitive to assumptions of EB suggesting that future studies consider an agent-based modelling approach to address the individual nature of variables that determine the infectiousness of VZV.
Topics: Chickenpox; Chickenpox Vaccine; Cost-Benefit Analysis; Herpes Zoster; Herpesvirus 3, Human; Humans; Infant; Vaccination
PubMed: 33551300
DOI: 10.1016/j.vaccine.2021.01.061 -
Vaccine Jan 2024In countries where varicella vaccination is not on the routine childhood immunisation schedule, such as those in the United Kingdom (UK), chickenpox is an almost... (Review)
Review
BACKGROUND
In countries where varicella vaccination is not on the routine childhood immunisation schedule, such as those in the United Kingdom (UK), chickenpox is an almost universal disease of childhood. Chickenpox can cause serious complications, particularly in infants, pregnant women, and the immunocompromised. In November 2023 the varicella vaccine was recommended for inclusion in the UK routine childhood immunisation schedule. Successful rollout of the vaccine may be hindered by parental concerns about vaccine safety and efficacy, and perceptions of chickenpox as a mild illness.
OBJECTIVE
To examine parental perceptions of chickenpox and varicella vaccination, which may be crucial to effective vaccination campaigns.
DESIGN
Qualitative systematic review and thematic analysis.
METHODS
Six electronic databases were systematically searched for studies published between 2016 and 2023: CINAHL, EMBASE, MEDLINE, PsycInfo, PubMed, and Web of Science. The included studies were appraised against the Critical Appraisal Skills Program checklist for qualitative studies. Thematic analysis was used to analyse qualitative data, through the development of themes.
RESULTS
22 articles were included in this review, and five themes identified: perceptions that chickenpox is a mild illness, that parents have concerns about varicella vaccine efficacy and safety, a notion of natural immunity as superior, social determinants of health influence vaccine decision making, and vaccination is overwhelming perceived as a parental decision.
CONCLUSIONS
Whilst some parents displayed an acceptance and willingness to vaccinate against chickenpox, many expressed concerns, and perceived chickenpox as a routine unworrying childhood illness. Analysis demonstrated a knowledge gap in understanding UK parental opinions regarding chickenpox and varicella vaccination, highlighting the need for research in this area, particularly given ongoing reconsideration for inclusion in the UK vaccination schedule.
REGISTRATION
The review was registered on PROSPERO, registration ID CRD42021236120.
Topics: Pregnancy; Infant; Humans; Female; Chickenpox Vaccine; Chickenpox; Herpesvirus 3, Human; Parents; Vaccination; Vaccines, Attenuated
PubMed: 38129287
DOI: 10.1016/j.vaccine.2023.12.045 -
Human Vaccines & Immunotherapeutics Jun 2021We conducted a systematic review to characterize the incidence rate of herpes zoster (HZ) in the general population, specifically in individuals ≥50 years of age. A...
We conducted a systematic review to characterize the incidence rate of herpes zoster (HZ) in the general population, specifically in individuals ≥50 years of age. A total of 69 publications were included in the review. We found a cumulative incidence of HZ ranging from 2.9-19.5 cases per 1,000 population and an incidence rate of HZ ranging from 5.23-10.9 cases per 1,000 person-years. The cumulative incidence (3.22-11.2 versus 2.44-8.0 cases per 1,000 population) and incidence rates (6.05-12.8 versus 4.30-8.5 cases per 1,000 person-years) were higher in females than males. Studies revealed a trend of increasing incidence of HZ with increasing age and over time. Variations in incidence estimates can be attributed to the various study designs, case ascertainments, age distributions of the population and year of the study. HZ is associated with a substantial disease burden and is expected to increase due to population aging.
Topics: Age Distribution; Cost of Illness; Female; Herpes Zoster; Herpes Zoster Vaccine; Herpesvirus 3, Human; Humans; Incidence; Male
PubMed: 33651654
DOI: 10.1080/21645515.2020.1847582 -
Neurological Sciences : Official... Jan 2024The relationship between varicella zoster virus (VZV) infection and the risk of dementia has not been previously studied specifically. Therefore, this study sought to... (Meta-Analysis)
Meta-Analysis
PURPOSE
The relationship between varicella zoster virus (VZV) infection and the risk of dementia has not been previously studied specifically. Therefore, this study sought to determine the relationship between studying VZV infection and dementia occurring in the general population by conducting an extensive meta-analysis of published cases.
METHOD
A systematic literature search was conducted in seven online databases by October 31, 2022. Heterogeneity was tested by the I index. Pooled HR and 95% CI were used to estimate the effect of VZV infection on dementia. Sensitivity analyses and publication bias were also performed.
RESULT
Nine studies involving 3,326,673 subjects were included. VZV infection was associated with an increased risk of dementia (HR = 1.11, 95% CI: 1.02-1.21). The risk of dementia was reduced in those who received antiviral therapy compared to those who did not (HR = 0.84, 95% CI: 0.71-0.99). In addition, VZV infection was found to be associated with an increased risk of developing dementia in the pooled results of the moderate quality study (HR = 1.81,95% CI: 1.27-2.59), and this association persisted when subgroup analyses were performed based on region (Asia: HR = 1.18,95% CI: 1.04-1.33).
CONCLUSIONS
Our results suggest that VZV infection might increase the risk of developing dementia, but there is no clear mechanism about the true relationship, and since there is no effective treatment for dementia, and our results suggest that some populations can benefit from antiviral therapy, it is at least arguable that patients who develop VZV infection should be treated with appropriate antiviral medications.
Topics: Humans; Antiviral Agents; Dementia; Herpes Zoster; Herpesvirus 3, Human
PubMed: 37639023
DOI: 10.1007/s10072-023-07038-7 -
PloS One 2023This study carried out a systematic literature review of economic evaluations of varicella vaccination programmes from the earliest publication to the present day,...
OBJECTIVES
This study carried out a systematic literature review of economic evaluations of varicella vaccination programmes from the earliest publication to the present day, including programmes in the workplace and in special risk groups as well as universal childhood vaccination and catch up programmes.
METHODS
Articles published from 1985 until 2022 were sourced from PubMed/Medline, Embase, Web of Science, NHSEED and Econlit. Eligible economic evaluations, which included posters and conference abstracts, were identified by two reviewers who scrutinised each other's selections at both title and abstract and full report stages. The studies are described in terms of their methodological characteristics. Their results are aggregated by type of vaccination programme and the nature of the economic outcome.
RESULTS
A total of 2575 articles were identified of which 79 qualified as economic evaluations. A total of 55 studies focused on universal childhood vaccination, 10 on the workplace and 14 on high risk groups. Twenty-seven studies reported estimates of incremental cost per quality-adjusted life year (QALY) gained, 16 reported benefit-cost ratios, 20 reported cost-effectiveness outcomes in terms of incremental cost per event or life saved and 16 reported cost-cost offset results. Most studies of universal childhood vaccination reported an increase in overall costs to health services, but often a reduction in cost from a societal perspective.
CONCLUSIONS
The evidence surrounding the cost-effectiveness of varicella vaccination programmes remains sparse with contrasting conclusions in some areas. Future research should particularly aim to encompass the impact of universal childhood vaccination programmes on herpes zoster among adults.
Topics: Adult; Humans; Chickenpox; Cost-Benefit Analysis; Herpes Zoster; Vaccination; Herpesvirus 3, Human; Quality-Adjusted Life Years
PubMed: 36972249
DOI: 10.1371/journal.pone.0282327 -
Expert Review of Vaccines May 2022Following COVID-19 vaccination, several herpes zoster cases have been reported, making it critical to explore the association between herpes zoster and COVID-19... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Following COVID-19 vaccination, several herpes zoster cases have been reported, making it critical to explore the association between herpes zoster and COVID-19 vaccination. This is especially true in the context of increasing the number of participants enrolled to receive COVID-19 vaccination.
RESEARCH DESIGN AND METHODS
Three databases, including the Cochrane Library, PubMed, and EMBASE, were searched for relevant studies before 25 December 2021 according to preliminarily determined inclusion and exclusion criteria without any language limitations. Four cohort studies were included in this systematic review and meta-analysis.
RESULTS
Compared with the placebo group, there was no evidence that the COVID-19 vaccination group was associated with increased incidence of herpes zoster (Risk ratio [RR]: 1.06; 95% confidence interval [CI]: 0.91 to 1.24). There is no evidence that the COVID-19 vaccination from Moderna is associated with the incidence of herpes zoster compared with vaccination from Pfizer (RR: 0.20; 95% CI: 0.01 to 2.99).
CONCLUSIONS
To date, there is no evidence of an association between covid-19 vaccination and herpes zoster.
Topics: COVID-19; COVID-19 Vaccines; Herpes Zoster; Herpes Zoster Vaccine; Herpesvirus 3, Human; Humans; Vaccination
PubMed: 35112938
DOI: 10.1080/14760584.2022.2036128 -
Journal of Neurovirology Apr 2022Neuromyelitis optica spectrum disorder (NMOSD) is a severe, inflammatory, immune-mediated astrocytopathy of the central nervous system, characterized by recurrent... (Review)
Review
Neuromyelitis optica spectrum disorder (NMOSD) is a severe, inflammatory, immune-mediated astrocytopathy of the central nervous system, characterized by recurrent inflammatory events primarily involving optic nerves and the spinal cord. Recently, a triggering role of infectious events in the development of NMOSD has been suggested. Varicella zoster virus (VZV) is the agent most involved, although the linkage with anti-aquaporin-4 antibodies is so far unknown. A review of the literature on the association between NMOSD and VZV infection was carried out by searching PUBMED and EMBASE from 1975 to July 2020. A total of 13 articles concerning Herpes zoster preceding NMOSD were identified. All patients were female and the median age at NMOSD presentation was 28.5 (range 5-63) years. Four NMOSD cases occurred after chicken pox while the remaining ten after HZ. Full recovery occurred in 5/14 patients. From the review of the literature, we can infer that VZV seems to trigger LETM attacks and not the disease itself. The strict temporal relationship between VZV infection and NMOSD seems to exceed the pure chance and represents an unusual clinical scenario posing several diagnostic and management challenges.
Topics: Aquaporin 4; Autoantibodies; Female; Herpes Zoster; Herpesvirus 3, Human; Humans; Male; Neuromyelitis Optica
PubMed: 35462584
DOI: 10.1007/s13365-022-01065-4 -
International Journal of Dermatology Sep 2022Although there is literature reporting correlations between varicella zoster virus (VZV) infections and COVID-19, insufficient evidence exists in this regard. This... (Review)
Review
BACKGROUND
Although there is literature reporting correlations between varicella zoster virus (VZV) infections and COVID-19, insufficient evidence exists in this regard. This scoping review aims to identify the existing evidence regarding clinical characteristics of primary VZV infection or reactivation in COVID-19.
METHODS
Following the PRISMA Extension for Scoping Reviews, MEDLINE and EMBASE were searched for all peer-reviewed articles with relevant keywords including "Zoster," "Herpes," and "COVID-19" from their inception to November 20, 2021.
RESULTS
A total of 19 articles with three observational studies and 16 case reports or series were included. Primary VZV infections or reactivation were observed in 25 patients. Forty-eight percent of the patients had disseminated VZV infection. The median time of VZV-related rash after the onset of respiratory symptoms was 7.0 days (interquartile range: 0-18.8). Those with COVID-19 and primary VZV infection or reactivation had low lymphocyte counts with a median of 0.67 × 10 /μl.
CONCLUSION
This scoping review identified uncertainty and a lack of strong evidence to see the association between primary VZV infection or reactivation and COVID-19. However, those with COVID-19 may be more likely to have disseminated VZV, which poses an additional challenge from an infection prevention standpoint. Future studies are warranted to determine the association between primary VZV infection or reactivation and long-term consequences related to COVID-19.
Topics: COVID-19; Herpes Zoster; Herpesvirus 3, Human; Humans
PubMed: 35503921
DOI: 10.1111/ijd.16221 -
Reviews in Medical Virology Jul 2024Stroke is a common worldwide cause of death and disability, resulting from an obstruction or reduction in blood flow to the brain. Research has demonstrated that... (Meta-Analysis)
Meta-Analysis Review
Stroke is a common worldwide cause of death and disability, resulting from an obstruction or reduction in blood flow to the brain. Research has demonstrated that systemic infection such as herpes zoster (HZ) / ophthalmicus herpes zoster (HZO) can potentially trigger stroke. This study includes an updated systematic review and meta-analysis of the epidemiologic data on the connection between HZ/HZO infection and the risk of stroke. A meticulous search of different database yielded 905 studies. Furthermore, an additional 14 studies from a previous meta-analysis were incorporated. Eligible studies underwent rigorous screening, resulting in 18 papers. Statistical analyses, including random/fixed effects models and subgroup analyses, were conducted to assess pooled relative risk (RR) and heterogeneity. The meta-analysis consisted of 5,505,885 participants and found a statistically significant association between HZ infection and the risk of stroke (pooled RR = 1.22, 95% confidence interval [CI] 1.12-1.34). The HZO infection showed a significantly higher overall pooled RR of 1.71 (95% CI 1.06-2.75), indicating a strong connection with the risk of stroke. Subgroup analysis revealed that the odds ratio might play a significant role in causing heterogeneity. Time since infection emerged as a crucial factor, with heightened stroke risk in the initial year post-HZ/HZO exposure, followed by a decline after the first year. Asian/Non-Asian studies demonstrated varied results in HZ/HZO patients. Meta-analysis reveals a significant HZ/HZO-stroke link. Subgroups highlight varied risks and warrant extended Asian/non-Asian patient investigation.
Topics: Humans; Stroke; Herpes Zoster; Risk Assessment; Risk Factors; Herpesvirus 3, Human
PubMed: 38853706
DOI: 10.1002/rmv.2556 -
Clinical Infectious Diseases : An... Sep 2019The "exogenous boosting hypothesis" postulates that reexposure to circulating varicella zoster virus (VZV) over the life span inhibits reactivation of VZV. Consequently,... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The "exogenous boosting hypothesis" postulates that reexposure to circulating varicella zoster virus (VZV) over the life span inhibits reactivation of VZV. Consequently, if circulation of VZV is suppressed by introduction of chickenpox vaccination, incidences of herpes zoster may rise.
METHODS
We performed a systematic review and metaanalysis on impact of chickenpox vaccination on herpes zoster incidence and time trend, focusing on population-level effects by analyzing interrupted time-series (ITS) studies. We searched Medline and Embase for ITS reporting incidences of chickenpox and herpes zoster before and after implementation of chickenpox vaccination. Autoregressive integrated moving average models were calculated. Change in trend and incidence from studies were pooled.
RESULTS
Twelve studies were included, of which 6 were eligible for metaanalysis. Metaanalysis revealed a significant increase in chickenpox cases prior to implementation of chickenpox vaccination and a reversed trend thereafter, particularly in individuals aged 1-4 years. The increase in age-adjusted herpes zoster incidence before implementation of chickenpox vaccination did not change thereafter. However, separate analysis of age groups revealed a net increase of hospitalized herpes zoster cases in individuals aged 10-49 years after implementation of chickenpox vaccination. This very small effect (fewer than 2 additional cases per 100 000 persons) did not occur in other age groups.
CONCLUSIONS
To date, no conclusive evidence exists that chickenpox vaccination has a substantial population-level impact on herpes zoster in nonvaccinated age groups. While exogenous boosting may exist, the effect size generated by chickenpox vaccination might be rather small on the population level.
Topics: Chickenpox; Chickenpox Vaccine; Herpes Zoster; Herpesvirus 3, Human; Humans; Incidence; Interrupted Time Series Analysis; Risk; Vaccination
PubMed: 30590491
DOI: 10.1093/cid/ciy1099