Impact of universal vaccination against varicella in Italy

Economic burden of varicella in Bangkok, Thailand: A multicenter medical chart review study

Our multicenter, medical chart review, cost-of-illness study used a micro-costing approach to evaluate the economic burden associated with varicella in Bangkok, Thailand, from a societal perspective. We reviewed medical charts of adults and children with a primary diagnosis of varicella (2014-2018) from 4 hospitals in Bangkok. Reported healthcare resource utilization and missed school or workdays were extracted from medical charts. Mean direct, indirect, and total costs per patient were estimated for overall, adult, and pediatric patients (2020 USD). Of the 200 children and 60 adults, 99.6%, 5.4%, and 5.4% had a varicella-related outpatient visit, emergency department visit, and hospitalization, respectively. The mean direct medical cost was 33 USD for pediatric and adult patients. The mean cost of outpatient visits (8 vs 13 USD, P<0.001) and medications (7 vs 9 USD, P<0.001) was significantly lower among pediatric patients. Forty-eight children reported a mean of 5.8 school days lost, and 32 adult patients reported a mean of 7.4 workdays lost. The mean total cost per varicella patient was 89 USD, with the mean total cost higher for adult than pediatric patients (145 vs 72 USD, P<0.001). Indirect cost accounted for 63% of the total cost per patient (54% for pediatric patients and 77% for adult patients). There is a substantial economic burden associated with patients seeking varicella-related healthcare in Thailand, including considerable indirect costs.

Antimicrobial use for the management of varicella in Thailand: a retrospective observational study

OBJECTIVE

To describe the clinical characteristics of varicella patients seeking medical consultation and the use of antimicrobials for their management in Thailand in the absence of universal varicella vaccination (UVV).

METHODS

A multicenter, retrospective chart review of 260 children and adults with a primary diagnosis of varicella was conducted at one private and three public hospitals in Bangkok, Thailand. Charts of varicella patients (inpatient or outpatient) were randomly selected over a 5-year period. Key outcomes included clinical complications and the use of antibiotics, antivirals, and other medications.

RESULTS

Charts of 200 children (mean age 5.7 years, range 0.3-16 years) and 60 adults (mean age 27.9 years, range 18-50 years) were reviewed. Fourteen patients (including 8 children) were hospitalized. Five percent of the children and none of the adults were immunocompromised. At least 1 varicella-related complication was reported by 7.3% (7% of children, 8.3% of adults, p = .778) of all patients, including 57.1% (62.5% of children, 50% of adults) of inpatients (p < .001, compared with outpatients). Skin/soft tissue infection (47.7%) and dehydration (47.4%) were the most common complications. Antivirals (mainly oral acyclovir) were prescribed to 46.5% of patients (31.5% of children, 96.7% of adults, p < .001). Antibiotics were prescribed to 20.8% of patients (19% of children, 26.7% of adults, p = .199). Topical, oral, and intravenous antibiotics were prescribed to 12.3%, 8.5%, and 1.2% of patients, respectively. Antimicrobial prescriptions were higher among adults (p < .001) and immunocompromised patients (p = .025). Apart from antimicrobials, acetaminophen (62.3%) and oral antihistamines (51.5%) were the most prescribed.

CONCLUSION

A considerable number of varicella patients, both children and adults, seeking medical consultation in Thai hospitals are prescribed antibiotics and antivirals, with one-fifth of patients being prescribed an antibiotic and almost half prescribed an antiviral. The study may be of interest to policymakers in Thailand and other Asia-Pacific countries considering UVV implementation.

Sero-Epidemiological Study of Varicella in the Italian General Population

The aim of this study was to analyze the seroprevalence of varicella in Italy and to evaluate the impact of varicella vaccination, which has been mandatory for newborns since 2017. The levels of VZV-specific IgG antibodies were determined by the ELISA method in residual serum samples obtained from subjects aged between 6 and 64 years and residing in 13 Italian regions. Overall, 3746 serum samples were collected in the years 2019 and 2020. The overall seroprevalence was 91.6% (89.9% in males and 93.3% in females; p = 0.0002). Seroprevalence showed an increasing trend (p < 0.0001) starting in the younger age groups: 6-9 years: 84.1%; 10-14 years: 88.7%; 15-19 years: 89.3%; 20-39 years: 93.1% and >40 years: 97.0%. The seroprevalence data obtained in the present study were compared with those relating to previous sero-epidemiological surveys conducted, respectively, in the years 1996-1997, 2003-2004 and 2013-2014, taking into consideration only data from regions monitored in all surveillance campaigns. The comparison highlighted for the period 2019-2020 showed significantly higher values in the age groups 6-9 (p < 0.001), 10-14 (p = 0.018) and 15-19 years (p = 0.035), while in adults, the trend did not change over time (ns). These results highlight the positive impact of varicella vaccination in Italy.

Prevalence and management of rubella susceptibility in healthcare workers in Italy: A systematic review and meta-analysis

Introduction

In the pre-vaccination era, all adults acquired immunity status due to natural infections during childhood and adolescence, whereas universal mass vaccination has changed the seroepidemiology of rubella among adults, showing lack of immunity in some subgroups. National and international guidelines recommend evaluating all healthcare workers (HCWs) for their immune status to rubella and possibly vaccinating those who are seronegative. We conducted a systematic review and meta-analysis to estimate the susceptibility rate to rubella among HCWs in Italy and to explore possible options for the management of those found to be susceptible.

Methods

Eight studies were included in the meta-analysis, selected from scientific papers available in the MEDLINE/PubMed and Google Scholar (till page 10) databases between January 1, 2015 and November 30, 2021. The following terms were used for the search strategy: (sero* OR seroprevalence OR prevalence OR susceptibilit* OR immunit* OR immunogenict*) AND (healthcare worker* OR health personnel OR physician* OR nurse OR student*) AND (rubella OR german measles OR TORCH) AND (Italy)

Results

The prevalence of rubella-susceptible HCWs was 9.0 % (95 %CI: 6.4–12.1 %). In a comparison of female vs. male serosusceptible HCWs, the RR was 0.67 (95 %CI = 0.51–0.88). Occupational medicine examinations for rubella screening with possible subsequent vaccination of seronegatives and exclusion of susceptible HCWs from high-risk settings were common management strategies.

Conclusions

HCWs susceptible to rubella are an important epidemiological concern in Italy, and efforts to identify and actively offer the vaccine to this population should be increased.

Global varicella vaccination programs

Varicella (chickenpox) is an infectious disease caused by the highly contagious varicella zoster virus with a secondary attack rate greater than 90%. From this perspective, we aimed to establish the basis for a national varicella vaccine policy by reviewing vaccination programs and policies of countries that have introduced universal varicella vaccinations. As a result of the spread of varicella, an increasing number of countries are providing 2-dose vaccinations and universally expanding their use. In practice, the efficacy and effectiveness of vaccination differ among vaccines and vaccination programs. Optimized vaccination strategies based on each country's local epidemiology and health resources are required. Accordingly, it is necessary to evaluate the effectiveness of varicella vaccines in different settings. Given the short-term and fragmented vaccine effectiveness evaluation in Korea, it is necessary to evaluate its effectiveness at the national level and determine its schedule based on the evidence generated through these studies.

The health and economic impact of switching vaccines in universal varicella vaccination programs using a dynamic transmission model: An Israel case study

Currently available health economic models for varicella infection are designed to inform the cost-effectiveness of universal varicella vaccination (UVV) compared with no vaccination. However, in countries with an existing UVV program, these models cannot be used to evaluate whether to continue with the current varicella vaccine or to switch to an alternative vaccine. We developed a dynamic transmission model that incorporates the historical vaccination program to project the health and economic impact of changing vaccination strategies. We applied the model to Israel, which initiated UVV in 2008 with a quadrivalent vaccine, MMRV-GSK, and switched to MMRV-MSD in 2016. The model was calibrated to pre-vaccination incidence data before projecting the impact of the historical and future alternative vaccination strategies on the clinical burden of varicella. Total costs and QALYs lost due to varicella infections were projected to compare continuing with MMRV-MSD versus switching to MMRV-GSK in 2022. Over a 50-year time horizon, continuing with MMRV-MSD reduced varicella incidence further by 64%, reaching 35 cases per 100,000 population by 2072, versus a 136% increase in incidence with MMRV-GSK. Continuing with MMRV-MSD reduced cumulative hospitalization and outpatient cases by 48% and 58% (vs. increase of 137% and 91% with MMRV-GSK), respectively. Continuing with MMRV-MSD resulted in 139 fewer QALYs lost with total cost savings of 3% compared with switching to MMRV-GSK, from the societal perspective. In Israel, maintaining the UVV strategy with MMRV-MSD versus switching to MMRV-GSK is projected to further reduce the burden of varicella and cost less from the societal perspective.

Economic burden of varicella in Europe in the absence of universal varicella vaccination

Background

Though the disease burden of varicella in Europe has been reported previously, the economic burden is still unknown. This study estimated the economic burden of varicella in Europe in the absence of Universal Varicella Vaccination (UVV) in 2018 Euros from both payer (direct costs) and societal (direct and indirect costs) perspectives.

Methods

We estimated the country specific and overall annual costs of varicella in absence of UVV in 31 European countries (27 EU countries, plus Iceland, Norway, Switzerland and the United Kingdom). To obtain country specific unit costs and associated healthcare utilization, we conducted a systematic literature review, searching in PubMed, EMBASE, NEED, DARE, REPEC, Open Grey, and public heath websites (1/1/1999–10/15/2019). The number of annual varicella cases, deaths, outpatient visits and hospitalizations were calculated (without UVV) based on age-specific incidence rates (Riera-Montes et al. 2017) and 2018 population data by country. Unit cost per varicella case and disease burden data were combined using stochastic modeling to estimate 2018 costs stratified by country, age and healthcare resource.

Results

Overall annual total costs associated with varicella were estimated to be €662,592,061 (Range: €309,552,363 to €1,015,631,760) in Europe in absence of UVV. Direct and indirect costs were estimated at €229,076,206 (Range €144,809,557 to €313,342,856) and €433,515,855 (Range €164,742,806 to €702,288,904), respectively. Total cost per case was €121.45 (direct: €41.99; indirect: €79.46). Almost half of the costs were attributed to cases in children under 5 years, owing mainly to caregiver work loss. The distribution of costs by healthcare resource was similar across countries. France and Germany accounted for 49.28% of total annual costs, most likely due to a combination of high numbers of cases and unit costs in these countries.

Conclusions

The economic burden of varicella across Europe in the absence of UVV is substantial (over 600 M€), primarily driven by caregiver burden including work productivity losses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12343-x.

Vaccines for measles, mumps, rubella, and varicella in children

BACKGROUND

Measles, mumps, rubella, and varicella (chickenpox) are serious diseases that can lead to serious complications, disability, and death. However, public debate over the safety of the trivalent MMR vaccine and the resultant drop in vaccination coverage in several countries persists, despite its almost universal use and accepted effectiveness. This is an update of a review published in 2005 and updated in 2012.

OBJECTIVES

To assess the effectiveness, safety, and long- and short-term adverse effects associated with the trivalent vaccine, containing measles, rubella, mumps strains (MMR), or concurrent administration of MMR vaccine and varicella vaccine (MMR+V), or tetravalent vaccine containing measles, rubella, mumps, and varicella strains (MMRV), given to children aged up to 15 years.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2019, Issue 5), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to 2 May 2019), Embase (1974 to 2 May 2019), the WHO International Clinical Trials Registry Platform (2 May 2019), and ClinicalTrials.gov (2 May 2019).

SELECTION CRITERIA

We included randomised controlled trials (RCTs), controlled clinical trials (CCTs), prospective and retrospective cohort studies (PCS/RCS), case-control studies (CCS), interrupted time-series (ITS) studies, case cross-over (CCO) studies, case-only ecological method (COEM) studies, self-controlled case series (SCCS) studies, person-time cohort (PTC) studies, and case-coverage design/screening methods (CCD/SM) studies, assessing any combined MMR or MMRV / MMR+V vaccine given in any dose, preparation or time schedule compared with no intervention or placebo, on healthy children up to 15 years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the methodological quality of the included studies. We grouped studies for quantitative analysis according to study design, vaccine type (MMR, MMRV, MMR+V), virus strain, and study settings. Outcomes of interest were cases of measles, mumps, rubella, and varicella, and harms. Certainty of evidence of was rated using GRADE.

MAIN RESULTS

We included 138 studies (23,480,668 participants). Fifty-one studies (10,248,159 children) assessed vaccine effectiveness and 87 studies (13,232,509 children) assessed the association between vaccines and a variety of harms. We included 74 new studies to this 2019 version of the review. Effectiveness Vaccine effectiveness in preventing measles was 95% after one dose (relative risk (RR) 0.05, 95% CI 0.02 to 0.13; 7 cohort studies; 12,039 children; moderate certainty evidence) and 96% after two doses (RR 0.04, 95% CI 0.01 to 0.28; 5 cohort studies; 21,604 children; moderate certainty evidence). The effectiveness in preventing cases among household contacts or preventing transmission to others the children were in contact with after one dose was 81% (RR 0.19, 95% CI 0.04 to 0.89; 3 cohort studies; 151 children; low certainty evidence), after two doses 85% (RR 0.15, 95% CI 0.03 to 0.75; 3 cohort studies; 378 children; low certainty evidence), and after three doses was 96% (RR 0.04, 95% CI 0.01 to 0.23; 2 cohort studies; 151 children; low certainty evidence). The effectiveness (at least one dose) in preventing measles after exposure (post-exposure prophylaxis) was 74% (RR 0.26, 95% CI 0.14 to 0.50; 2 cohort studies; 283 children; low certainty evidence). The effectiveness of Jeryl Lynn containing MMR vaccine in preventing mumps was 72% after one dose (RR 0.24, 95% CI 0.08 to 0.76; 6 cohort studies; 9915 children; moderate certainty evidence), 86% after two doses (RR 0.12, 95% CI 0.04 to 0.35; 5 cohort studies; 7792 children; moderate certainty evidence). Effectiveness in preventing cases among household contacts was 74% (RR 0.26, 95% CI 0.13 to 0.49; 3 cohort studies; 1036 children; moderate certainty evidence).  Vaccine effectiveness against rubella, using a vaccine with the BRD2 strain which is only used in China, is 89% (RR 0.11, 95% CI 0.03 to 0.42; 1 cohort study; 1621 children; moderate certainty evidence).  Vaccine effectiveness against varicella (any severity) after two doses in children aged 11 to 22 months is 95% in a 10 years follow-up (rate ratio (rr) 0.05, 95% CI 0.03 to 0.08; 1 RCT; 2279 children; high certainty evidence). Safety There is evidence supporting an association between aseptic meningitis and MMR vaccines containing Urabe and Leningrad-Zagreb mumps strains, but no evidence supporting this association for MMR vaccines containing Jeryl Lynn mumps strains (rr 1.30, 95% CI 0.66 to 2.56; low certainty evidence). The analyses provide evidence supporting an association between MMR/MMR+V/MMRV vaccines (Jeryl Lynn strain) and febrile seizures. Febrile seizures normally occur in 2% to 4% of healthy children at least once before the age of 5. The attributable risk febrile seizures vaccine-induced is estimated to be from 1 per 1700 to 1 per 1150 administered doses. The analyses provide evidence supporting an association between MMR vaccination and idiopathic thrombocytopaenic purpura (ITP). However, the risk of ITP after vaccination is smaller than after natural infection with these viruses. Natural infection of ITP occur in 5 cases per 100,000 (1 case per 20,000) per year. The attributable risk is estimated about 1 case of ITP per 40,000 administered MMR doses. There is no evidence of an association between MMR immunisation and encephalitis or encephalopathy (rate ratio 0.90, 95% CI 0.50 to 1.61; 2 observational studies; 1,071,088 children; low certainty evidence), and autistic spectrum disorders (rate ratio 0.93, 95% CI 0.85 to 1.01; 2 observational studies; 1,194,764 children; moderate certainty). There is insufficient evidence to determine the association between MMR immunisation and inflammatory bowel disease (odds ratio 1.42, 95% CI 0.93 to 2.16; 3 observational studies; 409 cases and 1416 controls; moderate certainty evidence). Additionally, there is no evidence supporting an association between MMR immunisation and cognitive delay, type 1 diabetes, asthma, dermatitis/eczema, hay fever, leukaemia, multiple sclerosis, gait disturbance, and bacterial or viral infections.  AUTHORS' CONCLUSIONS: Existing evidence on the safety and effectiveness of MMR/MMRV vaccines support their use for mass immunisation. Campaigns aimed at global eradication should assess epidemiological and socioeconomic situations of the countries as well as the capacity to achieve high vaccination coverage. More evidence is needed to assess whether the protective effect of MMR/MMRV could wane with time since immunisation.

Assessing the use of antibiotics and the burden of varicella in Belgium using a retrospective GP database analysis

Background

Varicella is a highly contagious infection that typically occurs in childhood. While most cases have a generally benign outcome, infection results in a considerable healthcare burden and serious complications may occur.

Objectives

The objective of this study was to characterize the burden of varicella in a real-world primary care setting in Belgium, including the rate of varicella-related complications, medication management and general practitioner (GP) visits.

Methods

The study was a retrospective observational study using data from a longitudinal patient database in a primary care setting in Belgium. Patients with a GP visit and a varicella diagnosis between January 2016 and June 2019 were eligible and data one month prior and three months after the diagnosis were included. Outcomes included varicella-related complications, antibiotic use, antiviral use, and GP follow-up visits. Antibiotic use could be specified by class of antibiotic and linked to a diagnosis. Complications were identified based on concomitant diagnosis with varicella during the study period.

Results

3,847 patients with diagnosis of varicella were included, with a mean age of 8.4 years and a comparable distribution of gender. 12.6% of patients with varicella had a concomitant diagnosis of a varicella-related complication. During the follow-up period, 27.3% of patients with varicella were prescribed antibiotics, either systemic (19.8%) and/or topical (10.3%). The highest rate of antibiotic prescriptions was observed in patients with complications (63.5%) and in patients younger than 1 year (41.8%). Nevertheless, 5.3% of the patients were prescribed antibiotics without a concomitant diagnosis of another infection. The most commonly prescribed systemic antibiotics were amoxicillin alone or combined with beta-lactamase inhibitor, and thiamphenicol. Fusidic acid and tobramycin were the most prescribed topical antibiotics. Antivirals were prescribed for 2.7% of the study population. 4.7% of the patients needed a follow-up visit with their GP.

Conclusions

This study reports a substantial burden of varicella in a primary care setting in Belgium, with high rates of complications and antibiotic use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06848-4.

Survey among Italian experts on existing vaccines' role in limiting antibiotic resistance

Antimicrobial resistance (AMR) is a major public health problem threatening to reverse the progress made against infectious diseases. The rapid increase of AMR exposes Italian hospitals at increased risk of untreatable infections. Vaccinations can potentially limit AMR by reducing the number of infected cases in need of antibiotics. We conducted a survey among Italian vaccine experts to record their opinion regarding the role of vaccinations against antibiotic resistance (ABR). Among 80 invited experts, 51 answered all questions. Most respondents were experts in hygiene and preventive medicine (56.9%) and aged >50 years (72.6%). ABR was a priority concern in the daily professional activity of 82.4% of respondents. Overall, 47.1% of respondents believed that all vaccinations included in the vaccination calendar played a role against ABR: 92.2% for pertussis vaccination followed by 88.2%, 74.5%, and 70.6% for meningococcus, measles, and varicella vaccinations, respectively. Almost all respondents agreed that the role of vaccinations against ABR should be clearly expressed in the national vaccination guidelines (96.1%) and Scientific Societies should take an explicit position on the issue (92.2%). These results show that Italian experts have recognized the vaccinations’ potential role in limiting ABR and guidelines from the appropriate scientific and governmental authorities are needed.

Impact of six years of routine varicella vaccination on the disease-related hospitalizations at Minas Gerais, Brazil

INTRODUCTION

The varicella vaccine was first introduced into the Brazilian immunization schedule in September 2013 as a single dose for children aged 15 months. In 2018, a second dose was recommended for individuals between 4 and 6 years old. This study aims to assess the impact of routine varicella vaccination on the number and profile of hospitalized varicella patients during the single dose period, as well as in the first two years after the adoption of the second dose.

METHODS

An observational retrospective study was conducted in an infectious disease pediatric hospital, in Minas Gerais, Brazil. Clinical as well as epidemiological data from patients hospitalized due to varicella between 2010 and 2019 were collected. Patients were split into groups based on the vaccine introduction: pre-vaccine period, single dose and two-dose period. They were compared by age, sex, reason for admission, illness-related complications and clinical outcome.

RESULTS

There were 1193 admissions due to varicella during the studied period. When compared with the pre-vaccine period, the number of hospitalizations decreased in 61.5% during the single-dose regime, reaching 95.2% in the two-dose period. Hospitalization rates decreased in all age groups, including non-vaccinated individuals such as those younger than 12 months (92.1%). As for reasons of admission, secondary bacterial skin infections were perceived to be the most common cause (>70%). A reduction was also seen in admission of immunocompromised or HIV positive patients (84.8%).

CONCLUSION

The collected data shows a significant impact in the number of hospital admissions due to varicella after six years of the implementation of the vaccine, positively affecting both vaccinated and non-vaccinated individuals. Further reduction was seen after the second dose was initiated, but its true impact will only be understood fully after a longer period of continuous vaccination.

Acceptance of varicella vaccination

Varicella is a common vaccine-preventable disease that usually presents in children as a mild infection; however, severe complications also occur. The burden of varicella is significant in the terms of incidence, complication, and hospitalization rate related to varicella and economic disease burden. Despite the evidence of overall positive effects of varicella vaccination, there are great differences in the implementation of varicella vaccination and in the uptake of the vaccine from country to country. Improving acceptance of varicella vaccination on the national and on the individual level would decrease the burden of the disease on the health of children and on health-care resources. In studies determining factors of parental acceptance of varicella vaccination questions specific for varicella vaccination were highlighted. Addressing these issues with open, evidence based communication is important to improve and maintain the trust of the public in varicella vaccination.

A Study of Varicella Seroprevalence in a Pediatric and Adolescent Population in Florence (Italy). Natural Infection and Vaccination-Acquired Immunization

Background: Varicella is a well-known infectious disease that can have severe complications, also in young children. The Universal Varicella Vaccination (UVV) program was introduced in Tuscany (Italy) in 2003, with a two-dose vaccine schedule given to children between their 13th and 15th month, and at 5–6 years old, as a monovalent for varicella (V) or tetravalent (measles, mumps, rubella and varicella (MMRV)) formulation. Although varicella notifications have dramatically fallen in the last two decades, varicella disease underreporting remains a challenge. Methods: A qualitative immunoenzymatic test (ELISA) was used to measure the presence of anti-varicella antibodies in 165 sera of subjects aged 1–18 years residing in the province of Florence (Italy). Information regarding the anamnestic and vaccination status (including disease notification) was also collected. Results: Our study showed an overall varicella seropositivity of 75.8% (reaching the maximum at 96.3% in the 15–18 years age group). We found that varicella disease notification had been recorded for only 7/165 subjects; however, since 42/165 recalled having had the disease, we can hypothesize that some of them must have been underreported. Furthermore, our study showed that the presence of antibodies after the varicella vaccination remained over time, lasting up to 12 years. Conclusions: Although varicella seroprevalence is <95% in almost all our age groups (except for the 15–18 years age group), our data are encouraging and reflect the success of the introduction of the UVV program and the vaccination campaigns promoted in the Tuscany region.

Acceptance of universal varicella vaccination among Swiss pediatricians and general practitioners who treat pediatric patients

Background

Over the last two decades, several countries have initiated universal varicella vaccination (UVV) programs in infants. In 2019, the Swiss National Immunization Technical Advisory Group (NITAG) decided to start evaluating the introduction of universal varicella vaccination. There is a theoretical concern that suboptimal vaccination coverage could lead to a shift in the varicella incidence to older age groups, thereby potentially increasing complication rates. To achieve a high vaccination coverage rate, it is important that practicing physicians comply with a potential recommendation for UVV.

We studied the perception of varicella and the current vaccination behavior among Swiss pediatricians and general practitioners (GPs) who treat children. We also assessed their intention to advise parents to vaccinate their children against varicella in the event the Swiss NITAG will recommend UVV.

Methods

Primary data was collected through a structured, 20-min online survey with Swiss pediatricians and GPs who treat children.

Results

150 physicians participated in the study: 40 GPs in the German-speaking part, 20 GPs in the French-speaking part, 67 pediatricians in the German-speaking part, and 23 pediatricians in the French-speaking part.

The majority (64%) of all participants reported that they currently recommend varicella vaccination for risk groups according to the national immunization plan. About one third of physicians (35%) – predominantly pediatricians – currently already recommend it for all infants. In these situations, a measles, mumps, rubella, varicella combination vaccine is currently used by 58% for the first dose and by 59% for the second dose.

86% of participants stated that they would advise parents to have their children vaccinated against varicella in case of a recommendation for UVV by the Swiss NITAG. 68% responded that they expect many questions from parents and 65% agreed that they have good arguments to convey the importance of varicella vaccination.

Conclusions

The survey study results show that most participating pediatricians and GPs indicated a favorable attitude towards childhood vaccination against varicella in the setting of a Swiss NITAG recommendation for UVV. This data shows the importance of NITAG recommendations in influencing vaccine education and supporting achievement of high coverage of varicella vaccination.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05586-3.

Varicella seroepidemiology and immunization in a cohort of future healthcare workers in the pre-vaccination era

OBJECTIVES

The goal of this study was to establish the seroprevalence of positive antibodies against varicella and compliance with varicella vaccination in the pre-vaccination era.

METHODS

A cohort of 10 683 Italian students from Padua University Medical School (from 2004 to 2019) were enrolled and classified as unvaccinated, vaccinated once, or vaccinated twice against varicella, according to their vaccination certificate. The antibody titre was measured and the seroprevalence of positive subjects was determined. Subjects with negative or equivocal antibodies were invited for vaccination, and then the antibody titre was retested.

RESULTS

Unvaccinated students were mostly seropositive (95.6%), compared with vaccinated students who were less seropositive (68.0% after one dose and 78.6% after two doses) and had significantly lower antibody titres (p < 0.0001). The post-test vaccination had a positive response rate of 85.4%: 67.4% after one dose and 91.4% after two doses.

CONCLUSIONS

In the pre-vaccination era, only 3.3% of future healthcare workers were vaccinated against varicella (1.1% once and 2.2% twice). Vaccination or revaccination of negative and equivocal individuals could reduce the number of susceptible people. Implementation of varicella vaccine (two doses) in healthcare workers is of primary importance to reduce the risk of transmission.

Vaccines for measles, mumps, rubella, and varicella in children

BACKGROUND

Measles, mumps, rubella, and varicella (chickenpox) are serious diseases that can lead to serious complications, disability, and death. However, public debate over the safety of the trivalent MMR vaccine and the resultant drop in vaccination coverage in several countries persists, despite its almost universal use and accepted effectiveness. This is an update of a review published in 2005 and updated in 2012.

OBJECTIVES

To assess the effectiveness, safety, and long- and short-term adverse effects associated with the trivalent vaccine, containing measles, rubella, mumps strains (MMR), or concurrent administration of MMR vaccine and varicella vaccine (MMR+V), or tetravalent vaccine containing measles, rubella, mumps, and varicella strains (MMRV), given to children aged up to 15 years.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2019, Issue 5), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to 2 May 2019), Embase (1974 to 2 May 2019), the WHO International Clinical Trials Registry Platform (2 May 2019), and ClinicalTrials.gov (2 May 2019).

SELECTION CRITERIA

We included randomised controlled trials (RCTs), controlled clinical trials (CCTs), prospective and retrospective cohort studies (PCS/RCS), case-control studies (CCS), interrupted time-series (ITS) studies, case cross-over (CCO) studies, case-only ecological method (COEM) studies, self-controlled case series (SCCS) studies, person-time cohort (PTC) studies, and case-coverage design/screening methods (CCD/SM) studies, assessing any combined MMR or MMRV / MMR+V vaccine given in any dose, preparation or time schedule compared with no intervention or placebo, on healthy children up to 15 years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the methodological quality of the included studies. We grouped studies for quantitative analysis according to study design, vaccine type (MMR, MMRV, MMR+V), virus strain, and study settings. Outcomes of interest were cases of measles, mumps, rubella, and varicella, and harms. Certainty of evidence of was rated using GRADE.

MAIN RESULTS

We included 138 studies (23,480,668 participants). Fifty-one studies (10,248,159 children) assessed vaccine effectiveness and 87 studies (13,232,509 children) assessed the association between vaccines and a variety of harms. We included 74 new studies to this 2019 version of the review. Effectiveness Vaccine effectiveness in preventing measles was 95% after one dose (relative risk (RR) 0.05, 95% CI 0.02 to 0.13; 7 cohort studies; 12,039 children; moderate certainty evidence) and 96% after two doses (RR 0.04, 95% CI 0.01 to 0.28; 5 cohort studies; 21,604 children; moderate certainty evidence). The effectiveness in preventing cases among household contacts or preventing transmission to others the children were in contact with after one dose was 81% (RR 0.19, 95% CI 0.04 to 0.89; 3 cohort studies; 151 children; low certainty evidence), after two doses 85% (RR 0.15, 95% CI 0.03 to 0.75; 3 cohort studies; 378 children; low certainty evidence), and after three doses was 96% (RR 0.04, 95% CI 0.01 to 0.23; 2 cohort studies; 151 children; low certainty evidence). The effectiveness (at least one dose) in preventing measles after exposure (post-exposure prophylaxis) was 74% (RR 0.26, 95% CI 0.14 to 0.50; 2 cohort studies; 283 children; low certainty evidence). The effectiveness of Jeryl Lynn containing MMR vaccine in preventing mumps was 72% after one dose (RR 0.24, 95% CI 0.08 to 0.76; 6 cohort studies; 9915 children; moderate certainty evidence), 86% after two doses (RR 0.12, 95% CI 0.04 to 0.35; 5 cohort studies; 7792 children; moderate certainty evidence). Effectiveness in preventing cases among household contacts was 74% (RR 0.26, 95% CI 0.13 to 0.49; 3 cohort studies; 1036 children; moderate certainty evidence). Vaccine effectiveness against rubella is 89% (RR 0.11, 95% CI 0.03 to 0.42; 1 cohort study; 1621 children; moderate certainty evidence). Vaccine effectiveness against varicella (any severity) after two doses in children aged 11 to 22 months is 95% in a 10 years follow-up (rate ratio (rr) 0.05, 95% CI 0.03 to 0.08; 1 RCT; 2279 children; high certainty evidence). Safety There is evidence supporting an association between aseptic meningitis and MMR vaccines containing Urabe and Leningrad-Zagreb mumps strains, but no evidence supporting this association for MMR vaccines containing Jeryl Lynn mumps strains (rr 1.30, 95% CI 0.66 to 2.56; low certainty evidence). The analyses provide evidence supporting an association between MMR/MMR+V/MMRV vaccines (Jeryl Lynn strain) and febrile seizures. Febrile seizures normally occur in 2% to 4% of healthy children at least once before the age of 5. The attributable risk febrile seizures vaccine-induced is estimated to be from 1 per 1700 to 1 per 1150 administered doses. The analyses provide evidence supporting an association between MMR vaccination and idiopathic thrombocytopaenic purpura (ITP). However, the risk of ITP after vaccination is smaller than after natural infection with these viruses. Natural infection of ITP occur in 5 cases per 100,000 (1 case per 20,000) per year. The attributable risk is estimated about 1 case of ITP per 40,000 administered MMR doses. There is no evidence of an association between MMR immunisation and encephalitis or encephalopathy (rate ratio 0.90, 95% CI 0.50 to 1.61; 2 observational studies; 1,071,088 children; low certainty evidence), and autistic spectrum disorders (rate ratio 0.93, 95% CI 0.85 to 1.01; 2 observational studies; 1,194,764 children; moderate certainty). There is insufficient evidence to determine the association between MMR immunisation and inflammatory bowel disease (odds ratio 1.42, 95% CI 0.93 to 2.16; 3 observational studies; 409 cases and 1416 controls; moderate certainty evidence). Additionally, there is no evidence supporting an association between MMR immunisation and cognitive delay, type 1 diabetes, asthma, dermatitis/eczema, hay fever, leukaemia, multiple sclerosis, gait disturbance, and bacterial or viral infections.

AUTHORS' CONCLUSIONS

Existing evidence on the safety and effectiveness of MMR/MMRV vaccines support their use for mass immunisation. Campaigns aimed at global eradication should assess epidemiological and socioeconomic situations of the countries as well as the capacity to achieve high vaccination coverage. More evidence is needed to assess whether the protective effect of MMR/MMRV could wane with time since immunisation.

Immunization Status against Measles, Mumps, Rubella and Varicella in a Large Population of Internationally Adopted Children Referred to Meyer Children's University Hospital from 2009 to 2018

Control of vaccine preventable diseases (VPDs) is a challenge for healthcare systems. Different studies highlighted the suboptimal immunization of internationally adopted children (IAC). To evaluate the immunization status against measles, mumps, rubella (MMR), and varicella (V) in a large cohort of IAC, data at first screening visit of all IAC (<18 years) consecutively referred to Meyer Children's University Hospital (Florence, Italy) from 2009 to 2018 were collected and analyzed. In total, 1927 children (median age: 5.99 years, interquartile range: 3.33-8.21) were enrolled. More than half of IAC were unprotected against MMR-V. The reliability of the vaccination documentation of the country of origin was poor, since more than a quarter of the IAC serologically tested were not protected against MMR-V, despite the vaccination documentation attesting previous vaccination. This was significantly more pronounced in children aged 15-18 years and in those originating from Africa. High rate of discordant serological results/documentation brings up questions regarding the optimal management of IACs, and suggests a rapid, careful, and complete assessment of immunization status timely after IAC's arrival. Serological testing of IAC of all ages followed by vaccination of seronegative children should be provided.

Impact of vaccination on the incidence of varicella hospitalizations in a state in Southeast Brazil

INTRODUCTION

This study aimed to analyze cases of complicated varicella and the impact of varicella vaccination in Minas Gerais, Brazil.

METHODS

This was a time series study of a territorial basis using data on varicella cases from 2010 to 2016, which was provided by the State Health Department of Minas Gerais on . Descriptive statistics were used for the analysis, and the generalized linear regression model proposed by Prais-Winsten was used for the time tendency, adopting a significance level of 5% and the integrated autoregressive modeling of moving averages.

RESULTS

There were 1,635 cases of varicella; out of which cellulitis (44%) was the predominant complication. The home-acquired cases were 38.9% and 464 cases (40.6%) were not previously vaccinated. There was a significant decrease in the incidence coefficient when comparing the pre- and post- immunization periods, from 1.95 cases/100,000 inhabitants in 2010 to 0.24 cases/100.000 inhabitants in 2016 (p<0.05). There was a higher incidence of cases recorded among males, with higher prevalence in the age group of 1-4 years (54.7%). Lethality was higher between 5-9 years of age (44%). Mortality was higher in the age group of 0-4 years and among females (2.58/100,000 inhabitants/year). The overall trend of the incidence coefficient was a decreasing one, with an annual percentage variation.

CONCLUSIONS

The number of complicated varicella cases notified decreased, coincidentally, in the post-immunization period. However, the immunization coverage period was restricted for the assessment of the correlation between immunization coverage and incidence.

Evaluation of impact of one dose varicella vaccine on the incidence of chickenpox in Argentina

INTRODUCTION

Varicella, also known as chickenpox is one of the most common immunizable diseases. In 1998, the World Health Organization (WHO) recommended to incorporate this vaccine in the national immunization programs, which Argentina did in 2015.

OBJECTIVES

To describe the behavior of the varicella time series for the 2005-2017 period, and to evaluate the impact of the vaccine in Argentina.

METHODOLOGY

An ecological observational study was performed, using the varicella cases reported in the National Health Monitoring System, and the data of the National census as secondary data sources. A model based time series analysis of the notified varicella cases in Argentina was performed, using a Negative Binomial Mixed Model. For the verification of the vaccine impact, the 2005-2014 period was selected, and a prognosis for the following years was performed. Impact was evaluated by comparing the rates and confidence intervals between the predicted and observed values.

RESULTS

Argentina reported 1,775,587 varicella cases for the 2005-2017 period. The series exhibited seasonality, and, a decreasing trend in the number of cases was observed in 2016 and 2017. A reduction of the incidence rate after the implementation of the vaccine was observed. The transmission risk decreased in the country after vaccine implementation.

CONCLUSIONS

This study is the first concrete evidence of the varicella incidence decline after the implementation of a single dose application program in Argentina.

Trends in varicella and mumps vaccination rates in children under 3 years of age in a tertiary children's hospital in Japan

BACKGROUND

In Japan, the voluntary vaccination rate is not known accurately. Although two doses of the measles and rubella vaccines have been part of the universal vaccine program since 2006, the varicella vaccine was added in October 2014 while the mumps vaccine still remains voluntary. The aim of this study was to evaluate trends in the live measles, rubella, varicella and mumps vaccination rates in Japan.

METHODS

This retrospective cohort study was conducted at Tokyo Metropolitan Children's Medical Center between October 2012 and December 2016. Patients aged 1-2 years who were admitted to the Department of General Pediatrics were enrolled. The trend in the vaccination rate against measles, rubella, varicella, and mumps was examined.

RESULTS

The measles and rubella vaccination rate was 80-90%. The varicella vaccination rate in the second quarter of 2012, the third quarter of 2014, and the fourth quarter of 2016 was 34.6%, 67.1%, and 80.7%, respectively. The mumps vaccination rate in the second quarter of 2012, the third quarter of 2014, and the fourth quarter of 2016 was 27.6%, 59.5%, and 61.8%, respectively.

CONCLUSIONS

The varicella and mumps vaccination rate improved until 2014 despite the fact that they were voluntary vaccinations. After varicella vaccination was added to the universal vaccination program, the varicella vaccination rate continued to improve. The mumps vaccination, which was not included, failed to improve, suggesting that the universal vaccination program contributed to increasing the uptake of the vaccines it includes.

Cost-effectiveness analysis of universal varicella vaccination in Turkey using a dynamic transmission model

BACKGROUND

In 2013, Turkey introduced one-dose universal varicella vaccination (UVV) at 12 months of age. Inclusion of a second dose is being considered.

METHODS

We developed a dynamic transmission model to evaluate three vaccination strategies: single dose at 12 months (1D) or second dose at either 18 months (2D-short) or 6 years of age (2D-long). Costs and utilization were age-stratified and separated into inpatient and outpatient costs for varicella and herpes zoster (HZ). We ran the model including and excluding HZ-related costs and impact of exogenous boosting.

RESULTS

Five years post-introduction of UVV (1D), the projected varicella incidence rate decreases from 1,674 cases pre-vaccine to 80 cases/100,000 person-years. By 25 years, varicella incidence equilibrates at 39, 12, and 16 cases/100,000 person-years for 1D, 2D-short, and 2D-long strategies, respectively, using a highly effective vaccine. With or without including exogenous boosting impact and/or HZ-related costs and health benefits, the 1D strategy is least costly, but 2-dose strategies are cost-effective considering a willingness-to-pay threshold equivalent to the gross domestic product. The model predicted a modest increase in HZ burden during the first 20-30 years, after which time HZ incidence equilibrates at a lower rate than pre-vaccine.

CONCLUSIONS

Our findings support adding a second varicella vaccine dose in Turkey, as doing so is highly cost-effective across a wide range of assumptions regarding the burden associated with varicella and HZ disease.

Trends in varicella and herpes zoster epidemiology before and after the implementation of universal one-dose varicella vaccination over one decade in South Korea, 2003-2015

Background: In South Korea, the one-dose varicella vaccine was included in the National Immunization Program for children aged 12-15 months in 2005, and the vaccine coverage reached >95%. The impact of varicella vaccination on varicella and herpes zoster (HZ) was investigated, accounting for demographic changes over time.Methods: We calculated the crude and age-sex standardized incidence rates (IRs) and age-specific IRs of varicella and HZ from 2003 to 2015, using the National Health Information Database including approximately 50 million Koreans. The annual incidence rate ratios (IRRs) were calculated using a negative binomial regression analysis, adjusting for age and sex.Results: The crude varicella IR steadily declined by 67%, from 5.70/1000 to 1.87/1000 person years (IRR per year: 0.91; 95% CI 0.89-0.93), but the adjusted IRs showed a significant decline only during 2010-2015 (adjusted IRR per year: 0.90; 95% CI 0.88-0.93). The greatest decline was found in children ≤4 years of age, whereas the IR increased until 2011 and then declined afterward in children aged 5-9 years, who represented the highest incidence age group in 2013-2015. The crude HZ IR increased from 2.67/1000 to 9.80/1000 person years (IRR per year: 1.12; 95% CI 1.10-1.15), and the adjusted IR also followed the same trend. A similar increasing trend was observed before and after universal vaccination.Conclusions: One-dose varicella vaccination was moderately effective in preventing varicella, but this strategy was insufficient to interrupt varicella transmission in children. Furthermore, the HZ incidence dramatically increased over this decade. The current vaccination strategy against varicella-zoster disease should be reconsidered.

Implementing Universal Varicella Vaccination in Europe: The Path Forward

Varicella is a common vaccine-preventable disease that usually presents as a mild disorder but can lead to severe complications. Before the implementation of universal varicella vaccination (UVV) in some European countries, the burden of varicella disease was broadly similar across the region. Despite this, countries adopted heterogeneous varicella vaccination strategies. UVV is currently recommended in 12 European countries. Known barriers to UVV implementation in Europe include (1) a perceived low disease burden and low public health priority; (2) cost-effectiveness and funding availability; (3) concerns related to a shift in varicella disease and incidence of herpes zoster and (4) safety concerns related to measles, mumps, rubella and varicella-associated febrile seizures after the first dose. Countries that implemented UVV experienced decreases in varicella incidence, hospitalizations and complications, showing overall beneficial impact. Alternative strategies targeting susceptible individuals at higher risk of complications have been less effective. This article discusses ways to overcome the barriers to move varicella forward as a truly vaccine preventable disease.

Cross-sectional study on hospitalizations related to herpes zoster in an Italian region, 2008-2016

INTRODUCTION

To assess the burden of herpes zoster (HZ) by analyzing HZ-related hospital admissions.

METHODS

We conducted a population-based descriptive cross-sectional study on all hospitalizations for HZ among the resident population admitted to all public and accredited private hospitals in the Veneto Region (north-east Italy) during the years 2008-2016. HZ hospitalizations were identified from the International Classification of Diseases codes in the hospital discharge records.

RESULTS

During the period considered, we identified 3566 HZ-associated admissions, 194 (5.4%) of which were readmissions within 30 days. A complicated HZ diagnosis was mentioned for 44.4% of the patients admitted once and for 65.9% of those admitted twice. In the sample as a whole, 27.0% of patients had at least one comorbidity. Overall, our analysis revealed a gradual increase in hospitalizations with age for both genders, reaching a hospitalization rate for the population over 80 years old of 51.2 × 100,000 for males and 52.8 × 100,000 for females. The average hospitalization rate for HZ-related conditions during the years 2008-2016 was 7.7 per 100,000 population. Postherpetic neuralgia was diagnosed in 8.2% of hospitalizations, with no difference between the genders. The estimated overall cost of HZ-related conditions was approximately €2.7 million a year.

CONCLUSIONS

This study suggests that the burden of HZ and its impact on quality of life are of critical relevance to public health decision-making.

Global impact of varicella vaccination programs

Although varicella is usually a mild and self-limited disease, complications can occur. In 1998, the World Health Organization recommended varicella vaccination for countries where the disease has a significant public health burden. Nonetheless, concerns about a shift in the disease to older groups, an increase in herpes zoster in the elderly and cost-effectiveness led many countries to postpone universal varicella vaccine introduction. In this review, we summarize the accumulating evidence, available mostly from high and middle-income countries supporting a high impact of universal vaccination in reductions of the incidence of the disease and hospitalizations and its cost-effectiveness. We have also observed the effect of herd immunity and noted that there is no definitive and consistent association between vaccination and the increase in herpes zoster incidence in the elderly.

The impact of demographic changes, exogenous boosting and new vaccination policies on varicella and herpes zoster in Italy: a modelling and cost-effectiveness study

BACKGROUND

The present study aims to evaluate the cost-effectiveness of the newly introduced varicella and herpes zoster (HZ) vaccination programmes in Italy. The appropriateness of the introduction of the varicella vaccine is highly debated because of concerns about the consequences on HZ epidemiology and the expected increase in the number of severe cases in case of suboptimal coverage levels.

METHODS

We performed a cost-utility analysis based on a stochastic individual-based model that considers realistic demographic processes and two different underlying mechanisms of exogenous boosting (temporary and progressive immunity). Routine varicella vaccination is given with a two-dose schedule (15 months, 5-6 years). The HZ vaccine is offered to the elderly (65 years), either alone or in combination with an initial catch-up campaign (66-75 years). The main outcome measures are averted cases and deaths, costs per quality-adjusted life years gained, incremental cost-effectiveness ratios, and net monetary benefits associated with the different vaccination policies.

RESULTS

Demographic processes have contributed to shaping varicella and HZ epidemiology over the years, decreasing varicella circulation and increasing the incidence of HZ. The recent introduction of varicella vaccination in Italy is expected to produce an enduring reduction in varicella incidence and, indirectly, a further increase of HZ incidence in the first decades, followed by a significant reduction in the long term. However, the concurrent introduction of routine HZ vaccination at 65 years of age is expected to mitigate this increase and, in the longer run, to reduce HZ burden to its minimum. From an economic perspective, all the considered policies are cost-effective, with the exception of varicella vaccination alone when considering a time horizon of 50 years. These results are robust to parameter uncertainties, to the two different hypotheses on the mechanism driving exogenous boosting, and to different demographic projection scenarios.

CONCLUSIONS

The recent introduction of a combined varicella and HZ vaccination programme in Italy will produce significant reductions in the burden of both diseases and is found to be a cost-effective policy. This programme will counterbalance the increasing trend of zoster incidence purely due to demographic processes.

Impact of vaccination programs against measles, varicella and meningococcus C in Italy and in Tuscany and public health policies in the last decades

The World Health Organization (WHO) has established specific targets for control, elimination or eradication of some vaccine preventable infectious diseases, which were periodically updated. In Italy, WHO recommendations have been endorsed and implemented over time, through the national and regional health prevention plans. The aim of the study was to assess the impact of the immunization practices against measles, varicella and Neisseria meningitidis type C (Men C) in Italy and in Tuscany Region, during the last decades, by analyzing national and regional surveillance databases. Benefits of vaccination strategies were discussed from different points of view (clinical, epidemiological, economic, ethical, social and communicative). The implementation of measles, varicella and Men C vaccination, caused a considerable decrease of incidence rates over the years in Italy and in Tuscany too. However, in the last years, notifications of measles and Men C cases in subjects not targeted by immunization campaigns, in Italy and in Tuscany, are a cause for concern for public health and for the achievement of the elimination goals. Achieving and maintaining high vaccine coverage guarantees a decrease in the incidence of serious diseases and their clinical and economic consequences, but it is necessary to strengthen surveillance system of infectious diseases in order to monitor epidemiological trends. Moreover, outreach campaigns are necessary to raise awareness in the general population and create the culture of prevention with the same nationwide health goals for all.

Epidemiology, management and outcome of varicella in pregnancy: a 20-year experience at the Tuscany Reference Centre for Infectious Diseases in Pregnancy

Data from 215 pregnant women exposed to varicella and 276 with varicella observed at the Tuscany Reference Center for Infectious Diseases in Pregnancy, Florence, Italy, in the period 1997-2016 were retrospectively collected. The risk of developing varicella was lower in exposed women who received varicella zoster immunoglobulin compared with those who did not receive it [42% (21 of 50) vs 72% (13 of 18); p = 0.0263]. Typical congenital varicella syndrome was observed in 1.56% of fetuses/neonates born from pregnant women with varicella.

The changing epidemiology of varicella and herpes zoster in Hong Kong before universal varicella vaccination in 2014

In Hong Kong, universal varicella vaccination started in July 2014. Before this, children could receive varicella vaccine via the private market. We analysed the epidemiology of varicella and zoster before universal vaccination. We estimated varicella vaccination coverage through surveys in preschool children. We estimated the burden of varicella and zoster with varicella notifications from 1999/00 to 2013/14, Accident and Emergency Department (A&E) attendance and inpatient admissions to public hospitals from 2004/05 to 2013/14. We fitted a catalytic model to serological data on antibodies against varicella-zoster virus to estimate the force of infection. We found that varicella vaccination coverage gradually increased to about 50% before programme inception. In children younger than 5 years, the annual rate of varicella notifications, varicella admission and zoster A&E attendance generally declined. The annual notification, A&E attendance and hospitalisation rate of varicella and zoster generally increased for individuals between 10 and 59 years old. Varicella serology indicated an age shift during the study period towards a higher proportion of infections in slightly older individuals, but the change was most notable before vaccine licensure. In conclusion, we observed a shift in the burden of varicella to slightly older age groups with a corresponding increase in incidence but it cannot necessarily be attributed to private market vaccine coverage alone. Increasing varicella vaccination uptake in the private market might affect varicella transmission and epidemiology, but not to the level of interrupting transmission.

Early impact of universal varicella vaccination on childhood varicella and herpes zoster hospitalizations in Brazil

INTRODUCTION

The Brazilian childhood National Immunization Program (NIP) introduced live and attenuated varicella vaccination in a single dose, combined as tetraviral vaccine, at 15 months of age in the whole country, during September to December of 2013. The aim of this study was to report trends in incidence of childhood hospital admissions related to varicella and zoster in Brazil from 2003 to 2016, including the first three years after vaccine introduction.

METHODS

The number and incidence of hospital admission in patients aged less than 20 years in Brazilian public health system with an admission diagnosis of varicella and zoster from 2003 to 2016 were analyzed and pre (2003-2013) and post-vaccination periods (2014-2016) were compared. The data were obtained from DATASUS, a Brazilian government's open-access public health database system, and analyzed adjusting for secular trend and seasonality if a statistically significant change was found.

RESULTS

During the study period, 69,791 admissions due to varicella and herpes zoster occurred in the children younger than 20 years. After adjusting for seasonality, the incidence of hospitalizations decreased from 27.33 to 14.33 per 100000 per year, which corresponds to a reduction of 47.6% (95% confidence interval 18.19-77.04%, p < 0.001) in the vaccinated age group (1-4 years) in 2014-2016 compared to pre-vaccination period. The changes were not significant in the unvaccinated age groups.

CONCLUSION

The hospitalizations due to varicella and herpes zoster were decreased by half early after the introduction of a single dose of tetraviral vaccine in NIP in the vaccinated children. Further studies may assess duration and intensity of this effect, as well as the indirect effect in the unvaccinated age groups.

A postmarket safety comparison of 2 vaccination strategies for measles, mumps, rubella and varicella in Italy

It is strategically important to monitor the safety profile of vaccination schedules in order to achieve and maintain high levels of coverage. We analyzed the cohort of individuals actively invited for measles, mumps, rubella and varicella (MMRV) vaccination in the Veneto region (north-east Italy) from 8/1/2013 to 7/31/2014, assessing the onset of adverse events (AE) relating to 2 different vaccination strategies for MMRV (MMR+V vs MMRV). During the vaccination session at 14 months old, parents were given a form for recording local and systemic reactions to vaccinations for 4 weeks afterwards. Overall, 12,288 forms were returned, and 84.6% of them were included in this analysis (5,130 relating to MMR+V and 5,265 to MMRV); 37.3% of the sample reported no AEs, with no difference between the 2 groups. Local reactions were more common in the MMR+V group (9.6% vs 2.9%; RR 3.33; 95% CI 2.79-3.98), while there was no difference in general reactions between the 2 groups (50% MMR+V vs 52% MMRV). The events most often reported were "fever <39.5°C," which was more frequently associated with the MMRV strategy (p<0.001), and "skin blotches and marks," which occurred more often in the MMR+V group (p<0.001). Reports of "fever ≥39.5°C" were equally distributed between the 2 groups. Sixteen cases of febrile seizures were reported (0.14% in the MMR+V group and 0.17% in the MMRV group). Similar safety profiles were identified for the 2 vaccination strategies. Although the method used to record reactions to vaccination demanded considerable resources, it enabled important information to be collected on parents' perception of the AEs occurring in response to their child's vaccination.

Temporal trends in herpes zoster-related hospitalizations in Italy, 2001-2013: differences between regions that have or have not implemented varicella vaccination

BACKGROUND

Herpes zoster (HZ) has a relevant impact on the population in terms of incidence and complications.

AIMS

The aim of this study was to estimate the HZ-related hospitalization rates in Italy in the period 2001-2013, and to evaluate the trend of hospitalizations in the course of time pointing out any differences between regions that have or have not introduced universal childhood varicella immunization (UVI).

METHODS

A retrospective analysis was conducted on hospital discharge records contained in the national database of the Ministry of Health for the period January 2001-December 2013. The comparison of hospitalization rates of "pilot" versus "not pilot" regions was performed taking into account as "pilot" regions the three that first introduced UVI (Sicily, Veneto, and Apulia). The average annual percentage change in hospitalization rates was used to highlight any significant change in time trends.

RESULTS

In the period 2001-2013, 93,808 HZ-related hospitalizations were registered altogether. Complicated HZ was diagnosed in 53.2% of cases; a relevant part (32.5%) of hospitalizations involved subjects with at least one co-morbidity. In the three Italian "pilot" regions, a greater decrease of HZ-related hospitalization rates occurred in comparison to other regions.

DISCUSSION

A good understanding of the epidemiology of HZ disease is required to assess the overall impact of the varicella immunization programs and to establish the most appropriate health strategies against HZ.

CONCLUSIONS

The data obtained confirm the epidemiological impact of HZ and its complications and the need of a preventive approach.

Varicella vaccination - the global experience

INTRODUCTION

Varicella, although a frequently benign childhood disease, nevertheless represents a considerable health burden. WHO recommends including varicella vaccines in universal routine vaccination programs, and maintaining coverage >80%. Many countries have successfully introduced varicella vaccination and have benefited from lower disease burden, but many others have not adopted the vaccine. Reasons include cost commitment for a 'mild childhood disease' or concerns that vaccination will shift varicella to older age groups or increase herpes zoster incidence. Areas covered: This literature review summarizes the effectiveness and epidemiological impact of varicella immunization programs. Expert commentary: Varicella vaccines are immunogenic with acceptable safety profiles. One and two dose schedules are highly effective against varicella and large reductions in disease incidence, particularly moderate-severe disease, have been widely reported. There is currently no evidence to suggest that the introduction of varicella vaccination results in a shift of varicella disease burden to older age groups. Although epidemiological studies have shown an increased incidence of herpes zoster since the vaccines were launched, there are many other contributing factors, and indeed, this secular trend was evident before their introduction. In conclusion, varicella vaccination easily fits into existing immunization programs and significantly reduces the often underestimated burden of varicella.

Preparing to introduce the varicella vaccine into the Italian immunisation programme: varicella-related hospitalisations in Tuscany, 2004-2012

A universal immunisation programme against varicella in the form of the measles-mumps-rubella-varicella (MMRV) vaccine for toddlers aged 13-15 months was introduced in Tuscany in July 2008. An assessment of the impact of this programme on varicella-related hospitalisations 4 years after its introduction could further support its adoption at a national level. The hospitalisation data were analysed in two periods: pre-vaccination (2004-2007) and vaccination period (2009-2012). The high coverage of the vaccines (84% in 2012) resulted in a significant decline in notifications, from 33,114 (2004-2007) to 13,184 cases (2009-2012), and also of hospitalisations, from 584 (pre-vaccination period) to 325 (vaccination period). The hospitalisation rate was 4.1 per 100,000 (95% confidence intervals (CI): 3.4-4.7) before the introduction of vaccination, which dropped to 2.2 per 100,000 (95% CI: 1.7-2.7) in the vaccination period (hospitalisation risk ratios: 0.54; 95% CI:  0.472-0.619). The reduction was most significant in the youngest age groups. The introduction of universal vaccination has already led to a significant decline in hospitalisations due to varicella after just 4 years of implementation. Hospitalisation rates fell noticeably among younger individuals involved in the vaccination programme. The decrease in hospitalisation rate in the older age groups suggests a possible indirect protection.

Knowledge, attitudes, and behaviors of parents towards varicella and its vaccination

BACKGROUND

The aims of this cross-sectional survey were to examine the knowledge, the attitudes, and the behavior regarding the varicella infection and its vaccination and to get insight into their determinants among parents of children in Italy.

METHODS

From May to June 2015 in the geographic area of Naples (Italy) a random sample of 675 parents of children aged 4-7 years received a self-administered anonymous questionnaire about socio-demographic characteristics, knowledge, attitudes, and behaviors towards varicella and its vaccination.

RESULTS

A total of 414 parents responded to the questionnaire, for a response rate of 61.3%. A history of varicella was reported in 163 children (39.6%). Only 26.6% parents knew that the vaccine was available and the number of doses and this knowledge was significantly higher in those who had a university degree, in those who had received information on the vaccination from a health care provider, and in those who had vaccinated their child. The perceived utility towards vaccination had a mean value of 5.7. The positive attitude towards the utility of the vaccination was higher in parents with a level of education not higher than middle school, in those who had vaccinated their child, in those who considered the varicella a dangerous disease, and in those who had received information from a health care provider. More than one-third had vaccinated their child. Immunization was more frequent in parents who had knowledge about the vaccination, who beliefs that the immunization was useful, who believed that the disease was not dangerous, and who had not a history of varicella among their children.

CONCLUSIONS

Educational programs are needed among parents as support to improve knowledge about vaccination and immunization coverage.

Has VZV epidemiology changed in Italy? Results of a seroprevalence study

The aim of the study was to evaluate if and how varicella prevalence has changed in Italy. In particular a seroprevalence study was performed, comparing it to similar surveys conducted in pre-immunization era. During 2013-2014, sera obtained from blood samples taken for diagnostic purposes or routine investigations were collected in collaboration with at least one laboratory/center for each region, following the approval of the Ethics Committee. Data were stratified by sex and age. All samples were processed in a national reference laboratory by an immunoassay with high sensitivity and specificity. Statutory notifications, national hospital discharge database and mortality data related to VZV infection were analyzed as well. A total of 3707 sera were collected and tested. In the studied period both incidence and hospitalization rates decreased and about 5 deaths per year have been registered. The seroprevalence decreased in the first year of life in subjects passively protected by their mother, followed by an increase in the following age classes. The overall antibody prevalence was 84%. The comparison with surveys conducted with the same methodology in 1996-1997 and 2003-2004 showed significant differences in age groups 1-19 y. The study confirms that in Italy VZV infection typically occurs in children. The impact of varicella on Italian population is changing. The comparison between studies performed in different periods shows a significant increase of seropositivity in age class 1 - 4 years, expression of vaccine interventions already adopted in some regions.

Coverage, efficacy or dosing interval: which factor predominantly influences the impact of routine childhood vaccination for the prevention of varicella? A model-based study for Italy

BACKGROUND

Varicella is a highly infectious disease with a significant public health and economic burden, which can be prevented with childhood routine varicella vaccination. Vaccination strategies differ by country. Some factors are known to play an important role (number of doses, coverage, dosing interval, efficacy and catch-up programmes), however, their relative impact on the reduction of varicella in the population remains unclear. This paper aims to help policy makers prioritise the critical factors to achieve the most successful vaccination programme with the available budget.

METHODS

Scenarios assessed the impact of different vaccination strategies on reduction of varicella disease in the population. A dynamic transmission model was used and adapted to fit Italian demographics and population mixing patterns. Inputs included coverage, number of doses, dosing intervals, first-dose efficacy and availability of catch-up programmes, based on strategies currently used or likely to be used in different countries. The time horizon was 30 years.

RESULTS

Both one- and two-dose routine varicella vaccination strategies prevented a comparable number of varicella cases with complications, but two-doses provided broader protection due to prevention of a higher number of milder varicella cases. A catch-up programme in susceptible adolescents aged 10-14 years old reduced varicella cases by 27-43 % in older children, which are often more severe than in younger children. Coverage, for all strategies, sustained at high levels achieved the largest reduction in varicella. In general, a 20 % increase in coverage resulted in a further 27-31 % reduction in varicella cases. When high coverage is reached, the impact of dosing interval and first-dose vaccine efficacy had a relatively lower impact on disease prevention in the population. Compared to the long (11 years) dosing interval, the short (5 months) and medium (5 years) interval schedules reduced varicella cases by a further 5-13 % and 2-5 %, respectively. Similarly, a 10 % increase in first-dose efficacy (from 65 to 75 % efficacy) prevented 2-5 % more varicella cases, suggesting it is the least influential factor when considering routine varicella vaccination.

CONCLUSIONS

Vaccination strategies can be implemented differently in each country depending on their needs, infrastructure and healthcare budget. However, ensuring high coverage remains the critical success factor for significant prevention of varicella when introducing varicella vaccination in the national immunisation programme.

Global Varicella Vaccine Effectiveness: A Meta-analysis

CONTEXT

Several varicella vaccines are available worldwide. Countries with a varicella vaccination program use 1- or 2-dose schedules.

OBJECTIVE

We examined postlicensure estimates of varicella vaccine effectiveness (VE) among healthy children.

DATA SOURCES

Systematic review and descriptive and meta-analysis of Medline, Embase, Cochrane libraries, and CINAHL databases for reports published during 1995-2014.

STUDY SELECTION

Publications that reported original data on dose-specific varicella VE among immunocompetent children.

DATA EXTRACTION

We used random effects meta-analysis models to obtain pooled one dose VE estimates by disease severity (all varicella and moderate/severe varicella). Within each severity category, we assessed pooled VE by vaccine and by study design. We used descriptive statistics to summarize 1-dose VE against severe disease. For 2-dose VE, we calculated pooled estimates against all varicella and by study design.

RESULTS

The pooled 1-dose VE was 81% (95% confidence interval [CI]: 78%-84%) against all varicella and 98% (95% CI: 97%-99%) against moderate/severe varicella with no significant association between VE and vaccine type or study design (P > .1). For 1 dose, median VE for prevention of severe disease was 100% (mean = 99.4%). The pooled 2-dose VE against all varicella was 92% (95% CI: 88%-95%), with similar estimates by study design.

LIMITATIONS

VE was assessed primarily during outbreak investigations and using clinically diagnosed varicella.

CONCLUSIONS

One dose of varicella vaccine was moderately effective in preventing all varicella and highly effective in preventing moderate/severe varicella, with no differences by vaccine. The second dose adds improved protection against all varicella.

How can the results of Health Technology Assessment (HTA) evaluations applied to vaccinations be communicated to decision-makers and stakeholders? The ISPOR Rome Chapter Project

HTA is considered the most comprehensive and transparent method of supporting decision-makers in their choices in Public Health. HTA on vaccines is being performed by many experts. However, they often present their studies to colleagues, but not to decisionmakers, who should be the main target and current users. It is therefore crucial to improve the transfer of scientific data to decision- makers and all stakeholders. The aims of the present project are: 1) to set up a team of experts to collect economic evaluations and HTA studies on vaccines and assess their actual use in decision-making processes; 2) to constitute regional working groups in order to identify the critical aspects of the communication process and identify the most appropriate method of data transfer. Systematic reviews of economic evaluations and HTA on vaccines and their actual use in decision-making will be used to draw up the basic documents for discussion by the 3 regional working boards. The working groups will discuss the current scientific evidence and communication methods and will try to implement a model of technology assessment with well-defined and objective criteria, in order to better fit pharmaco-economic and HTA methods to the field of vaccinations. Improving the transfer of HTA results to stakeholders, particularly decision-makers, will enable decisions to be taken on the basis of scientific evidence, and appropriate, sustainable actions to be undertaken.