Varicella Immunization Research Articles

Incomplete Immunity for Varicella and Measles in Pediatric Organ Transplant Candidates. Real World Experience From an Infectious Diseases Pre-Transplantation Clinic.

Vaccinating pediatric solid organ transplant candidates against measles and varicella is crucial due to the risk of severe disease in immunosuppressed recipients and general avoidance of live virus vaccines post-transplantation. The world saw a resurgence of measles starting 2012 prompting the American Society of Transplantation in 2015 to release guidelines on recognition, prevention, and post-exposure prophylaxis of this disease in solid transplant recipients. This study aims to assess the extent of incomplete immunity to these viruses in candidates and the approach to immunity optimization during a period of heightened awareness. A cross-sectional study from 2012 to 2016 at Cleveland Clinic Children's included pediatric solid organ transplant candidates. Data on vaccination history, serology, and demographics were collected. Incomplete immunity was defined by incomplete vaccination or seronegativity. Among 91 candidates, 54.9% had complete varicella vaccination. Serological varicella immunity among patients tested varied by age: < 7 years, 50.0% positive in patients with complete schedules, none in the incomplete; ≥ 7 years, 50.0% positive in patients with complete schedules, 65.5% in the incomplete. For measles, 69.2% had complete vaccination, with immunity varying by age among those tested: < 7 years, 84.6% positive in patients with complete schedules, 42.9% in the incomplete; ≥ 7 years, 81.0% with complete, 62.5% with incomplete. Only 31.1% of those who qualified for a varicella additional dose and 28% who qualified for an additional measles dose received it, respectively. Incomplete immunity to varicella and measles was prevalent in pediatric solid organ transplant candidates at our center during the study period. Despite an increase in global measles activity, our efforts to optimize immunity through additional vaccine doses were only partially successful. Future research should focus on addressing strategies and understanding barriers to ensure timely vaccination for this vulnerable population prior to transplant, especially during periods of increased viral activity.

Population immunity to varicella in Canada: A Canadian Immunization Research Network (CIRN) study.

The incidence of varicella in Canada has decreased by almost 99% since vaccination was introduced. However, variation in the timing and eligibility of vaccination programs across the country has resulted in some cohorts being under-vaccinated and therefore potentially susceptible to infection. We used nationally representative specimens from the Biobank of Statistics Canada's Canadian Health Measures Survey (CHMS) as well as residual specimens from Ontario collected between 2009-2014 to estimate population immunity across age-groups and geography, and identify any groups at increased risk of varicella infection. The weighted proportion of specimens with antibody levels above the threshold of protection was 93.6% (95% CI: 92.4, 95.0). Protection was lowest among those aged 3-5 years (54.3%; 95% CI: 47.3, 61.4), but increased with age. Individuals born outside Canada had more than twice the odds of varicella susceptibility than those born in Canada (aOR: 2.7; 95% CI: 1.4, 5.0; p = 0.004). There were no differences by sex or geography within Canada, and there were no statistically significant differences when Ontario CHMS sera were compared to Ontario residual sera, apart from in participants aged 12-19 year age-group, for whom the CHMS estimate (91.2%; 95% CI: 86.7, 95.7) was significantly higher (p = 0.03) than that from residual specimens (85.9%, 95% CI: 81.1, 90.8). Varicella immunity in Canada is changing. Children appear to have low population immunity, placing them at greater risk of infection and at increased risk of severe disease as they age. Our results underscore the importance of performing periodic serosurveys to monitor further population immunity changes as the proportion of vaccine-eligible birth-cohorts increases, and to continually assess the risk of outbreaks.

Cost-Effectiveness of Varicella Vaccination for 1–4-Year-Olds in Shanghai, China

IntroductionVaricella has not yet been included in the National Immunization Program (NIP) in China, and varicella vaccination strategies vary by region. To determine the optimal varicella vaccination strategy in Shanghai, China, the cost-effectiveness and five-year costs of five immunization scenarios were analyzed. MethodsA static decision tree-Markov model was developed in 2022 to assess the cost-effectiveness and five-year costs of voluntary and routine varicella vaccination programs in the 2019 birth cohort in Shanghai from a societal perspective. Parameters were collected in 2022 from the varicella surveillance system, a questionnaire survey of 414 guardians of patients with childhood varicella, and semi-structured interviews with 20 experts on varicella outbreaks from different institutions in Shanghai. The outcomes included varicella cases avoided, quality-adjusted life year (QALY) loss, and incremental costs per QALY (ICER). The five-year costs were compared with local medical expenditures. ResultsAmong the five scenarios, one dose of routine varicella vaccination was the most cost-saving (USD 70.2) and cost-effective (Dominant) with a five-year immunization expenditure of USD 9.9 million. Two doses of routine varicella vaccination had the highest QALY (29.9), and its ICER (USD 791.9/QALY) was below the willingness-to-pay threshold (USD 5,203-23,767/QALY). The five-year immunization expenditure was USD 19.8 million. The effectiveness and price of vaccines, vaccination coverage, and per capita income are the four main factors that affect ICERs. ConclusionsIn Shanghai, the two doses of routine varicella vaccination strategy for 1- and 4-year-olds with a 95% coverage rate was found to be the optimal varicella immunization strategy.

Herpes Zoster and Post-Herpetic Neuralgia-Diagnosis, Treatment, and Vaccination Strategies.

Herpes zoster is caused by the reactivation of latent varicella infection within the sensory ganglia, caused by the varicella-zoster virus (VZV). The disease is classically characterized by a painful unilateral vesicular eruption. Complications of the disease include herpes zoster ophthalmicus, Ramsay Hunt syndrome, acute retinal necrosis, and post-herpetic neuralgia. In this paper, we discuss the epidemiology, pathogenesis, clinical features, diagnosis, management, and vaccination strategies of herpes zoster and post-herpetic neuralgia. This paper was developed with input from specialists from Singapore's public sectors-dermatologists, family physicians, and infectious diseases specialists. The diagnosis of herpes zoster is clinical and can be aided with laboratory investigations. Early initiation of antivirals, within 72 h of onset, can reduce the severity and duration of the condition and decrease the intensity of pain. In patients with a high risk of post-herpetic neuralgia, early initiation of anticonvulsants or tricyclic antidepressants can be considered. Herpes zoster is highly preventable, with the advent of the recombinant zoster vaccine (RZV) providing an overall vaccine efficacy of 97.2%. Procedures such as epidural blocks and subcutaneous or intracutaneous injections of local anesthetics and steroids can be considered for patients with a high risk of post-herpetic neuralgia to reduce its incidence. This article serves as a guideline for clinicians in the diagnosis, investigations, management, and prevention of herpes zoster. With the majority of adults in Singapore currently at risk of developing herpes zoster due to varicella immunization being only introduced in 2020, it is important for clinicians to recognize and manage herpes zoster appropriately.

Adverse events following Measles-Mumps-Rubella and varicella immunization: A safety profile analysis and comparison of different vaccination schedules based on the Italian Pharmacovigilance Network in the Veneto Region

ObjectiveThe vaccines for measles, mumps, rubella and varicella (MMR and V) have been mandatory in Italy since 2017. Two different vaccination strategies are suggested for the first dose: trivalent MMR and a separate V vaccine or the tetravalent MMRV vaccine. Our aim is to compare the safety profile of MMRV and MMR-V vaccines through the passive adverse event reporting system in the Veneto region and to perform a case-by-case review of a few conditions of interest (febrile and afebrile seizures, ataxia, encephalitis, Guillain-Barré Syndrome, thrombocytopenia, neutropenia and Henoch-Schönlein Purpura). Age and sex differences were also explored. MethodsWe identified all reports following MMRV or MMR-V vaccination in the Veneto Region and received into the National Pharmacovigilance Network between 2007 and April 30, 2022. Results9,510 reports were retrieved, of which 5,662 (59.5 %) were related to MMRV and 3,848 (40.5 %) to MMR-V. No safety signals were detected supporting the evidence that MMRV and MMR-V vaccinations have a good safety profile. The reporting rate (RR) for serious events between 2007 and 2022 resulted in 13.67 per 10,000 administered doses for MMRV and 10.90 for MMR-V. ConclusionPassive surveillance data show a significantly higher rate of serious events for males 0–2 years old, both overall and stratified per vaccination strategy. Further studies are needed to confirm this observation. The analyses suggest that retrieved differences do not have a significant impact on the overall safety of both formulations.

Trends in age-specific varicella incidences following the introduction of the general recommendation for varicella immunization in Germany, 2006–2022

BackgroundIn Germany, general childhood varicella vaccination has been recommended since 2004. A feared effect of low vaccination coverage is a possible shift in incidence from children to teenagers and young adults who are at higher risk of severe outcomes. If true, this shift would possibly necessitate changes to the national immunization strategy.We aimed to evaluate the effects of the general vaccination recommendation on age-specific varicella incidences in Germany in general and examine specifically whether a shift from children to teenagers (15 to 19 years) has occurred.MethodsTrends in age-specific incidences were evaluated using triangulation with the following datasets: national mandatory notification data (N) (2014–2022), billing data of the statutory health insurance associations (I) (2009–2017) and data from a doctor's sentinel system (S) (2006–2017). Similar clinical case definitions were used in N and S, while I used ICD-10-codes. Age groups were stratified as available in all three systems. Incidences per year were calculated based on the total population (N), the number of statutory health insured (I), and extrapolated from S to the total population.ResultsDuring all years of observation, age-specific incidences have dropped significantly across all age-groups for S und I. The age groups (under 10 years) with initially highest incidences were the ones with the strongest reductions (under 1 year: -90%, 1–4 years: -95.5%, 5–9 years: -89.2% for S; -67.7%, -78%, -79.3% for I). A single 53.1% increase in the low incidence in S among 15–19-year olds observed in 2017 compared to 2016 could not be confirmed in N or I. Increases in incidences during the first two years of N are probably due to improved notification behaviour over these years. In 2019, all age-specific incidences increased (N), with 15 to 19-year olds showing the highest relative increase (28.2%).ConclusionsSince the introduction of the general vaccine recommendation against varicella, incidences across all age-groups have declined significantly. Available data indicate no evidence for a shift in disease incidence to older age groups. Every incidence increase beyond childhood age should however be followed up closely. So far, children and adolescents have both benefitted from the current vaccination strategy.

Impact of Varicella Immunization and Public Health and Social Measures on Varicella Incidence: Insights from Surveillance Data in Shanghai, 2013-2022.

To evaluate the impact of a two-dose VarV program on varicella incidence among the whole population, considering the influence of public health and social measures (PHSMs), we extracted surveillance data on varicella cases during 2013-2022 in Minhang, Shanghai. Then, we estimated the incidence trend of varicella through interrupted time-series analyses and quantified the impact of the immunization program and PHSMs using Serfling regression. We also explored the associations between PHSMs and varicella cases. The implementation of the two-dose VarV strategy was followed by a significant decrease in varicella incidence (-1.84% per month). After one year of the program, varicella incidence was estimated at a 45.25% reduction, which was higher in children (59.12% and 54.09%) than in adults (19.49%). The decrease attributed to PHSMs was 31.26% during 2020-2022, and school closing was identified as the most relevant PHSM (b = -8.03 cases, r = -0.67 with a 1-week lag). These findings indicate that the two-dose immunization program has more effectively reduced the varicella incidence compared with the one-dose vaccine, and interventions like school closings are also encouraged to serve as supplementary measures to prevent varicella epidemics.

630. A Single-Center 10-Year Analysis of Immunizations in Heart Transplant Recipients

Abstract Background Vaccine-preventable diseases pose a risk towards heart transplant recipients on lifelong immunosuppression. Immunization rates are low (30-80%) in solid organ transplants. The aim of this study was to examine the vaccination rates in our hospital’s heart transplant recipients with a goal to expose deficiencies and formulate strategies to increase vaccination in this population. Methods This study is a single-center retrospective chart review of patients aged 18 or older who received a heart transplant between January 1, 2012 and March 31, 2022 at our institution in Temple, Texas. We documented vaccination status or seropositivity prior to or after transplant, as recommended by the American Society of Transplantation (AST) for influenza, hepatitis B, hepatitis A, measles, mumps, and rubella (MMR), 23-valent pneumococcal polysaccharide (PPSV23), 13-valent pneumococcal conjugate (PCV13), tetanus, diphtheria, and acellular pertussis (Tdap), varicella, zoster, and COVID-19 immunizations. We evaluated the association with an Infectious Disease (ID) consult. Odds ratios (OR) were calculated with 95% confidence intervals. Results 72 patients received a heart transplant within the 10-year period. Demographics are noted in table 1. Table 2 presents the immunization status as follows: 48.7% for flu vaccine, 55.5% for Hepatitis B, 47.1% for Hepatitis A, 36.1% for MMR, 67.5% for PPSV23, 67.5% for PCV13, 54.1% for Tdap, 83.3% for Varicella and 13.8% for Zoster, and 53.5% for COVID-19. From 2016, an ID consult was required pre-transplant; 45 patients (62.5%) had an ID consult before transplant. ID consult was associated with increased likelihood of receiving the MMR, PCV13, Tdap, and Zoster vaccines (table 3). Table 1Patient demographics Table 2 Immunization status in heart transplant recipients Table 3 Immunization status associated with ID consult Conclusion This study reveals the deficiency of vaccinations in our heart transplant patients, but an ID consult was associated with better immunization rates. To further increase compliance, we propose different interventions including close follow-up with ID, addressing vaccine costs, accessibility limitations, cultural hesitancy, and implementation of protocols. Disclosures All Authors: No reported disclosures.

Mechanism, impact, and effectiveness of herpes zoster vaccines: A comprehensive review

In the past decade, there has been increasing interest in whether a widespread childhood varicella immunization scheme may increase the age-specific incidence of herpes zoster in adults. This proposition is based on evidence that exposure to endemic varicella boosts varicella-zoster virus-specific immunity in adults and that cessation of varicella in the community would result in a decline in the T cell-mediated immunity required to maintain dormancy of varicella-zoster virus in neurons. However, numerous epidemiological studies have failed to fully explore this effect. Quantifying the efficacy of the varicella vaccine is a crucial step in understanding its benefits.

Recognition & management of varicella infections and accuracy of antimicrobial recommendations: Case vignettes study in the US.

In 1995, the CDC recommended one-dose routine varicella immunization for children <12 years of age, expanding its recommendation to two doses in 2006. Today, with widespread varicella vaccination coverage, an estimated 3.5 million cases of varicella, 9,000 hospitalizations, and 100 deaths are prevented annually in the United States. Since varicella infections are now uncommon, health care providers (HCPs) may not recognize varicella infections and may prescribe inappropriate treatment. An online survey of HCPs was conducted to assess recognition and management of varicella infections. Responses to eight varicella vignettes describing patients with varying varicella symptoms were analyzed and descriptive analyses performed. Stratified analysis comparing responses of those licensed before and in/after 1996 was also performed. 153 HCPs (50 nurse practitioners, 103 doctors) completed the survey. Mean age of respondents was 44 years. 62% were female, and 82% were licensed before 1996. Varicella infection was correctly diagnosed 79% of the time. HCPs correctly recognized uncomplicated varicella vignettes 85% of the time versus 61% of the time for complicated varicella vignettes. Antibiotics were recommended 17% of the time and antivirals 18% of the time, of which 25% and 69% (respectively) were not appropriate per guidelines. HCPs licensed before 1996 were better able to recognize varicella compared to those licensed later, but prescribed more antimicrobials medications to treat varicella. Although most HCPs recognized varicella infection, a sizable proportion could not recognize cases with complications, and some of the varicella cases were inappropriately treated with antibiotics and/or antivirals. Additional HCP training and high vaccination coverage are important strategies to avoid inaccurate diagnoses and minimize unnecessary exposure to antimicrobial/antiviral therapies.

Effect of Routine Varicella Immunization on the Epidemiology and Immunogenicity of Varicella and Shingles.

Varicella-zoster virus (VZV) causes varicella as a primary infection and remains latent in the ganglia until it becomes reactivated to cause herpes zoster. Individuals with varicella develop adaptive humoral and cell-mediated immunity. Compromised cell-mediated immunity is thought to contribute to the development of herpes zoster. Recent evidence suggests that changes in the epidemiology of varicella have affected the epidemiology of herpes zoster. The incidence of herpes zoster is higher in older adults; thus, the herpes zoster vaccine is recommended for older adults. However, the incidence of herpes zoster is expected to rise among younger individuals; hence, vaccination with the varicella vaccine should also be considered in younger adults. In order to determine the need for vaccination in different populations, it is important to establish methods to accurately assess the activity of cell-mediated immunity and humoral immunity.

Investigation of economic burden caused by varicella in school aged children in Shenzhen

Objective To understand the economic burden caused by varicella in school aged children in Shenzhen, compare the economic burden under different varicella immunization strategies and provide evidence for the development of targeted varicella prevention and control strategies. Methods A retrospective survey was conducted in 24 primary schools of Shenzhen where varicella outbreaks had been reported. Software SPSS 25.0 was used for analysis, the gender, age and case type specific direct cost, indirect cost and overall cost of varicella cases and the influence of their vaccination status on the economic burden were analyzed by non-parametric test (Kruskal Wallis test for multi-group comparison and Mann Whitney U test for pairwise comparison). Spearman rank correlation test was used to analyze the correlation between ordered variables (age, number of caregivers, number of care days) and the economic burden. Results A total of 515 cases of varicella were surveyed. The difference in economic burden between outpatients and inpatients of varicella was significant. Among the varicella cases surveyed, 426 were not hospitalized, and their average medical cost was 810.00 (400.00–1452.00) yuan, in which 260.00 (200.00–350.00) yuan was direct cost, and 500.00 (200.00–1100.00) yuan was indirect cost, and 23 varicella cases were hospitalized, and their average medical cost was 3020.00 (2050.00–3508.00) yuan, in which 1100.00 (1000.00–1340.00) yuan was direct cost, and 1900.00 (1200.00–2200.00) yuan was indirect cost. Spearman rank correlation test showed a positive correlation between the number of care days, number of caregivers and the medical cost of the varicella cases. There was no gender specific difference in medical cost. The difference in medical cost between the cases with different varicella vaccination status was significant. The medical cost was higher in the cases with 1 dose varicella vaccination than in the cases with 0 dose varicella vaccination. Conclusion The economic burden caused by varicella in school-aged children in Shenzhen was serious. Cases of varicella under different immunization strategy of varicella vaccine had different economic burden.

Catch-up immunization for adolescents and young adults during pre-travel consultation in Japan.

Rubella and measles outbreaks in adults occur because of unimmunized or partially immunized status. Travel clinics play an important role in catch-up measles, rubella, mumps, and varicella immunization for adults. We evaluated the need for catch-up measles, rubella, mumps, and varicella immunization by young adults at our travel clinic. This retrospective observational study was conducted at the National Center for Global Health and Medicine from June 1, 2017 to May 31, 2018. Adults aged 16–49 years who received pre-travel consultation and had childhood immunization records were included. Individuals who fully or partially received planned measles, rubella, mumps, and varicella catch-up immunization were classified as “immunized.” We calculated the proportion of “immunized” individuals and analyzed the factors associated with catch-up measles, rubella, mumps, and varicella immunization at pre-travel consultation using logistic regression analysis. Overall, 3,456 individuals received pre-travel consultations during the study period; 827 (336 men, median age 22 years) had childhood immunization records. The most common trip purposes were study (33%) and tourism (24%). The most common destination was Asia (39%). Catch-up immunization of any measles, rubella, mumps, and varicella vaccine was needed by 755 individuals. After consultation, 20–46% of these participants who needed catchup immunization received at least one dose of immunization. Factors that are negatively associated with measles, rubella, mumps, and varicella catch-up immunization were tourism (odds ratio 0.37 to 0.58), yellow fever vaccination (0.45 to 0.50) (excluding varicella), and each disease history (0.13 to 0.40) (excluding rubella and varicella). Further studies are needed to identify barriers to catch-up immunization.

Concordance of self-reported varicella history and serology among adolescent and adult refugee patients at a primary care clinic in Toronto, Canada

BackgroundPrevious studies have found higher rates of varicella susceptibility among migrants from tropical regions. This study seeks to estimate the prevalence of varicella susceptibility in a cohort of newly arrived refugees and refugee claimants at a primary care clinic in Toronto and to compare patients’ self-reported history of varicella infection with serologic test results. MethodsWe conducted a retrospective chart review of 1888 refugee patients aged 13 years and older rostered at a specialized primary care clinic in Toronto from December 2011 to October 2017. Basic sociodemographic variables, self-reported varicella history, and varicella serologic results were examined. ResultsBased on serologic testing, 8.5% of individuals were varicella non-immune, with highest rates of varicella susceptibility among adolescents aged 13–19 years (13.5%). All adults over age 60 were varicella immune on serology (n = 56). A positive self-reported history of varicella infection was strongly predictive of varicella immunity on serology (PPV 96.8%; 95% CI: 95.2–97.9). A self-reported history of no prior varicella infection did not correlate reliably with serologic test results (NPV 15.8%; 95% CI: 13.3–18.0). A substantial proportion of patients (34.1%) were unsure of their varicella history. ConclusionIdentification and immunization of varicella susceptible refugee newcomers remains a health care priority. Self-reported history of varicella infection had mixed reliability as a predictor of varicella immunity.

Impact of a two-dose varicella immunization program on the incidence of varicella: a multi-year observational study in Shanghai, China

ABSTRACT Background It remains hesitant to include a two-dose varicella vaccine (VarV) in a national routine immunization program in China. We aimed to quantify the impact of the two-dose VarV on varicella incidence in Shanghai. Research design and methods We directly extracted the data of varicella cases and VarV doses in 2013–2020 in Shanghai, and then estimated the effects of two-dose VarV using a Serfling model. Results A two-dose VarV immunization program has been extensively implemented since October 2017 and become free since August 2018 in Shanghai. Before and after this program, varicella cases significantly declined in children (P < 0.01), whereas did not in adults aged >18 years (P = 0.22). Compared to the predicted number of varicella cases, actual number was significantly lower by 8% in 2018 and 28% in 2019. Among children aged 4–6 years, the reduction in varicella cases was largest. Moreover, there was a significant reduction in varicella cases throughout 2020 (P < 0.001), in which the decrease due to social distancing for the COVID-19 was 54%. Conclusions A two-dose VarV immunization program may further reduce approximately one-third of varicella cases in Shanghai. Children <4 years and adults benefit less in this program, which warrants enhancing the immunization.

Long -term persistence of antibodies against varicella in fully immunized healthcare workers: an Italian retrospective cohort study

BackgroundChickenpox is a highly contagious disease caused by the varicella zoster virus (VZV), and in infants, adolescents, adults, pregnant women, and the immunocompromised it can be serious. The best way to prevent chickenpox is immunization with the varicella vaccine. Protective levels of antibodies induced by the varicella vaccine decline over time, but there is currently no formal recommendation for testing anti-varicella zoster virus (VZV) IgG levels in immunized healthcare workers (HCWs).MethodsThe aims of this study were to evaluate the seroprevalence of circulating anti-VZV IgG in a sample a sample of students and residents of the medical school of the University of Bari, the long-term immunogenicity of the varicella vaccine, and the effectiveness of a strategy consisting of a third vaccine booster dose. The study population was screened as part of a biological risk assessment conducted between April 2014 and October 2020. A strategy for the management of non-responders was also examined.ResultsThe 182 students and residents included in the study had a documented history of immunization (two doses of varicella vaccine). The absence of anti-VZV IgG was determined in 34% (62/182; 95%CI = 27.2–41.4%), with serosusceptibility more common among males than females (p < 0.05). After a third varicella dose, seroconversion was achieved in 100% of this previously seronegative group. No serious adverse events were recorded.ConclusionsOne-third of the study population immunized against VZV lacked a protective antibody titer, but a third dose of vaccine restored protection. Since it is highly unlikely that VZV will be eliminated in the immediate future, the loss of immunity in a substantial portion of the population implies a risk of varicella outbreaks in the coming years. Screening for varicella immunity in routine assessments of the biological risk of medical students and HCWs may help to prevent nosocomial VZV infections.

Inadequate Measles, Mumps, Rubella, and Varicella Immunity Among Employees.

Objectives:The purpose of this cohort study was to evaluate measles, mumps, rubella (MMR), and varicella immunity among a population of adult employees receiving primary care in an employer-sponsored health center.Methods:Participants were eligible for MMR and varicella immunity screening if they were an employee receiving primary care in an employer-sponsored health center between January 1, 2019 and November 1, 2020 who could not provide proof of immunization and 1) had it recommended by their provider, 2) specifically requested immunity testing (often because they had heard of measles outbreaks in their country of origin), or 3) were seen for an immigration physical for their Green Card application.Results:Overall, 3494 patients were screened for their MMR immunity. Of these, 3057 were also screened for varicella immunity. Among these patients, 13.9% lacked measles immunity, 0.83% lacked immunity to all 3 components of MMR, and 13.2% lacked varicella immunity. Among the 262 patients who presented specifically for immunity screening, the rates of lacking immunity were higher for all conditions: 22.7% lacked measles immunity and 9.2% lacked varicella immunity.Conclusion:Given declines in immunizations during the COVID-19 pandemic, there is reason to be concerned that measles and varicella-associated morbidity and mortality may rise. Employers, especially those with large foreign-born populations or who require international travel may want to educate their populations about common contagious illnesses and offer immunity validation or vaccinations at no or low cost.

Varicella incidence and vaccination of children in kindergarten and primary school of Longhua District in Shenzhen

Objective To understand the situation of varicella prevalence and vaccination of susceptible population in Longhua District, and to provide reference for the varicella immunization program. Methods A total of 23 706 children from 30 childcare facilities and primary schools in 6 streets were randomly selected throughout the Longhua District. Date on age, grade, recent year and dosage of vaccination, varicella incidence, the overview of vaccination were collected and analyzed. Results The rate of vaccination in childcare facilities and primary schools was 86.01%, including 55.61% of 1 dose and 30.41% of 2 doses of vaccine. The differences of rate vaccination rate between the childcare facilities and primary schools had statistical significance ( χ 2 = 154.95, P < 0.05). Rate of no-vaccination, 1 dose vaccination and 2 doses vaccination across 6 streets differed significantly ( χ 2 = 146.09, 103.93, 127.31, 146.09, P <0.05). There was an increasing positive association between grades and attack rate ( χ 2 = 8.65, P <0.05). The differences of attack rate between the childcare facilities and primary schools was of statistical significance ( χ 2 = 478.69, P <0.05). The differences of attack rate in street of no vaccination, 1 dose vaccination and total attack rate showed statistical significance ( χ 2 = 54.49, 74.59, 151.49, P <0.05). There was an increasing linear trend of attack rate of primary school childrenby each year ( χ 2 = 24.28, P <0.05). The attack rate increased with time after 1 dose vaccination, immune protection was obtuined for a longer period time after additional doses of vaccine. Negative association was found between grades and protective efficacy rate of varicella. The protective rate and efficacy index of different doses of vaccine in different grades were correlated ( r = 0.80, 0.63, P <0.05). It was most effective after 1 dose vaccination among children in junior grade in kindergarten and 2 dose vaccination in senior grade. Conclusion After the implementation of vaccination program in Longhua District, the vaccination rate of 2 doses significantly increased, but not for a long time. Varicella vaccine should be included in immunization programme to protect vulnerable populations. 【摘要】目的 了解水疸疫苗预防接种政策实施后,深圳市龙华区水疸髙发人群的疫苗接种及水疸流行现状,为指导当 地制定水疸免疫规划措施提供参考。 方法 采用随机分层整群抽样方法,选择深圳市龙华区 6 个街道 30 所托幼机构及小 学23 706名儿童进行电子问卷调査,对获得的年龄、年级、最近疫苗接种年份、接种剂次、发病情况、发病时疫苗接种情况 等基础数据进行分析。 结果 龙华区托幼及小学儿童水疸疫苗总接种率为86.01%,其中 1 剂次接种率为55.61%, 2 剂次 为30.41%。托幼机构及小学的接种率差异有统计学意义( χ 2 = 154.95, P <0.05)。各街道未接种率、 1 剂次接种率、 2 剂次接 种率、总接种率差异均有统计学意义( χ 2 值分别为146.09,103.93,127.31,146.09, P 值均<0.05)。年级别罹患率与年级的 髙低呈正比( χ 2 趋势 =8.65, P <0.01),托幼机构与小学的罹患率差异有统计学意义( χ 2 =478.69, P <0.05)。各街道未接种罹患 率、 1 剂次罹患率、总罹患率差异均有统计学意义( χ 2 值分别为54.49, 74.59,151.49, P 值均<0.05)。随间隔年份增加小学 儿童罹患率具有线性趋势( χ 2 趋势 =24.28, P <0.05), 1 剂次水疸疫苗接种后间隔时间越长罹患率越髙, 2 剂次疫苗可保证较长 时间的保护效果。疫苗的保护率与年级的髙低呈反比,各年级不同剂次疫苗保护率及效果指数之间的相关性有统计学意 义（ r 值分别为0.80, 0.63, P 值均<0.05)。接种 1 剂次疫苗及 2 剂次疫苗效果最好的分别为小班、大班。 结论 龙华区政 策实施后 2 剂次疫苗接种率明显提升,但未起到持久效果。建议将水疸疫苗纳人免疫规划,以达到保障易感人群目的。

1387. Current practices in the diagnosis and treatment of varicella infections in the United States

BackgroundThe Advisory Committee on Immunization Practices recommended a 1 dose varicella immunization program in 1996, expanding this to include 2 doses in 2006. As a result, more than 3.5 million cases of varicella, 9,000 hospitalizations, and 100 deaths are prevented annually in the United States. Since varicella infections have become uncommon, the response of health care providers (HCPs) to patients presenting with varicella symptoms may result in misdiagnosis and/ mistreatment. This study investigated the diagnostic and treatment strategies used by HCPs for managing varicella infections in US children.MethodsAn online cross-sectional survey of licensed HCPs was conducted, after an Institution review board approval and HCP consent. 8 clinical vignettes with information on patients with varying varicella symptoms (representing uncomplicated and complicated cases) were presented. For each vignette, HCPs selected a diagnosis and appropriate intervention(s) from pre-determined lists. Descriptive analyses were performed.ResultsA total of 153 HCPs (50 nurses, 103 doctors) completed the survey. Mean age was 44 years, 62% were female, and 82% were licensed after 1995. Varicella infection was correctly diagnosed 79% of the time. HCPs were able to recognize uncomplicated cases of varicella 85% of the time and complicated cases 61% of the time. HCPs recommended the correct intervention 43% of the time for uncomplicated cases and 25% of the time for complicated cases. For example, HCPs recommended antibiotics 17% of the time and/or antivirals 18% of the time (Table 1), of which 25% and 69% (respectively) were not appropriate per the American Academy of Pediatrics guidelines respectively. Antibiotics were incorrectly recommended 6% of the time for uncomplicated cases of varicella.Table 1. Additional Diagnosis & Treatment Results ConclusionGiven the low incidence of varicella infections in the US, complicated cases of varicella may be under-recognized or inappropriately treated by some HCPs. Additional training may help HCPs better recognize/ treat cases of varicella. Further, ensuring high rates of varicella vaccination is important to avoid vaccine preventable conditions and to minimize unnecessary exposure to antimicrobial and antiviral therapies.DisclosuresJaime Fergie, MD, AstraZeneca (Speaker’s Bureau)Sobi, Inc. (Speaker’s Bureau) Manjiri D. Pawaskar, PhD, Merck & Co., Inc (Employee, Shareholder) Phani Veerkani, MD, DrPH, Merck (Research Grant or Support) Salome Samant, MBBS, MPH, Merck & Co., Inc., Kenilworth, NJ, USA (Employee, Shareholder) Carolyn Harley, PhD, Merck (Consultant) Joanna MacEwan, PhD, PRECISIONheor (Employee) Taylor T. Schwartz, MPH, Merck (Consultant, Grant/Research Support, Scientific Research Study Investigator, Research Grant or Support) Shikha Surati, MPH, Merck & Co., Inc. (Employee, Shareholder)

Trend of chickenpox incident cases through absent vaccination in Najaf Governorate-Iraq from January 2009 to May 2014

Background: Chickenpox infection is a common and highly contagious viral disease caused by the varicella zoster virus. It is highly endemic disease with increasing annual incidence in absence of varicella immunization program in Iraq. The predominance of uncomplicated cases in children tends to overshadow the morbidity associated with social and economic burden of families in addition to risk of complication in younger age groups. Chickenpox now has been considered one of the most common vaccine-preventable diseases in many countries including Iraq.Amis of the study: Describing the epidemiology of registered clinical cases of chickenpox in Najaf governorate of January 2009 to May 2014. More over verifying the increasing number of incident cases of chickenpox for future need of varicella vaccine in Iraq.Methodology: A descriptive cross sectional study was conducted of January 2009 to May 2014, and the data was collected of the public health department of the existing anonymous surveillance of chickenpox. Those monthly records were sent of corresponding surveillance units of six districts in Najaf governorate including north of Najaf, south of Najaf, Al-Kufa, Al-manathera, Al-abbassiya and Al-mishkhab districts. The variables included age groups, gender, and district distributions in this study were based on a classification used in the surveillance system in Iraq.Results: The frequency of chickenpox cases in Najaf Governorate revealed an obvious rise of (1076) in 2009 and (2563) in 2010 to (4692) in 2o13. The incidence rate of occurrence of clinical chickenpox cases also shows an obvious rise in 2011 was 408/100000 population. Most often cases occurred in age group 5-14 years (75 %) and only (3.05 %) in those over 45 years. According to gender distribution, there was sustained non-significant preponderance for the male over female. All registered cases had shown the same seasonal distribution with two peaks of infection per year; spring (March, April and May) and early winter (November, December and January) seasons. Median Endemic Index of chickenpox cases in Najaf in May of 2009-2013 was 633 and the number of cases during January through May 2014 was 558.Conclusion: chickenpox is still increasing in incident cases in Najaf governorate which necessitate thinking of varicella vaccine recommendation.