Second-dose varicella vaccination coverage in children and adolescents in a managed care organization in California, 2006-2009

Epidemiology and clinical features of breakthrough varicella in the 9 years after universal vaccination began in Japan

OBJECTIVE

To elucidate the trends and clinical features of virologically diagnosed breakthrough varicella (BV) 9 years after implementation of the universal vaccination program in Japan.

PATIENTS AND METHODS

Study participants were patients with suspected varicella less than 15 years of age who visited 1 of 15 pediatric clinics in the Nagoya VZV Study Group between September 2015 and August 2023. Practitioners collected patient samples and information such as background characteristics, clinical symptoms, and immunization status. All patients had varicella confirmed by real-time polymerase chain reaction assays.

RESULTS

Of 719 patients with suspected varicella, 512 had laboratory-diagnosed varicella and available information on vaccination status. They were divided into 3 groups: 167 with natural varicella, 250 with BV and 1 dose of vaccine, and 95 with BV and 2 doses. The monthly number of patients with varicella decreased gradually during the observation period. Typical seasonal peaks were observed until the 2019-2020 season. The proportion of patients with BV, particularly BV after 2 doses of vaccine, gradually increased. Patients with BV and 2 doses had a significantly lower median age (5 years) than those with 1 dose (6 years) (p < 0.001). The transmission route for BV was unknown in approximately 30-50 % of patients. Duration of fever was significantly longer (p = 0.0138) and the number of skin eruptions was also significantly higher (p = 0.0013) in the 1-dose group than in the 2-dose group.

CONCLUSIONS

Although the number of pediatric patients with varicella declined after implementation of national immunization with 2 doses of varicella vaccine, the proportion of patients with BV, especially those who received 2 doses, gradually increased. Clinical symptoms were significantly milder in patients with BV and 2 doses. Laboratory diagnosis of varicella is becoming increasingly important due to an increase in the proportion of patients with BV who have mild symptoms.

Trend in varicella patients 4 years after implementation of universal two-dose varicella vaccination in Japan

OBJECTIVE

To elucidate the trend and clinical spectrum of virologically diagnosed varicella patients after implementation of universal vaccination as a national immunization program in Japan.

PATIENTS AND METHODS

Study subjects were patients suspected of varicella, less than 15 years of age, who visited 14 pediatric clinics in the Nagoya VZV Study Group from September 2015 to August 2019. Practitioners collected patient samples and information such as backgrounds, clinical symptoms, and previous immunization status. All patients were confirmed as having varicella based on molecular diagnostic assays.

RESULTS

Varicella zoster virus (VZV) DNA was detected in swab samples from 506 (83.1%) of the 609 suspected patients. The 455 varicella patients for whom vaccination status was available were divided into two groups: 180 universal vaccination targets and 275 non-targets. Numbers of monthly varicella patients decreased gradually during the observation period. In the 2016/17 season, the seasonal epidemic of varicella became undetectable in the universal vaccination target group, and starting in the 2017/18 season, it was obscured even in the non-target group. The median age of patients was significantly lower in the universal vaccination target group (3 years) than the non-target group (7 years) (P < 0.001). Vaccination status differed significantly between the two groups (P < 0.001). Most varicella patients were in the non-target group, especially those who had been vaccinated once (60.4%). Frequency of fever (P < 0.001) and number of skin rashes at the time of the first hospital visit (P = 0.001) were significantly higher in the non-target group.

CONCLUSIONS

Although the number of childhood varicella patients declined after implementation of national immunization with two doses of varicella vaccination, sporadic outbreaks still occurred, mainly in the non-universal vaccination target group. Insufficient vaccination of members of this group is likely to be a major reason for small local outbreaks.

Evaluation of two health education interventions to improve the varicella vaccination: a randomized controlled trial from a province in the east China

Background

We evaluated the effect of two Elaboration Likelihood Model (ELM)-based health educational interventions on varicella vaccine (VarV) vaccination among pregnant women in a province in the east China.

Methods

A prospective randomized controlled trial was conducted among 200 pregnant women with ≥12 gestation weeks to test two interventions, including a messaging video and a messaging booklet. The participants were randomly assigned into the control group, the video group or the booklet group. The VarV coverage at 12 and 24 months old was compared among the children of the three groups and relative risks (RRs) were calculated, by using the coverage of the control group as reference. The timeliness of VarV was also assessed. Furthermore, differences in the effects on the knowledge and attitude of VarV vaccination between the two interventions was evaluated.

Results

The VarV coverage of their children by 24 months of age was 86.4%, 76.1% and 56.7% for the video group, the booklet group and the control group, respectively. The relative risks (RRs) for the coverage of VarV at 24 months of age were 4.8 (95% CI: 2.06–11.3) for the video group and 2.4 (95% CI: 1.2–5.1) for the booklet group. The means of delays were 57.3 days in the video group, 76.9 days in the booklet group, and 100.6 days in the control group. The proportion of women who intended to vaccinate their children with VarV was higher in the video group than the booklet group (93.9% vs. 82.1%, p < 0.05).

Conclusions

Our findings indicated that perinatal health education through booklet or video could improve the coverage and schedule adherence for children’s VarV vaccination.

Diagnosis of Urinary Tract Infections in Children

Urinary tract infections (UTIs) are a common occurrence in children. The management and laboratory diagnosis of these infections pose unique challenges that are not encountered in adults. Important factors, such as specimen collection, urinalysis interpretation, culture thresholds, and antimicrobial susceptibility testing, require special consideration in children and will be discussed in detail in the following review.

Effect of ceftriaxone on the outcome of murine pyelonephritis caused by extended-spectrum-β-lactamase-producing Escherichia coli

Urinary tract infections (UTIs) due to extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae in children are becoming more frequent, and they are commonly treated initially with a second- or third-generation cephalosporin. We developed a murine model of ascending UTI caused by ESBL-producing Escherichia coli. Using this model, we investigated the renal bacterial burden, interleukin-6 (IL-6) expression, and histopathological alterations caused by ESBL- and non-ESBL-producing bacteria after 1, 2, or 6 days with or without ceftriaxone therapy. The renal bacterial burden, IL-6 concentration, and histological inflammatory lesions were not significantly different between mice infected with ESBL- and non-ESBL-producing bacteria without treatment at any of the time points examined. Following ceftriaxone administration, the bacterial burden was eliminated in the kidneys of mice infected with ESBL- and non-ESBL-producing bacteria on the 6th postinfection day. The histological analysis demonstrated that among mice treated with ceftriaxone, those infected with ESBL-producing bacteria had more profound renal alterations than those infected with non-ESBL-producing bacteria on the 6th day (P < 0.001). In comparison, microbiological outcomes did not differ significantly between mice infected with ESBL- and non-ESBL-producing bacteria at any of the time points examined. The effectiveness of ceftriaxone in mice with UTIs due to ESBL-producing E. coli may have therapeutic implications; it is, however, hampered by limited activity on the histopathological lesions, a finding that needs further investigation.

Spread of CTX-M-15 extended-spectrum β-lactamase-producing Escherichia coli isolates through household contact and plasmid transfer

We document the household spread of extended-spectrum β-lactamase-producing Escherichia coli. One isolate belonged to sequence type 1193 and caused urinary tract infection in a 4-month-old female, and the other isolate belonged to sequence type 131 and colonized three family members, including the index patient. These isolates carried similar Inc-I1-Iγ plasmids, harboring blaCTX-M-15.

Impact of a routine two-dose varicella vaccination program on varicella epidemiology

OBJECTIVE

One-dose varicella vaccination for children was introduced in the United States in 1995. In 2006, a second dose was recommended to further decrease varicella disease and outbreaks. We describe the impact of the 2-dose vaccination program on varicella incidence, severity, and outbreaks in 2 varicella active surveillance areas.

METHODS

We examined varicella incidence rates and disease characteristics in Antelope Valley (AV), CA, and West Philadelphia, PA, and varicella outbreak characteristics in AV during 1995-2010.

RESULTS

In 2010, varicella incidence was 0.3 cases per 1000 population in AV and 0.1 cases per 1000 population in West Philadelphia: 76% and 67% declines, respectively, since 2006 and 98% declines in both sites since 1995; incidence declined in all age groups during 2006-2010. From 2006-2010, 61.7% of case patients in both surveillance areas had been vaccinated with 1 dose of varicella vaccine and 7.5% with 2 doses. Most vaccinated case patients had <50 lesions with no statistically significant differences among 1- and 2-dose cases (62.8% and 70.3%, respectively). Varicella-related hospitalizations during 2006-2010 declined >40% compared with 2002-2005 and >85% compared with 1995-1998. Twelve varicella outbreaks occurred in AV during 2007-2010, compared with 47 during 2003-2006 and 236 during 1995-1998 (P < .01).

CONCLUSIONS

Varicella incidence, hospitalizations, and outbreaks in 2 active surveillance areas declined substantially during the first 5 years of the 2-dose varicella vaccination program. Declines in incidence across all ages, including infants who are not eligible for varicella vaccination, and adults, in whom vaccination levels are low, provide evidence of the benefit of high levels of immunity in the population.

Factors associated with receipt of two doses of varicella vaccine among adolescents in the United States

BACKGROUND

In 2006, routine two-dose varicella vaccination for all children was recommended, including a second dose catch-up program for older children and adolescents. Recent studies have shown that a second dose of the vaccine provides incremental protection against varicella disease.

METHODS

This study is a cross-sectional analysis of data collected in the National Immunization Survey-Teen 2010 combined with publicly available data related to state immunization requirements. Bivariate and multivariable logistic regression analyses were performed to examine individual-level and state-level factors associated with receipt of two doses of varicella vaccine among 10,542 adolescents 13 to 17 years of age with no history of varicella.

RESULTS

Overall, 58.1% of adolescents without any history of varicella had received two doses of varicella vaccine. Coverage varied widely among states, ranging from 19.7% in South Dakota to 85.3% in Rhode Island. In the multivariable model, receipt of two doses of varicella vaccine was significantly associated with younger age, higher maternal education level, private health insurance, more frequent health care visits, receipt of both quadrivalent meningococcal conjugate and tetanus, diphtheria, and acellular pertussis vaccinations, and residing in a state with two-dose policies for middle school entry. Vaccines for Children program-eligible adolescents were less likely to have received two doses.

CONCLUSION

Two-dose varicella vaccination coverage remained low among adolescents in 2010, despite the universal recommendation. Programs that are aimed specifically at Vaccines for Children program-eligible adolescents, state policies requiring two doses for middle school entry, and broad education and implementation of the adolescent vaccination platform may help to improve varicella vaccination coverage.

Correlates for second-dose varicella vaccination in school-age children in a managed care organization in California

OBJECTIVE

To identify correlates of nonadherence to the recommendation for routine second-dose varicella vaccination in a diverse sample of school-age children.

METHODS

A total of 67,977 children of 4-6 years (51% male, 50% Hispanic) were included in this retrospective cohort study. The second-dose varicella vaccination history was evaluated by using the Kaiser Immunization Tracking System. Correlation and multivariable regression analyses were used to test the association between potential correlates and nonadherence to the second-dose varicella vaccination.

RESULTS

Four-year-old children had a significantly higher vaccination rate (76.1%) than 5-year-olds (43.2%) and 6-year-olds (17.3%) by 12 months after the implementation of routine second-dose varicella vaccination. Non-Hispanic white race [rate ratio (RR): 1.13 (95% CI: 1.11-1.15)], living in an area of >75% adults with a high-school diploma [RR: 1.17 (95% CI: 1.14-1.20)], and having a primary care provider specializing in family medicine [RR: 1.15 (95% CI: 1.11-1.18)] significantly correlated with nonadherence. Missed opportunity was found in 59.7% (n=20,465) of children who did not receive the second-dose varicella vaccine in spite of at least 1 outpatient visit and in 15.8% (n=5407) who received some other vaccines during the follow-up period.

CONCLUSIONS

Efforts targeting non-Hispanic white and black children, parents with a high education level and family medicine physicians might improve uptake of the routine 2-dose varicella vaccination. Incorporation of a requirement for the second-dose varicella vaccine into the school law might help achieve high adherence to the routine 2-dose varicella vaccination in school-age children.