Vaccinations and childhood type 1 diabetes mellitus: a meta-analysis of observational studies

AIMS/HYPOTHESIS

The aim of this study was to investigate the association between routine vaccinations and the risk of childhood type 1 diabetes mellitus by systematically reviewing the published literature and performing meta-analyses where possible.

METHODS

A comprehensive literature search was performed of MEDLINE and EMBASE to identify all studies that compared vaccination rates in children who subsequently developed type 1 diabetes mellitus and in control children. ORs and 95% CIs were obtained from published reports or derived from individual patient data and then combined using a random effects meta-analysis.

RESULTS

In total, 23 studies investigating 16 vaccinations met the inclusion criteria. Eleven of these contributed to meta-analyses which included data from between 359 and 11,828 childhood diabetes cases. Overall, there was no evidence to suggest an association between any of the childhood vaccinations investigated and type 1 diabetes mellitus. The pooled ORs ranged from 0.58 (95% CI 0.24, 1.40) for the measles, mumps and rubella (MMR) vaccination in five studies up to 1.04 (95% CI 0.94, 1.14) for the haemophilus influenza B (HiB) vaccination in 11 studies. Significant heterogeneity was present in most of the pooled analyses, but was markedly reduced when analyses were restricted to study reports with high methodology quality scores. Neither this restriction by quality nor the original authors' adjustments for potential confounding made a substantial difference to the pooled ORs.

CONCLUSIONS/INTERPRETATION

This study provides no evidence of an association between routine vaccinations and childhood type 1 diabetes.

Chickenpox in Poland in 2014

BACKGROUND

A large number of chickenpox cases, occurring especially in children between 0-14 years old and among those who are not vaccinated, indicates the rationale for the use of chickenpox vaccinations. In Poland since 2002, chickenpox vaccination is included in the National Immunisation Programme as recommended. AIM. To assess epidemiological situation of chickenpox in Poland in 2014 in comparison to previous years.

AIM

To assess epidemiological situation of chickenpox in Poland in 2014 in comparison to previous years.

METHODS

The descriptive analysis was based on data retrieved from routine mandatory surveillance system and published in the annual bulletins “Infectious diseases and poisonings in Poland in 2014” and “Vaccinations in Poland in 2014” (1;2). National Immunisation Programme for year 2014 was also used (3).

RESULTS

In 2014, 221 628 cases of chickenpox were registered in Poland. The incidence was 575.9 and was lower than in 2013 (463.6). The highest number of cases was reported in mazowieckie voivodeship (35 321), the lowest in podlaskie voivodeship (5 346). The highest incidence was recorded in children aged 4 years. The chickenpox incidence among men was higher by 12.4% comparing to women (543.4). The incidence among rural residents (595.0) was higher by 9.8 % than among urban residents. Number of cases hospitalized due to mumps was 1 467. Number of people vaccinated against chickenpox was 63 608.

SUMMARY

In 2014, there was increase in the incidence of chickenpox in Poland. Since 2002 the number of people vaccinated against chickenpox increased. The increase in the number of people vaccinated against chickenpox would help maintain the downward trend in subsequent years.

Impact of the US Two-dose Varicella Vaccination Program on the Epidemiology of Varicella Outbreaks: Data from Nine States, 2005-2012

BACKGROUND

A routine 2-dose varicella vaccination program was adopted in 2007 in the US to help further decrease varicella disease and prevent varicella outbreaks. We describe trends and characteristics of varicella outbreaks reported to the Centers for Disease Control and Prevention (CDC) during 2005-2012 from 9 states.

METHODS

Data on varicella outbreaks collected by 9 state health departments were submitted to CDC using the CDC outbreak reporting worksheet. Information was collected on dates of the outbreak, outbreak setting and number of cases by outbreak; aggregate data were provided on the numbers of outbreak-related cases by age group, vaccination status and laboratory confirmation.

RESULTS

Nine hundred and twenty-nine outbreaks were reported from the 6 states, which provided data for each year during 2005-2012. Based on data from these 6 states, the number of outbreaks declined by 78%, decreasing from 147 in 2005 to 33 outbreaks in 2012 (P = 0.0001). There were a total of 1015 varicella outbreaks involving 13,595 cases reported by the 9 states from 2005 to 2012. The size and duration of outbreaks declined significantly over time (P < 0.001). The median size of outbreaks was 12, 9 and 7 cases and median duration of outbreaks was 38, 35 and 26 days during 2005-2006, 2007-2009 and 2010-2012, respectively. Majority of outbreaks (95%) were reported from schools, declining from 97% in 2005-2006 to 89% in 2010-2012. Sixty-five percent of outbreak-related cases occurred among 5-year to 9-year olds, with the proportion declining from 76% in 2005-2006 to 45% during 2010-2012.

CONCLUSIONS

The routine 2-dose varicella vaccination program appears to have significantly reduced the number, size and duration of varicella outbreaks in the US.

Varicella zoster virus infection

Infection with varicella zoster virus (VZV) causes varicella (chickenpox), which can be severe in immunocompromised individuals, infants and adults. Primary infection is followed by latency in ganglionic neurons. During this period, no virus particles are produced and no obvious neuronal damage occurs. Reactivation of the virus leads to virus replication, which causes zoster (shingles) in tissues innervated by the involved neurons, inflammation and cell death - a process that can lead to persistent radicular pain (postherpetic neuralgia). The pathogenesis of postherpetic neuralgia is unknown and it is difficult to treat. Furthermore, other zoster complications can develop, including myelitis, cranial nerve palsies, meningitis, stroke (vasculopathy), retinitis, and gastroenterological infections such as ulcers, pancreatitis and hepatitis. VZV is the only human herpesvirus for which highly effective vaccines are available. After varicella or vaccination, both wild-type and vaccine-type VZV establish latency, and long-term immunity to varicella develops. However, immunity does not protect against reactivation. Thus, two vaccines are used: one to prevent varicella and one to prevent zoster. In this Primer we discuss the pathogenesis, diagnosis, treatment, and prevention of VZV infections, with an emphasis on the molecular events that regulate these diseases. For an illustrated summary of this Primer, visit: http://go.nature.com/14xVI1.

Chickenpox in Poland in 2013

BACKGROUND

A large number of chickenpox cases, occurring especially in children, indicates the rationale for the use of chickenpox vaccinations. In Poland since 2002, chickenpox vaccination is included in the National Immunisation Programme as recommended.

AIM

To assess epidemiological situation of chickenpox in Poland in 2013 in comparison to previous years.

METHODS

The descriptive analysis was based on data retrieved from routine mandatory surveillance system and published in the annual bulletins "Infectious diseases and poisonings in Poland in 2013" and "Vaccinations in Poland in 2013" (Czarkowski MP i in., Warszawa 2014, NIZP-PZH i GIS). National Immunisation Programme for year 2013 was also used.

RESULTS

In 2013, 178 501 cases of chickenpox were registered in Poland. The incidence was 463.6 and was lower than in 2012 (540.5). The highest number of cases was reported in mazowieckie voivodeship, the lowest in podlaskie voivodeship. The highest incidence was recorded in children aged 4 years (6 545.1 per 100,000). The chickenpox incidence among men (491.7) was higher by 12.4% comparing to women (437.3). The incidence among rural residents (497.2) was higher than among urban residents (441.7). Number of cases hospitalized due to mumps was 1 184. Number of people vaccinated against chickenpox was 57 168.

SUMMARY

In 2013, there was decrease in the incidence of chickenpox [corrected] in Poland with small fluctuations. Since 2002 the number of people vaccinated against chickenpox increased. The increase in the number of people vaccinated against chickenpox would help maintain the downward trend in subsequent years.

Improving pediatric immunization rates: description of a resident-led clinical continuous quality improvement project

BACKGROUND AND OBJECTIVES

Increased emphasis is being placed on the continuous quality improvement (CQI) education of residents of all specialties. This article describes a resident-led continuous quality improvement (CQI) project, based on a novel curriculum, to improve the immunization rates of children under 2 years old at the Madsen Family Health Center (MHC).

METHODS

All third-year residents were trained in the FOCUS-PDSA CQI methodology through concurrent didactic lectures and experience leading the CQI team. The CQI team included clinical staff led by a third-year family medicine resident and mentored by a member of the family medicine faculty. Immunization records were distributed to provider-medical assistant teamlets daily for each pediatric patient scheduled in clinic as the intervention. Compliance with the intervention (process measure), as well as immunization rates at 2 and 5 months post-intervention (outcome measure), were monitored.

RESULTS

Immunization records were printed on 84% of clinic days from October 24, 2011 to March 31, 2012. The percentage of patients immunized at baseline was 66%. The percentage immunized as of December 31, 2011 was 96% and was 91% as of March 31, 2012.

CONCLUSIONS

An important educational experience was organized for third-year family medicine residents through learning CQI skills, leading a CQI team, and directing a CQI project to completion. Significant improvement in the percentage of patients under 2 years old immunized at the MHC was achieved by presenting provider-medical assistant teamlets with immunization records of all pediatric patients on the daily clinic schedule.

Study of T helper (17) and T regulatory cells in psoriatic patients receiving live attenuated varicella vaccine therapy in a randomized controlled trial

BACKGROUND

The use of live attenuated varicella vaccine (Varilrix(®)) as an adjuvant treatment in severe cases of psoriasis has recently been postulated. Its efficacy raised questions regarding its possible mechanisms of action.

OBJECTIVE

To compare the efficacy and safety of combining Varilrix(®) and cyclosporine to cyclosporine alone in the treatment of severe psoriasis. Furthermore, to study the expression of T helper (Th)17 and T regulatory (Tregs) cells before and after therapy.

MATERIALS AND METHODS

This randomized controlled trial included 24 psoriatic patients, randomly divided into 2 groups (A and B). All patients received cyclosporine at a daily dose of 2.5 mg/kg/day. In addition, group A received 4 doses of Varilrix(®) once/3 weeks, and group B received 4 doses of subcutaneous saline. Skin biopsies were obtained from all patients before and after therapy and from all controls for estimation of interleukin (IL)-17, IL-22 and Forkhead boxP3 (FoxP3) using RT-PCR.

RESULTS

Group A patients showed a significantly higher % of clinical improvement (P = 0.011), which occurred earlier than group B. At baseline, levels of IL-17 and IL-22 were significantly higher while the level of FoxP3 was significantly lower in patients (P<0.001) compared to controls. After therapy, both groups showed significant reductions in both IL-17 and IL-22 levels, and significant elevation in FoxP3 (P<0.001). This change was significantly more evident in group A patients.

CONCLUSION

Live attenuated varicella vaccine could play a role in the treatment of psoriasis when combined with low dose cyclosporine through accentuating the influence on the Th17/Treg balance.

Varicella-zoster vaccine in the USA: success for control of disease severity, but what next?

In the period from 1990 to 1994, before the introduction of a varicella vaccine to the USA, approximately 100 deaths in otherwise healthy individuals, children and adolescents under 20 years of age, were attributable to varicella complications. The administration of a single-dose vaccine has now been widespread in the USA for nearly 10 years; however, since the effectiveness of a single dose in children under 13 years of age in an outbreak situation is approximately 80%, consideration of a second booster dose is in progress although not yet recommended. Licensure of a measles-mumps-rubella-varicella vaccine may hasten the recommendation.

Successes and remaining challenges after 10 years of varicella vaccination in the USA

Beginning in 1995, universal varicella vaccination was recommended in the USA for all children aged 12-18 months, and all susceptible adolescents and adults. Many physicians were initially sceptical about the need to prevent primary varicella. However, with passage of state daycare and school entry mandates for varicella immunization, national varicella vaccination rates increased to approximately 90% by 2004. Several studies have demonstrated concomitant reductions in varicella-related healthcare utilization, costs and varicella-related mortality among children in the vaccinated age group, as well as adults. Remaining challenges include: first, outbreaks of 'breakthrough' varicella in vaccinated populations, which may prompt a second-dose recommendation, and second, possible increases in the incidence of secondary varicella (zoster) among adults whose natural immunity may wane in the absence of endemic varicella. The latter concern highlights the importance of a promising new varicella vaccine for older adults that may be licensed and recommended in the next 2 years.

Prevention of shingles by varicella zoster virus vaccination

Herpes zoster is caused by reactivation from previous varicella zoster virus (VZV) infection, and affects millions of people worldwide. It primarily affects older adults and those with immune system dysfunction, most likely as a result of reduced or lost VZV-specific cell-mediated immunity. Complications include post-herpetic neuralgia, a potentially debilitating and chronic pain syndrome. Current treatment of herpes zoster and post-herpetic neuralgia involves antiviral agents and analgesics, and is associated with significant economic cost. Results from several clinical trials have determined that a live, attenuated VZV vaccine using the Oka/Merck strain (Zostavax) is safe, elevates VZV-specific cell-mediated immunity, and significantly reduces the incidence of herpes zoster and post-herpetic neuralgia in people over 60 years of age. Regulatory approval has recently been obtained and once launched, it is expected that this vaccine will significantly reduce the morbidity and financial costs associated with herpes zoster. Durability of vaccine response and possible booster vaccination will still need to be determined.

Chickenpox in Poland in 2012

BACKGROUND

A number of chickenpox cases, occurring especially in children, indicates the rationale for the use of chickenpox vaccinations. In Poland since 2002, chickenpox vaccination is included in the National Immunisation Programme as recommended.

AIM

To assess epidemiological situation of chickenpox in Poland in 2012 in comparison to previous years.

METHODS

The descriptive analysis was based on data retrieved from routine mandatory surveillance system and published in the annual bulletins "Infectious diseases and poisonings in Poland in 2012" and "Vaccinations in Poland in 2012" (Czarkowski MP i in., Warszawa 2013, NIZP-PZH i GIS). National Immunisation Programme for year 2012 was also used.

RESULTS

In 2012, 208 276 cases of chickenpox were registered in Poland. The highest number of cases was reported in Śląskie voivodeship, the lowest in Podlaskie voivodeship. Mumps incidence was 540.5 per 100 000 and was higher than in 2011 (448.7). The highest incidence was recorded in children aged 4 years (7 611.5 per 100 000). The chickenpox incidence among men (570.7) was higher than among women (512.2). The incidence among rural residents (553.9) was higher than among urban residents (531.8). Number of cases hospitalized due to mumps was 1 361. Number of people vaccinated against chickenpox was 56 213.

SUMMARY

In 2012, there was an increase in the incidence of smallpox in Poland. This trend is continuing since 2004, which can be partly explained by improved surveillance of the disease.

Different vaccination strategies in Spain and its impact on severe varicella and zoster

Varicella vaccines available in Spain were marketed in 1998 and 2003 for non-routine use. Since 2006 some regions decided to include varicella vaccination in their regional routine vaccination programmes at 15-18 months of age. Other regions chose the strategy of vaccinating susceptible adolescents. This study shows the trends in severe varicella zoster virus infections through the analysis of the hospital discharges related to varicella and herpes zoster in the general population from 2005 to 2010 in Spain. A total of 11,125 hospital discharges related to varicella and 27,736 related to herpes zoster were reported during the study period. The overall annual rate of hospitalization was 4.14 cases per 100,000 for varicella and 10.33 cases per 100,000 for herpes zoster. In children younger than 5 years old varicella hospitalization rate significantly decreased from 46.77 in 2005 to 26.55 per 100,000 in 2010. The hospitalization rate related to herpes zoster slightly increased from 9.71 in 2005 to 10.90 per 100,000 in 2010. This increase was mainly due to the significant increase occurring in the >84 age group, from 69.55 to 97.68 per 100,000. When gathering for regions taking into account varicella vaccine strategy, varicella related hospitalizations decreased significantly more in those regions which included the vaccine at 15-18 months of age as a routine vaccine comparing with those vaccinating at 10-14 years old. No significant differences were found in herpes zoster hospitalization rates regarding the varicella vaccination strategy among regions. Severe varicella infections decreased after implementation of varicella vaccination in Spain. This decrease was significantly higher in regions including the vaccine at 15-18 months of age compared with those vaccinating susceptible adolescents.

Shingles in Alberta: before and after publicly funded varicella vaccination

PURPOSE

A universal publicly funded chickenpox vaccination program was implemented in Alberta in 2002. We examine the epidemiology of medically attended shingles in Alberta from 1994 to 2010.

METHODS

Incident shingles cases (earliest health service utilizations for ICD-9 053 or ICD-10-CA B02) and their co-morbid conditions for the 12 months prior to shingles diagnosis were identified from the records of Alberta's universal, publicly funded health-care insurance system for 1994-2010. Shingles diagnostic codes at least 180 days after the first were classified as recurrent episodes. Denominators for rates were estimated using mid-year population estimates from the Alberta Health Care Insurance Plan Registry. Annual age- and sex-specific rates were estimated. We estimated the proportion of all cases that were hospitalized. We explored the pattern of rates for sex, age-group co-morbidity and year effects and their interactions.

RESULTS

Crude rates of shingles increased over the interval 1994-2010. Most persons had only a single episode of shingles; 4% of cases were hospitalized. Shingles rates were higher among females than males. While only 2% of shingles cases had one or more co-morbidities, this proportion was also higher for females than males. Prior to 2002, all age groups of both sexes experienced increasing annual rates of shingles. However, there was a sharp decline in the rate of shingles for both females and males under the age of 10 years for 2002-2010, the period in which there was publicly funded chickenpox vaccination.

CONCLUSION

The declining rates of shingles among persons under the age of 10 years are consistent with an impact of the chickenpox vaccination program. The trend of increasing rates of shingles among older persons began prior to implementation of vaccination.

Clinical Inquiry: is it safe to vaccinate children against varicella while they're in close contact with a pregnant woman?

Yes. All healthy children without evidence of immunity to varicella who are living in a household with a susceptible pregnant woman should be vaccinated.

Vaccines for prophylaxis of viral infections in patients with hematological malignancies

BACKGROUND

Viral infections cause significant morbidity and mortality in patients with hematological malignancies. It remains uncertain whether viral vaccinations in these patients are supported by good evidence.

OBJECTIVES

We aimed to determine the effectiveness and safety of viral vaccines in patients with hematological malignancies.

SEARCH STRATEGY

We searched Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL (June 2010), reference lists of relevant papers, abstracts from scientific meetings and contacted vaccine manufacturers.

SELECTION CRITERIA

Randomized controlled trials (RCTs) evaluating viral vaccines in patients with hematological malignancies were included.

DATA COLLECTION AND ANALYSIS

Relative risk (RR) was used for binary data and mean difference (MD) for continuous data. Primary outcome was incidence of infection. Secondary outcomes were mortality, incidence of complications and severe viral infection, hospitalization, immune response and adverse effects. Fixed-effect model was used in meta-analyses.

MAIN RESULTS

Eight RCTs were included, with 305 patients in the intervention groups and 288 in the control groups. They evaluated heat-inactivated varicella zoster virus (VZV) vaccine (two trials), influenza vaccines (five trials) and inactivated poliovirus vaccine (IPV) (one trial). Seven trials had high and one trial had moderate risk of bias.VZV vaccine might reduce herpes zoster compared to no vaccine (RR 0.54, 95% CI 0.3 to 1.0, P=0.05), but not statistically significant. Vaccination also demonstrated efficacy in immune response but frequently caused local adverse effects. One trial reported severity score of zoster, which favored vaccination (MD 2.6, 95% CI 0.94 to 4.26, P=0.002).Two RCTs compared inactivated influenza vaccine with no vaccine and reported lower risk of lower respiratory infections (RR 0.39, 95% CI 0.19 to 0.78, P=0.008) and hospitalization (RR 0.17, 95% CI 0.09 to 0.31, P<0.00001) in vaccine recipients. However, vaccine recipients more frequently experienced irritability and local adverse effects. There was no significant difference in seroconversion between one and two doses of influenza vaccine (one trial), or between recombinant and standard influenza vaccine (one trial), or influenza vaccine given with or without re-induction chemotherapy (one trial).The IPV trial comparing vaccination starting at 6 versus 18 months after stem cell transplant (SCT) found no significant difference in seroconversion.

AUTHORS' CONCLUSIONS

Inactivated VZV vaccine might reduce zoster severity in adult SCT recipients. Inactivated influenza vaccine might reduce respiratory infections and hospitalization in adults with multiple myeloma or children with leukemia or lymphoma. However, the quality of evidence is low. Local adverse effects occur frequently. Further high-quality RCTs are needed.

Impact of the routine varicella vaccination programme on varicella epidemiology in Germany

Routine varicella vaccination with one dose for children of 11 to 14 months was recommended in Germany in 2004 to reduce disease incidence and severe complications. A country-wide varicella sentinel surveillance system was initiated in 2005 to detect trends of disease frequency and vaccine uptake and to evaluate the vaccination programme. A convenient sample of about 1,000 paediatricians and general practitioners was recruited to report on a monthly basis on varicella cases by age groups seen in their practice, and on varicella vaccine doses administered. Sentinel data from April 2005 to March 2009 show a reduction of 55% of varicella cases in all ages; 63% in the age group 0-4 years and 38% in 5-9-year-olds. The number of vaccine doses per reporting unit in all regions and physician groups increased during the same period. The number of reported cases as well as administered vaccines differed between physician groups and regions with different reimbursement policies. Where reimbursement was settled early and vaccine doses were increasing varicella cases started to decrease early as well. Besides reimbursement policies the availability and vaccination schedules influenced vaccine uptake. Sentinel surveillance provided valid data on trends for varicella associated morbidity, vaccine uptake and the age distribution of cases. The results confirm that following the introduction of routine varicella vaccination, varicella morbidity started to decline in Germany.

Universal varicella vaccination in the Sicilian paediatric population: rapid uptake of the vaccination programme and morbidity trends over five years

Following the licensure of the Oka/Merck varicella vaccine in Italy in January 2003, the Sicilian health authorities launched a universal vaccination programme in all nine Local Health Units. A two-cohort vaccination strategy was adopted to minimise the shift of the mean age of varicella occurrence to older age groups, with the goal of vaccinating with one dose at least 80% of children in their second year of life and 50% of susceptible adolescents in their 12th year of life. Two studies were implemented in parallel to closely monitor vaccination coverage as well as varicella incidence.

Prevention of congenital rubella and congenital varicella in Europe

Despite the availability of safe and efficacious vaccines, cases of congenital rubella and varicella syndrome still occur in Europe. As of 2004, several countries had high proportions of women of childbearing age that were susceptible to rubella and varicella virus infection.