The epidemiology of chickenpox in UK 5-year olds: An analysis to inform vaccine policy

Parental acceptance of and preferences for administration of routine varicella vaccination in the UK: A study to inform policy

OBJECTIVES

To explore acceptability of and preferences for the introduction of varicella vaccination to the UK childhood immunisation schedule.

DESIGN

We conducted an online cross-sectional survey exploring parental attitudes towards vaccines in general, and varicella vaccine specifically, and their preferences for how the vaccine should be administered.

PARTICIPANTS

596 parents (76.3% female, 23.3% male, 0.4% other; mean age 33.4 years) whose youngest child was aged 0-5 years.

MAIN OUTCOME MEASURES

Willingness to accept the vaccine for their child and preferences for how the vaccine should be administered (in combination with the MMR vaccine [MMRV], on the same day as the MMR vaccine but as a separate injection [MMR + V], on a separate additional visit).

RESULTS

74.0% of parents (95% CI 70.2% to 77.5%) were extremely/somewhat likely to accept a varicella vaccine for their child if one became available, 18.3% (95% CI 15.3% to 21.8%) were extremely/somewhat unlikely to accept it and 7.7% (95% CI 5.7% to 10.2%) were neither likely nor unlikely. Reasons provided by parents likely to accept the vaccine included protection from complications of chickenpox, trust in the vaccine/healthcare professionals, and wanting their child to avoid their personal experience of chickenpox. Reasons provided by parents who were unlikely included chickenpox not being a serious illness, concern about side effects, and believing it is preferable to catch chickenpox as a child rather than as an adult. A combined MMRV vaccination or additional visit to the surgery were preferred over an additional injection at the same visit.

CONCLUSIONS

Most parents would accept a varicella vaccination. These findings highlight parents' preferences for varicella vaccine administration, information needed to inform vaccine policy and practice and development of a communication strategy.

Severe chickenpox disease and seroprevalence in Sweden - implications for general vaccination

OBJECTIVES

To describe the current panorama of severe chickenpox disease and seroprevalence in Sweden, as a basis for the approaching decision on universal vaccination.

METHODS

We included patients discharged with an International Classification of Diseases, 10th revision-code for chickenpox (B01.1-9) in eight pediatric and infectious diseases departments in Stockholm and Gothenburg in 2012-2014 and reviewed their medical charts. Further, residual serum samples collected from 16 laboratories across Sweden were analyzed for varicella zoster IgG-antibodies to investigate the age-specific seroprevalences.

RESULTS

In all, 218 children and 46 adults were included in the hospital-based study, 87.2% of children and 63.0% of adults had complications. An underlying condition was not associated with an increased risk for complication. In children dehydration (31.7%), bacterial skin infections (29.8%) and neurological involvement (20.6%) were most frequent complications. Among adult cases, 63 % were born abroad. The seroepidemiological analysis included 957 patient samples. Seroprevalence was 66.7% at 5 years and 91.5% at 12 years. Infants and adolescents/adults were overrepresented among admitted patients compared to seroprevalence data.

CONCLUSIONS

Half of all complications in hospitalized chickenpox cases was seen in previously healthy children, which supports universal childhood vaccination. Adult migrants was a risk group for chickenpox hospitalization. Age-specific seroprevalence was similar to neighboring countries.

Managing varicella zoster virus contact and infection in patients on anti-rheumatic therapy

Chickenpox and shingles can be more severe and occasionally life threatening in immunosuppressed patients. As such, some groups warrant a more detailed history, serological testing and consideration of prophylaxis following contact with the virus. Active disease may also require more aggressive treatment with antivirals. Guidance for the use of varicella zoster immunoglobulin has recently been updated by Public Health England with important implications for rheumatology patients.

Cytomegalovirus, Epstein-Barr virus and varicella zoster virus infection in the first two years of life: a cohort study in Bradford, UK

Background

Cytomegalovirus (CMV), Epstein Barr virus (EBV) and varicella-zoster virus (VZV) are common herpesviruses frequently acquired in childhood, which establish persistent, latent infection and are likely to impact the developing immune system. Little is known about the epidemiology of CMV and EBV infections in contemporary UK paediatric populations, particularly whether age at infection differs by ethnic group.

Methods

Children enrolled in the Born in Bradford Allergy and Infection Study had a blood sample taken and a questionnaire completed at 12 and 24 months of age. Ordered logistic regression quantified associations between ethnicity and other risk factors and age at CMV/EBV/VZV infection (<12 months, 12–24 months, uninfected at 24 months).

Results

Pakistani children (n = 472) were more likely to be infected with CMV and EBV at a younger age than White British children (n = 391) (CMV: adjusted odds ratio (OR) 2.53, 95% confidence interval (CI) 1.47–4.33; EBV: adjusted OR 2.16, 95% CI 1.43–3.26). Conversely, Pakistani children had lower odds of being VZV infected in the second year than White British children (adjusted OR 0.57, 95% CI 0.33–0.97). There was a strong association between increasing birth order and later CMV infection in Pakistani children.

Conclusions

We report large differences in CMV and EBV incidence in the first 2 years between Pakistani and White British children born in Bradford, which cannot be explained by differences in risk factors for infection. Our data will inform the optimum schedule for future CMV and EBV vaccination programmes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2319-7) contains supplementary material, which is available to authorized users.

The differences in short- and long-term varicella-zoster virus (VZV) immunoglobulin G levels following varicella vaccination of healthcare workers measured by VZV fluorescent-antibody-to-membrane-antigen assay (FAMA), VZV time-resolved fluorescence immunoassay and a VZV purified glycoprotein enzyme immunoassay

Healthcare workers (HCWs) reporting no history of varicella frequently receive varicella vaccination (vOka) if they test varicella-zoster virus (VZV) immunoglobulin G (IgG) negative. In this study, the utilities of VZV-IgG time-resolved fluorescence immunoassay (VZV-TRFIA) and a commercial VZV-IgG purified glycoprotein enzyme immunoassay (gpEIA) currently used in England for confirming VZV immunity have been compared to the fluorescent-antibody-to-membrane-antigen assay (FAMA). A total of 110 HCWs received two doses of vOka vaccine spaced 6 weeks apart and sera collected pre-vaccination (n = 100), at 6 weeks post-completion of vaccination (n = 86) and at 12-18 months follow-up (n = 73) were analysed. Pre-vaccination, by FAMA, 61·0% sera were VZV IgG negative, and compared to FAMA the sensitivities of VZV-TRFIA and gpEIA were 74·4% [95% confidence interval (CI) 57·9-87·0] and 46·2% (95% CI 30·1-62·8), respectively. Post-completion of vaccination the seroconversion rate by FAMA was 93·7% compared to rates of 95·8% and 70·8% determined by VZV-TRFIA and gpEIA, respectively. At 12-18 months follow-up seropositivity rates by FAMA, VZV-TRFIA and gpEIA were 78·1%, 74·0% and 47·9%, respectively. Compared to FAMA the sensitivities of VZV-TRFIA and gpEIA for measuring VZV IgG following vaccination were 96·4% (95% CI 91·7-98·8) and 74·6% (95% CI 66·5-81·6), respectively. Using both FAMA and VZV-TRFIA to identify healthy adult VZV susceptibles and measure seroconversion showed that vOka vaccination of HCWs is highly immunogenic.

Application of Oral Fluid Assays in Support of Mumps, Rubella and Varicella Control Programs

Detection of specific viral antibody or nucleic acid produced by infection or immunization, using oral fluid samples, offers increased potential for wider population uptake compared to blood sampling. This methodology is well established for the control of HIV and measles infections, but can also be applied to the control of other vaccine preventable infections, and this review describes the application of oral fluid assays in support of mumps, rubella and varicella national immunization programs. In England and Wales individuals with suspected mumps or rubella, based on clinical presentation, can have an oral fluid swab sample taken for case confirmation. Universal varicella immunization of children has led to a drastic reduction of chickenpox in those countries where it is used; however, in England and Wales such a policy has not been instigated. Consequently, in England and Wales most children have had chickenpox by age 10 years; however, small, but significant, numbers of adults remain susceptible. Targeted varicella zoster virus (VZV) immunization of susceptible adolescents offers the potential to reduce the pool of susceptible adults and oral fluid determination of VZV immunity in adolescents is a potential means of identifying susceptible individuals in need of VZV vaccination. The main application of oral fluid testing is in those circumstances where blood sampling is deemed not necessary, or is undesirable, and when the documented sensitivity and specificity of the oral fluid assay methodology to be used is considered sufficient for the purpose intended.

Trends and socioeconomic disparities in preadolescent's health in the UK: evidence from two birth cohorts 32 years apart

BACKGROUND

Compared to children and adults, little is known about changes in adolescent health over time. This study profiles the health of preadolescents in two distinct time periods, 1980 and 2012.

METHODS

Secondary analysis of the British Cohort Study and the Millennium Cohort Study for preadolescents mostly aged between 10 and 11.5 years (range 9.75-13 years). The prevalence/average of, and socioeconomic gradients in, the following were compared between 1980 and 2012; general health problems, anthropometrics, allergic conditions, infectious diseases, health service use, smoking and parental smoking behaviour and maternal adiposity. Socioeconomic status was measured by familial income (3 groups).

RESULTS

There were decreases in the proportion of hospital admissions (Δ=-0.10(-0.09:-0.11)) smoking (Δ=-0.12(-0.11:-0.13)), parental smoking (mother: (Δ=-0.19(-0.18:-0.21)) father: (Δ=-0.35(-0.34:-0.37), infectious diseases (measles: (Δ=-0.46(-0.45:-0.47)) whooping cough: (Δ=-0.07(-0.06:-0.07)) and hearing problems (Δ=-0.04(-0.03:-0.05)). There were no changes in limiting long-standing illness (Δ=0.00 (-0.00:0.00)), or the proportion of children having two or more accidents requiring medical attention (Δ=-0.02(-0.00:-0.02)). There were increases in the proportion overweight (Δ=0.18(0.17:0.19)), maternal overweight(Δ=0.22(0.21:0.23)) and obesity(Δ=0.12(0.11:0.13)), height for age(Δ=0.47(0.44:0.49)), weight for age (Δ=0.68(0.65:0.71)), proportion reporting chicken pox (Δ=0.28(0.27:0.29)), allergic conditions (eczema Δ=0.19(0.18:0.20)), asthma Δ=0.12(0.11:0.13), hay fever Δ=0.15(0.14:0.16)) and wearing glasses (Δ=0.08(0.07:0.09)). There were increases in socioeconomic gradients for limiting long-standing illness, smoking, overweight, weight for age, height for age, wearing glasses, asthma and the onset of puberty.

CONCLUSIONS

There have been reductions in infectious diseases and tobacco exposure among British preadolescents, but overweight and allergic conditions have risen dramatically. Children from deprived families have benefitted least from improvements in health status, and have experienced the largest increases in health risks.

Preventing varicella in children with malignancies: what is the evidence?

PURPOSE OF REVIEW

The prevention of varicella in children with cancer is generally agreed to be an important goal, because of their elevated risk of varicella zoster virus (VZV)-associated morbidity and mortality. However, there is a lack of consensus on the best means of achieving this. Here, we review the existing evidence in relation to postexposure prophylaxis against varicella in this group and summarize data regarding the role of active vaccination.

RECENT FINDINGS

Death from varicella during treatment for cancer is now rare, but VZV disease and its prevention remain significant problems in paediatric oncology practice. Measures to reduce VZV exposure amongst seronegative individuals are often neglected. When exposure is known to have occurred, early administration of varicella zoster immune globulin (VZIG) is generally protective against severe and complicated varicella. However, many centres in the UK and Japan use an oral antiviral agent, aciclovir, in place of VZIG. Published evidence for the efficacy of aciclovir as postexposure prophylaxis (PEP) relates mostly to healthy children, with no controlled studies in the immunocompromised.

SUMMARY

Good evidence already supports the administration of varicella vaccine to healthy susceptible family contacts of children with malignancy, but not to patients themselves. Further data are urgently needed to inform the choice of PEP against VZV in the immunocompromised.