Canada's first universal varicella immunization program: Lessons from Prince Edward Island

Characteristics of immunisation support programmes in Canada: a scoping review and environmental scan

OBJECTIVE

To identify, characterise and map the existing knowledge about programmes that provide immunisation support to Canadians and barriers and facilitators to their delivery.

DESIGN

Scoping review and environmental scan.

INTRODUCTION

Vaccine hesitancy may be associated with unmet support needs of individuals. Immunisation support programmes that provide multicomponent approaches can improve vaccine confidence and equitable access.

INCLUSION CRITERIA

Canadian programmes that focus on providing information about immunisation for the general public, but excluding articles targeting health professionals. The primary concept involves mapping the characteristics of programmes and our secondary concept examines barriers and facilitators to programme delivery.

METHODS

The Joanna Briggs Institute (JBI) methodology guided this review, reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. A search strategy was developed and translated for six databases in November 2021 (updated October 2022). Unpublished literature was identified through the Canadian Agency for Drugs and Technologies in Health Grey Matters checklist and other relevant sources. Stakeholders (n=124) from Canadian regional health authorities were also contacted by email for publicly accessible information. Two independent raters screened and extracted data from identified material. Results are presented in tabular form.

RESULTS

The search strategy and environmental scan resulted in 15 287 sources. A total of 161 full-text sources were reviewed after applying eligibility criteria, resulting in 50 articles. Programmes were delivered in multiple Canadian provinces, focusing on various vaccine types. All programmes aimed to increase vaccine uptake and were mostly provided in person. Multidisciplinary delivery teams based on collaborations among multiple entities were credited as a facilitator to programme delivery across settings. Limitations on programme resources, attitudes of programme staff and participants, and systems organisation were identified as barriers to delivery.

CONCLUSIONS

This review highlighted characteristics of immunisation support programmes across various settings and described multiple facilitators and barriers. These findings can inform future interventions that aim to support Canadians in making decisions about immunisation.

Calibration and Evaluation of Quantitative Antibody Titers for Varicella-Zoster Virus by Use of the BioPlex 2200

Most commercially available enzyme immunoassay-based methods have limited sensitivity to detect antibody responses to varicella-zoster virus (VZV) in vaccinated individuals, who produce lower antibody levels than those with natural infection. However, more sensitive methods are either not commercially available or less amenable to high-throughput testing.

Most commercially available enzyme immunoassay-based methods have limited sensitivity to detect antibody responses to varicella-zoster virus (VZV) in vaccinated individuals, who produce lower antibody levels than those with natural infection. However, more sensitive methods are either not commercially available or less amenable to high-throughput testing. The BioPlex 2200 measles, mumps, rubella, and varicella (MMRV) IgG assay (Bio-Rad Laboratories, Hercules, CA) is an automated high-throughput platform based on the microsphere Luminex technology that measures antibodies against measles, mumps, rubella, and varicella viruses simultaneously. Although it has U.S. Food and Drug Administration approval as a qualitative diagnostic test for measles, mumps, rubella, and varicella virus immunity, in this study, we have validated the assay to produce quantitative titers (off label) against the VaccZyme VZV glycoprotein (VZVgp) low-level IgG kit (The Binding Site Ltd., Birmingham, UK) using the World Health Organization international standard. Here, we show that the BioPlex 2200 MMRV IgG assay has sensitivity superior to that of the Zeus enzyme-linked immunosorbent assay (ELISA) VZV IgG assay (Zeus Diagnostics, Branchburg, NJ). Using receiver operating characteristic (ROC) analysis and adjusting the cutoff levels, we improved the sensitivity of the quantitative BioPlex 2200 MMRV IgG assay to 97.4%, while maintaining 100% specificity.

School-based vaccination programmes: a systematic review of the evidence on organisation and delivery in high income countries

Background

Many countries have recently expanded their childhood immunisation programmes. Schools are an increasingly attractive setting for delivery of these new immunisations because of their ability to reach large numbers of children in a short period of time. However, there are organisational challenges to delivery of large-scale vaccination programmes in schools. Understanding the facilitators and barriers is important for improving the delivery of future school-based vaccination programmes.

Methods

We undertook a systematic review of evidence on school-based vaccination programmes in order to understand the influence of organisational factors on the delivery of programmes. Our eligibility criteria were studies that (1) focused on childhood or adolescent vaccination programmes delivered in schools; (2) considered organisational factors that influenced the preparation or delivery of programmes; (3) were conducted in a developed or high-income country; and (4) had been peer reviewed. We searched for articles published in English between 2000 and 2015 using MEDLINE and HMIC electronic databases. Additional studies were identified by searching the Cochrane Library and bibliographies. We extracted data from the studies, assessed quality and the risk of bias, and categorised findings using a thematic framework of eight organisational factors.

Results

We found that most of the recent published literature is from the United States and is concerned with the delivery of pandemic or seasonal flu vaccination programmes at a regional (state) or local level. We found that the literature is largely descriptive and not informed by the use of theory. Despite this, we identified common factors that influence the implementation of programmes. These factors included programme leadership and governance, organisational models and institutional relationships, workforce capacity and roles particularly concerning the school nurse, communication with parents and students, including methods for obtaining consent, and clinic organisation and delivery.

Conclusions

This is the first time that information has been brought together on the organisational factors influencing the delivery of vaccination programmes in school-based settings. An understanding of these factors, underpinned by robust theory-informed research, may help policy-makers and managers design and deliver better programmes. We identified several gaps in the research literature to propose a future research agenda, informed by theories of implementation and organisational change.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4168-0) contains supplementary material, which is available to authorized users.

Increasing Coverage of Appropriate Vaccinations: A Community Guide Systematic Economic Review

CONTEXT

Population-level coverage for immunization against many vaccine-preventable diseases remains below optimal rates in the U.S. The Community Preventive Services Task Force recently recommended several interventions to increase vaccination coverage based on systematic reviews of the evaluation literature. The present study provides the economic results from those reviews.

EVIDENCE ACQUISITION

A systematic review was conducted (search period, January 1980 through February 2012) to identify economic evaluations of 12 interventions recommended by the Task Force. Evidence was drawn from included studies; estimates were constructed for the population reach of each strategy, cost of implementation, and cost per additional vaccinated person because of the intervention. Analyses were conducted in 2014.

EVIDENCE SYNTHESIS

Reminder systems, whether for clients or providers, were among the lowest-cost strategies to implement and the most cost effective in terms of additional people vaccinated. Strategies involving home visits and combination strategies in community settings were both costly and less cost effective. Strategies based in settings such as schools and MCOs that reached the target population achieved additional vaccinations in the middle range of cost effectiveness.

CONCLUSIONS

The interventions recommended by the Task Force differed in reach, cost, and cost effectiveness. This systematic review presents the economic information for 12 effective strategies to increase vaccination coverage that can guide implementers in their choice of interventions to fit their local needs, available resources, and budget.

Digital epidemiology reveals global childhood disease seasonality and the effects of immunization

Public health surveillance systems are important for tracking disease dynamics. In recent years, social and real-time digital data sources have provided new means of studying disease transmission. Such affordable and accessible data have the potential to offer new insights into disease epidemiology at national and international scales. We used the extensive information repository Google Trends to examine the digital epidemiology of a common childhood disease, chicken pox, caused by varicella zoster virus (VZV), over an 11-y period. We (i) report robust seasonal information-seeking behavior for chicken pox using Google data from 36 countries, (ii) validate Google data using clinical chicken pox cases, (iii) demonstrate that Google data can be used to identify recurrent seasonal outbreaks and forecast their magnitude and seasonal timing, and (iv) reveal that VZV immunization significantly dampened seasonal cycles in information-seeking behavior. Our findings provide strong evidence that VZV transmission is seasonal and that seasonal peaks show remarkable latitudinal variation. We attribute the dampened seasonal cycles in chicken pox information-seeking behavior to VZV vaccine-induced reduction of seasonal transmission. These data and the methodological approaches provide a way to track the global burden of childhood disease and illustrate population-level effects of immunization. The global latitudinal patterns in outbreak seasonality could direct future studies of environmental and physiological drivers of disease transmission.

School-Located Vaccination Clinics: Then and Now

School-located vaccination has a long history in the United States. The 2008 Advisory Committee on Immunization Practices (ACIP) recommendation for annual influenza vaccination of all children 6 months through 18 years of age adds approximately 30 million individuals to the overall cohort recommended to have a yearly vaccination. Th\e ability to administer this vast number of vaccinations may be beyond the capacity of primary care providers, leaving schools as an attractive venue for mass immunization clinics.

Thinking about "Think Again" in Canada: assessing a social marketing HIV/AIDS prevention campaign

The Canadian "Think Again" social marketing HIV/AIDS prevention campaign, adapted from an American effort, encourages gay men to rethink their assumptions about their partners' HIV statuses and the risks of unsafe sex with them. To improve future efforts, existing HIV/AIDS prevention initiatives require critical reflection. While a formal evaluation of this campaign has been carried out elsewhere, here we use the campaign as a social marketing case study to illustrate its strengths and weaknesses, as a learning tool for other campaigns. After describing the campaign and its key results, we assess how it utilized central tenets of the social marketing process, such as formative research and the marketing mix. We then speak to the importance of theoretical influence in campaign design and the need to account for social-contextual factors in safer sex decision making. We conclude with a summary of the lessons learned from the assessment of this campaign.

Varicella vaccination for grades 4 and 5 students: from theory to practice

BACKGROUND

In 2002-2003, as part of a pilot project, varicella vaccination was offered to susceptible students in grades 4 and 5 in schools whose health services are provided by a local community services centre in Montréal. This immunization campaign was merged with the hepatitis B immunization programme.

OBJECTIVES

To calculate the proportion of grade 4 and 5 students susceptible to varicella; to calculate the proportion of susceptible students who agree to be vaccinated; to compare the proportion of susceptibles who agree to be vaccinated when varicella vaccination is offered with the first or the second dose of hepatitis B; and to assess whether a catch-up varicella immunization programme would affect the vaccine coverage of a concurrent hepatitis B vaccination programme.

METHODS

The proportions of susceptible students and of parents of susceptibles who consented to vaccination were calculated. The proportions of parents of susceptibles who consented to vaccination were compared for both immunization strategies: varicella vaccination given with the first or second dose of hepatitis B vaccine. Logistic regression was performed to identify possible associations between consent to varicella vaccination and the various variables collected. Rates of vaccine coverage against hepatitis B after two doses were compared for the years 2000-2001 and 2002-2003.

RESULTS

Of 3,856 registered students, 3,486 (90.4%) returned consent forms. Among the 3,272 students for whom information was available, 441 (13.5%) were susceptible, including 394 (89.3%) who consented to vaccination. The rates of vaccine coverage in the schools after two doses of hepatitis B vaccine were exactly the same for the 2000-2001 and 2002-2003 school years.

CONCLUSION

Varicella vaccination of susceptible grade 4 and 5 students associated with a coincident hepatitis B vaccination campaign can be performed without negative impact on the hepatitis B vaccination programme.

Canadian experience with implementation of an acellular pertussis vaccine booster-dose program in adolescents: implications for the United States

BACKGROUND

In Canada, the epidemiology of pertussis has changed during the past decade such that more cases occur in adolescents than in any other age cohort.

METHODS

The implications of the Canadian experience, as well as the experiences of France, Germany, and Australia, on the universal implementation of an acellular pertussis, diphtheria, and tetanus booster vaccine in the United States are discussed.

RESULTS

In 1999, an acellular pertussis vaccine combined with diphtheria and tetanus toxoids formulated for adolescents and adults was licensed for use in Canada. It has taken >5 years for this vaccine to be introduced universally into the immunization programs of all provinces and territories. The delay in implementation has likely been the result of insufficient epidemiologic data available to the National Advisory Committee on Immunization and the lack of a consensus on the appropriate goals of the national pertussis control strategy. Implementation of an immunization program in all parts of the country occurred only after a national consensus was achieved and federal funding was made available for vaccine purchase.

CONCLUSIONS

The Canadian experience demonstrates that an adolescent pertussis vaccine program can be implemented on a national scale after several factors have been considered.

Varicella vaccination for grades 4 and 5 students: from theory to practice

BACKGROUND

In 2002-2003, as part of a pilot project, varicella vaccination was offered to susceptible students in grades 4 and 5 in schools whose health services are provided by a local community services centre in Montréal. This immunization campaign was merged with the hepatitis B immunization programme.

OBJECTIVES

To calculate the proportion of grade 4 and 5 students susceptible to varicella; to calculate the proportion of susceptible students who agree to be vaccinated; to compare the proportion of susceptibles who agree to be vaccinated when varicella vaccination is offered with the first or the second dose of hepatitis B; and to assess whether a catch-up varicella immunization programme would affect the vaccine coverage of a concurrent hepatitis B vaccination programme.

METHODS

The proportions of susceptible students and of parents of susceptibles who consented to vaccination were calculated. The proportions of parents of susceptibles who consented to vaccination were compared for both immunization strategies: varicella vaccination given with the first or second dose of hepatitis B vaccine. Logistic regression was performed to identify possible associations between consent to varicella vaccination and the various variables collected. Rates of vaccine coverage against hepatitis B after two doses were compared for the years 2000-2001 and 2002-2003.

RESULTS

Of 3,856 registered students, 3,486 (90.4%) returned consent forms. Among the 3,272 students for whom information was available, 441 (13.5%) were susceptible, including 394 (89.3%) who consented to vaccination. The rates of vaccine coverage in the schools after two doses of hepatitis B vaccine were exactly the same for the 2000-2001 and 2002-2003 school years.

CONCLUSION

Varicella vaccination of susceptible grade 4 and 5 students associated with a coincident hepatitis B vaccination campaign can be performed without negative impact on the hepatitis B vaccination programme.