Coverage and Determinants of Uptake for Privately Funded Rotavirus Vaccine in a Canadian Birth Cohort, 2008-2013

Improved vaccine coverage for First Nations children receiving first dose on-reserve: a retrospective cohort study in western Canada

INTRODUCTION

Fragmentation in immunisation reporting systems pose challenges in measuring vaccine coverage for First Nations children in Canada. Some Nations have entered into data-sharing agreements with the province of Alberta's health ministry, enabling novel opportunities to calculate coverage.

METHODS

Partnering with a First Nations community in Alberta, this retrospective cohort study calculated routine childhood vaccine coverage. Administrative data for vaccines delivered within and outside the community were linked to calculate partial and complete immunisation coverage in 2013-2019 at ages 2 and 7 years for children living in the community. We also compared vaccine coverage each year for (a) children who were and were not continuous community residents and (b) children who received or not their first vaccine at the on-reserve community health centre. We also calculated the mean complete coverage across all study years with 95% CIs.

RESULTS

For most vaccines, coverage was higher (p<0.05) at ages 2 and 7 years for children that received their first vaccine at the First Nations health centre, compared with those who received their first dose elsewhere. For example, for pneumococcal vaccine, the mean level of complete coverage in 2-year-olds was 55.7% (52.5%-58.8%) for those who received their first vaccine in the community, compared with 33.3% (29.4%-37.3%) for those who did not; it was also higher at 7 years (75.6%, 72.7%-78.5%, compared with 55.5%, 49.7%-61.3%).

CONCLUSION

Initiating the vaccine series at the on-reserve community health centre had a positive impact on coverage. The ability to measure accurate coverage through data-sharing agreements and vaccine record linkage will support First Nations communities in identifying individual and community immunity. The findings also support the transfer of health funding and service delivery to First Nations to improve childhood immunisation uptake.

Factors Associated with the Uptake of Rotavirus and Pneumococcal Conjugate Vaccines among Children in Armenia: Implications for Future New Vaccine Introductions

Advances in vaccinology have resulted in various new vaccines being introduced into recommended immunization schedules. Armenia introduced the rotavirus vaccine (RV) and the pneumococcal conjugate vaccine (PCV) into its national schedule in 2012 and 2014, respectively. Using data from the Armenia Demographic and Health Survey, the uptake of the RV and the PCV among children aged younger than three years was estimated. Multilevel logistic regression models were used to evaluate individual- and community-level factors associated with uptake. Intra-cluster correlations were estimated to explain variations in uptake between clusters. The uptake proportionof each RV dose were 90.0% and 86.6%, while each PCV dose had values of 83.5%, 79.4%, and 75.5%, respectively. Non-uptake was highest among children less than 6 months old, children with one sibling, children from a wealthy family, or children whose living distance to a health clinic was problematic. Significant variability in non-uptake due to cluster differences was found for both RV doses (30.5% and 22.8%, respectively) and for the second PCV dose (53.9%). When developing strategies for new vaccine implementation, characteristics of the child, such as age, siblingship, and distance to a health clinic or residence, should be considered. Further exploration of cluster differences may provide insights based on the increased uptake of these and other new vaccines.

Challenges in ensuring global access to COVID-19 vaccines: production, affordability, allocation, and deployment

The COVID-19 pandemic is unlikely to end until there is global roll-out of vaccines that protect against severe disease and preferably drive herd immunity. Regulators in numerous countries have authorised or approved COVID-19 vaccines for human use, with more expected to be licensed in 2021. Yet having licensed vaccines is not enough to achieve global control of COVID-19: they also need to be produced at scale, priced affordably, allocated globally so that they are available where needed, and widely deployed in local communities. In this Health Policy paper, we review potential challenges to success in each of these dimensions and discuss policy implications. To guide our review, we developed a dashboard to highlight key characteristics of 26 leading vaccine candidates, including efficacy levels, dosing regimens, storage requirements, prices, production capacities in 2021, and stocks reserved for low-income and middle-income countries. We use a traffic-light system to signal the potential contributions of each candidate to achieving global vaccine immunity, highlighting important trade-offs that policy makers need to consider when developing and implementing vaccination programmes. Although specific datapoints are subject to change as the pandemic response progresses, the dashboard will continue to provide a useful lens through which to analyse the key issues affecting the use of COVID-19 vaccines. We also present original data from a 32-country survey (n=26 758) on potential acceptance of COVID-19 vaccines, conducted from October to December, 2020. Vaccine acceptance was highest in Vietnam (98%), India (91%), China (91%), Denmark (87%), and South Korea (87%), and lowest in Serbia (38%), Croatia (41%), France (44%), Lebanon (44%), and Paraguay (51%).

Determinants of self-paid rotavirus vaccination status in Kanazawa, Japan, including socioeconomic factors, parents' perception, and children's characteristics

Background

Japan’s National Immunization Program does not cover rotavirus vaccine and no government subsidies are available. This study aimed to measure the uptake of and determinants that influenced self-paid rotavirus vaccination, including socioeconomic status and relative poverty.

Methods

We conducted a cross-sectional study at health check-ups for all children aged 18 months in Kanazawa, Japan, between December 2017 and July 2018. Community nurses collected information on self-paid vaccination history, parents’ perceptions of and recommendations for rotavirus vaccine, and socioeconomic status in interviews using a unified questionnaire. We used multivariable logistic regression to assess vaccine uptake and possible determinants.

Results

In total, 1282 participants were enrolled. The estimated rotavirus vaccine coverage was 72.9%. Perceptions that rotavirus gastroenteritis was serious and that the rotavirus vaccine was effective, pediatricians’ recommendations, information from the city office, magazine and Internet articles, and higher parental education level were associated with higher rotavirus vaccine uptake. Lower household income was associated with decreased rotavirus vaccine uptake. Vaccine expense, fear of adverse reactions to the vaccine, number of household members and siblings, and children’s characteristics were not correlated with rotavirus vaccination. Poverty was associated with decreased rotavirus vaccine uptake, even after adjustment for other determinants (adjusted odds ratio 0.49, 95% confidence interval: 0.26–0.90).

Conclusion

Parents’ perceptions, socioeconomic status, relative poverty, and pediatricians’ recommendations are determinants of vaccination. This study suggests that appropriate information about rotavirus vaccine, subsidies for those of lower socioeconomic status, and national recommendations are necessary to achieve higher coverage.

Measurement of coverage, compliance and determinants of uptake in a publicly funded rotavirus vaccination programme: a retrospective cohort study

OBJECTIVES

In June 2015, Alberta, Canada instituted a universal publicly funded rotavirus vaccination programme (Rotarix, RV1), with vaccine doses scheduled for 2 and 4 months of age. Vaccination was restricted so that infants were only allowed to receive first dose between 6 and 20 weeks of age, and second dose before eight calendar months of age. We assessed the coverage and schedule non-compliance of rotavirus vaccination for babies born between June 2015 and August 2016, that is, since the inception of the publicly funded rotavirus vaccination programme, and determined factors associated with rotavirus vaccine uptake.

DESIGN

Retrospective cohort study using linked administrative health data.

SETTING

Alberta, Canada.

PARTICIPANTS

Cohort of 66 689 children. PRIMARY AND SECONDARY OUTCOME MEASURES: (1) First and second dose rotavirus vaccination coverage, (2) percent of children non-compliant with recommended vaccine schedule and (3) adjusted ORs for factors associated with vaccination status.

RESULTS

For the 66 689 children included in the study, coverage levels for one-dose and two-dose rotavirus vaccination were 87% and 83%, respectively. In comparison, two-dose diphtheria-tetanus-pertussis-polio-Haemophilus influenzae type b vaccine coverage was 92%, despite having the same dosing schedule. Schedule non-compliance during the publicly funded programme was very low. We observed socioeconomic disparities in the uptake of the vaccine, with income, location of residence and number of children in the household all contributing to the odds of a child being vaccinated with rotavirus.

CONCLUSIONS

Compliance to the recommended rotavirus schedule was very high, suggesting that even with the restrictive rotavirus vaccine schedule, the vaccine can be delivered on-time. However, rotavirus vaccine coverage remained lower than DTaP, a similarly scheduled childhood vaccination. We also observed socioeconomic disparities in vaccine uptake. These findings raise concerns about rotavirus protection in the groups at highest risk for gastrointestinal illness, including low-income and rural populations.

Timeliness and factors associated with rotavirus vaccine uptake among Australian Aboriginal and non-Aboriginal children: A record linkage cohort study

OBJECTIVES

Rotavirus vaccines (RV), included in Australia's National Immunisation Program from mid-July 2007, are unique in strict time limits for administration. Here, we report on timeliness of RV uptake, compare cumulative RV coverage to age 12 months with DTPa, and assess factors associated with receipt of RV among Aboriginal and non-Aboriginal children.

METHODS

Birth records for 681,456 children born in two Australian states in 2007-2012 were probabilistically linked to national immunisation records. We assessed on-time coverage (defined as receipt of vaccine dose between 4 days prior to scheduled date and the recommended upper limit) for RV and compared this to diphtheria-tetanus-pertussis (DTPa) vaccine. Logistic regression modelling was used to assess independent determinants of receipt of RV.

RESULTS

Compared to non-Aboriginal infants, on-time RV coverage was lower for all doses among Aboriginal infants. Post the upper age limit of RV dose2, DTPa dose2 coverage increased by 9-16% to ≥90%, whereas RV coverage remained around 77% (Aboriginal) and 85% (non-Aboriginal). Compared to first-born children, the adjusted odds of receiving ≥1 RV dose if born to a mother with ≥3 previous births was 0.30 (95%CI: 0.27-0.34) among Aboriginal, and 0.53 (95%CI: 0.51-0.55) among non-Aboriginal children. Prematurity (<33 weeks), low birthweight (<1500 g), maternal age <20 years, maternal smoking during pregnancy and living in a disadvantaged area were independently associated with decreased vaccine uptake.

CONCLUSIONS

Aboriginal children are at greater risk of rotavirus disease than non-Aboriginal children and delayed vaccine receipt is substantially higher. Although specific programs targeting groups at risk of delayed vaccination might improve RV coverage, relaxation of upper age restrictions is most readily implementable, and its overall risk-benefit should be evaluated.

Perinatal Risk Factors Associated With Gastroenteritis Hospitalizations in Aboriginal and Non-Aboriginal Children in Western Australia (2000-2012): A Record Linkage Cohort Study

BACKGROUND

Gastroenteritis is a leading cause of childhood morbidity worldwide. We aimed to assess the maternal and infant characteristics and population attributable fractions associated with childhood gastroenteritis-related hospitalizations.

METHODS

We conducted a whole-of-population retrospective birth cohort study of 367,476 children live-born in Western Australia 2000-2012. We identified hospital admissions up to <15 years of age pertaining to these children, with a principal diagnosis code for infectious gastroenteritis. Cox regression was used to obtain the adjusted hazard ratios with 95% confidence intervals and the population attributable fractions associated with each risk factor in Aboriginal and non-Aboriginal children for their first gastroenteritis-related hospital admission.

RESULTS

There were a total of 15,888 gastroenteritis-related hospital admissions (25.7% occurring among non-Aboriginal children). The overall gastroenteritis hospitalization rate for children <15 years of age was 4.6/1000 child-years for non-Aboriginal children and 21.5/1000 child-years for Aboriginal children. Male gender, <20 years of maternal age, preterm birth, low birth weight, residence in remote regions of Western Australia and birth in the pre-rotavirus vaccine era were significant independent risk factors for gastroenteritis hospitalization in both Aboriginal and non-Aboriginal children. Additionally, birth by caesarean section and low socioeconomic status were identified as being associated with gastroenteritis hospitalization in non-Aboriginal children. Population attributable fractions suggest that 39% of all gastroenteritis hospitalizations in non-Aboriginal children (38% in Aboriginal children) could be averted if all children receive the rotavirus vaccine.

CONCLUSIONS

Given the beneficial effect of infant rotavirus vaccination in preventing all-cause gastroenteritis hospitalization, efforts should be taken to optimize rotavirus vaccine coverage in those at highest risk.

Vaccine coverage of children in care of the child welfare system

OBJECTIVE

To assess vaccine coverage for a cohort of children who have been in the care of the child welfare system compared to children in the general population.

METHODS

This retrospective cohort study used population-based administrative health data for a 2008 birth cohort of children from Alberta, Canada. We assessed coverage at ages 2 (n = 44,206) and 7 (n = 42,241) for three vaccines with different administration schedules for children in care (at any period before the age of assessment) and those who had never been in care, comparing them using risk differences and relative risks (RRs). We similarly assessed coverage for children not in care who shared characteristics of children in care.

RESULTS

At age two, vaccination coverage for children in care ranged from 54.3% to 81.4%, depending on vaccine. In comparison, coverage for those not in care ranged from 74.2% to 87.4%. At age seven, coverage for children in care ranged from 53.1% to 65.3%, compared to 76.6% to 83.4% for those not in care. For all vaccines at both ages, the risk for being under-vaccinated was higher for children in care (e.g., diphtheria, pertussis, tetanus, polio, Haemophilus influenzae type b at age 7: RR 2.01, 95% confidence interval [CI] (1.74-2.32). Even for children not in care who had characteristics similar to children in care, we found children in care had lower coverage.

CONCLUSION

Children in care have consistently lower vaccine coverage than children not in care. Policies and practices should promote optimal access to vaccination for these children.

Are we speaking the same language? an argument for the consistent use of terminology and definitions for childhood vaccination indicators

Vaccination indicators are used to measure the health status of individuals or populations and to evaluate the effectiveness of vaccination programs or policies. Ensuring that vaccination indicators are clearly and consistently defined is important for effective communication of outcomes, accurate program evaluation, and comparison between different populations, times, and contexts. The purpose of this commentary is to describe commonly used vaccination indicators and to highlight inconsistencies in how childhood vaccine researchers use and define these terms. The indicators we describe are vaccine coverage, uptake, and rate; vaccination status, initiation, and completion; and up-to-date, timely, partial, and incomplete vaccination. We conclude that many vaccination indicators are not explicitly defined within published research studies and/or are used quite differently across studies. We also note that the choice of indicator in a given study is often driven by program or vaccine specific factors, may be constrained by data availability, and should be chosen to best reflect the outcome of interest. We conclude that the use of consistent language and definitions would promote more effective communication of research findings. We also propose some standardized definitions for common indicators, with the goal of provoking discussion and debate on the issue.

Barriers, supports, and effective interventions for uptake of human papillomavirus- and other vaccines within global and Canadian Indigenous peoples: a systematic review protocol

BACKGROUND

Despite the existence of human papilloma virus (HPV) vaccines with demonstrated safety and effectiveness and funded HPV vaccination programs, coverage rates are persistently lower and cervical cancer burden higher among Canadian Indigenous peoples. Barriers and supports to HPV vaccination in Indigenous peoples have not been systematically documented, nor have interventions to increase uptake in this population. This protocol aims to appraise the literature in Canadian and global Indigenous peoples, relating to documented barriers and supports to vaccination and interventions to increase acceptability/uptake or reduce hesitancy of vaccination. Although HPV vaccination is the primary focus, we anticipate only a small number of relevant studies to emerge from the search and will, therefore, employ a broad search strategy to capture literature related to both HPV vaccination and vaccination in general in global Indigenous peoples.

METHODS

Eligible studies will include global Indigenous peoples and discuss barriers or supports and/or interventions to improve uptake or to reduce hesitancy, for the HPV vaccine and/or other vaccines. Primary outcomes are documented barriers or supports or interventions. All study designs meeting inclusion criteria will be considered, without restricting by language, location, or data type. We will use an a priori search strategy, comprised of key words and controlled vocabulary terms, developed in consultation with an academic librarian, and reviewed by a second academic librarian using the PRESS checklist. We will search several electronic databases from date of inception, without restrictions. A pre-defined group of global Indigenous websites will be reviewed for relevant gray literature. Bibliographic searches will be conducted for all included studies to identify relevant reviews. Data analysis will include an inductive, qualitative, thematic synthesis and a quantitative analysis of measured barriers and supports, as well as a descriptive synthesis and quantitative summary of measures for interventions.

DISCUSSION

To our knowledge, this study will contribute the first systematic review of documented barriers, supports, and interventions for vaccination in general and for HPV vaccination. The results of this study are expected to inform future research, policies, programs, and community-driven initiatives to enhance acceptability and uptake of HPV vaccination among Indigenous peoples.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO Registration Number: CRD42017048844.