Determining the optimal vaccine vial size in developing countries: a Monte Carlo simulation approach

Determinants of Measles Vaccine Hesitancy among Sudanese Parents in Khartoum State, Sudan: A Cross-Sectional Study

Determinants of vaccine hesitancy are not yet well understood. This study aims to assess measles vaccine hesitancy and characterize its determinants among Sudanese parents in Omdurman in Khartoum State. A community-based cross-sectional quantitative study was conducted in Khartoum State in February 2019. The Parent Attitudes about Childhood Vaccination (PACV) was used to measure measles vaccine hesitancy. Questions about the sociodemographic characteristics of the family, the perception of the parents about the measles vaccine, and the parental exposure to information were asked. Proportions of vaccine hesitancy and coefficients of linear regression were computed. Five hundred parents were recruited for the study. We found that a significant proportion of participants (about 1 in 5 parents) had hesitations regarding the measles vaccine. Significant predictors of measles vaccine hesitancy were parental exposure to anti-vaccination information or materials (β = −0.478, p-value < 0.001), the parents’ perception of the effectiveness of measles vaccines (β = 0.093, p-value = 0.020), the age of the mother (β = 0.112, p-value = 0.017), the birth rank of the child (β = −0.116, p-value = 0.015), and the total number of the children in the family (β = 0.098, p-value = 0.013). Vaccination access issues were the common justification for parental vaccination hesitancy. Our findings indicate that investment in vaccine communication as well as addressing access issues might be an effective intervention for improving measles vaccine acceptance and, ultimately, measles vaccine coverage.

Cancer chemotherapy drug wastage in a tertiary care hospital in India-A 3-month prospective and 1-year retrospective study

This study prospectively quantified wastage of cancer chemotherapeutic drugs in an oncology unit to find the associated cost in 3 months. Retrospective analysis of drug usage for 12 months was also conducted to determine the expected drug loss in 1 year. The effect of vial sharing was evaluated under the assumption of sharing. A significant drug wastage of 19.72% (95% confidence interval [CI], 14.52-24.93%) in 3 months and 17.14% (95% CI 14.69-19.59%) in 1 year occurred in our oncology unit. Number of vials purchased (r = 0.362, p < 0.01), weight (r = -0.146, P < .01) and body surface area (r = -0.26, P < .01) correlated with the drug wasted. Vial sharing assumption showed a 9% (95% CI, 2.5-15.5%) reduction in cost in 1 year.

Introducing new vaccines in low- and middle-income countries: challenges and approaches

INTRODUCTION

The number of new vaccine introductions (NVIs) in low and middle-income countries (LMICs) has markedly increased since 2010, raising challenges to often overstretched and underfunded health care systems.

AREAS COVERED

We present an overview of some of these challenges, focusing on programmatic decisions, delivery strategy, information and communication, pharmacovigilance and post-licensure evaluation. We also highlight field-based initiatives that may facilitate NVI.

EXPERT COMMENTARY

Some new vaccines targeting populations other than infants require alternative delivery strategies. NVIs impact upon existing supply chain management, in particular vaccines with novel characteristics. A lack of understanding about immunization and misconceptions may be detrimental to NVI, as well as insufficient or poorly trained health care workforce. Many barriers exist to achieving good vaccination coverage. Real-world evaluation of vaccine safety, effectiveness and impact in LMICs may be limited by lack of robust demographic and disease epidemiology data, as well as limited health care and surveillance infrastructure. A thorough planning phase is crucial to define the most suitable delivery strategy based on the vaccine's and country's specificities. A communication plan and social mobilization are essential. Implementation research and innovative approaches applied to logistics, delivery, communication and program evaluation can facilitate NVI.

Cost-effectiveness of providing measles vaccination to all children in Guinea-Bissau

Background: Measles vaccination is associated with major reductions in child mortality and morbidity. In Guinea-Bissau, to limit vaccine wastage, children are only measles-vaccinated if at least six children aged 9–11 months are present at a vaccination session.

Objective: To estimate the incremental cost-effectiveness of providing measles vaccine (MV) to all children regardless of age and number of children present.

Methods: We estimated MV coverage among children living in villages cluster-randomized to MV for all children and among children cluster-randomized to the current restrictive MV policy (status quo). Prices of MV and injection equipment were obtained from the United Nations Children’s Fund (UNICEF). Cost savings of hospital admissions averted were collected from a sample of health facilities. The non-specific mortality effects of MV were estimated and presented as deaths averted and life years gained (LYG) from providing MV-for-all.

Results: MV coverage at 36 months was 97% in MV-for-all clusters and 84% in restrictive MV policy clusters. Conservatively assuming 90% wastage of MV under the MV-for-all policy and 40% under the restrictive MV policy, cost per child vaccinated was USD 3.08 and USD 1.19, respectively. The incremental costs per LYG and death averted of the MV-for-all policy were USD 5.61 and USD 148, respectively. The MV-for-all policy became cost-saving at 88% wastage.

Conclusions: Taking the low cost of MV and the beneficial non-specific effects of MV into consideration, a 10-dose MV vial should be reclassified as a ‘1+ dose vial’. The vial should be opened for a single child, irrespective of age, but can vaccinate up to 10 children.

Deriving effective vaccine allocation strategies for pandemic influenza: Comparison of an agent-based simulation and a compartmental model

Individuals are prioritized based on their risk profiles when allocating limited vaccine stocks during an influenza pandemic. Computationally expensive but realistic agent-based simulations and fast but stylized compartmental models are typically used to derive effective vaccine allocation strategies. A detailed comparison of these two approaches, however, is often omitted. We derive age-specific vaccine allocation strategies to mitigate a pandemic influenza outbreak in Seattle by applying derivative-free optimization to an agent-based simulation and also to a compartmental model. We compare the strategies derived by these two approaches under various infection aggressiveness and vaccine coverage scenarios. We observe that both approaches primarily vaccinate school children, however they may allocate the remaining vaccines in different ways. The vaccine allocation strategies derived by using the agent-based simulation are associated with up to 70% decrease in total cost and 34% reduction in the number of infections compared to the strategies derived by using the compartmental model. Nevertheless, the latter approach may still be competitive for very low and/or very high infection aggressiveness. Our results provide insights about potential differences between the vaccine allocation strategies derived by using agent-based simulations and those derived by using compartmental models.

Non-specific Effects of Vaccines and Stunting: Timing May Be Essential

Background

Bacillus Calmette-Guérin (BCG) vaccination possesses effects on health beyond its target disease, the so called “non-specific effects”. We evaluate these effects, as well as the effect of timing of BCG and other vaccinations, on stunting in Sub-Saharan African (SSA) children under five.

Methods

We use a Big Data design, including cross-sectional data for 368,450 children from 33 SSA countries. Logistic regression analysis is used with control factors at child, mother, household and context level.

Results

Overall, BCG vaccination did not affect stunting in SSA children (OR 1.00 [0.98–1.03]). Timing of BCG vaccination was of importance (β_time = 0.067 [0.061–0.073]): compared to unvaccinated children, BCG was associated with lower odds on stunting for children vaccinated early in life (OR 0.92 [0.89–0.94]) and higher odds for children vaccinated later in infancy (OR 1.64 [1.53–1.76]). Similar findings were done for diphtheria-tetanus-pertussis (DTP)1 and measles vaccination, and when hemoglobin concentration was used as outcome variable.

Conclusions

We found a general time-dependent pattern of non-specific effects of vaccination, with positive associations for vaccinations given early in life and negative associations for vaccinations given later in infancy. If confirmed in further research, our findings may provide a new perspective on the non-specific effects of vaccination.

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BCG was associated with lower odds on stunting when given early in life and with higher odds when given later in infancy.

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Similar associations were found for DTP1 and measles vaccination and with hemoglobin concentration as outcome.

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Time-dependency of non-specific effects provides a new perspective in the field although confirmation is required.

Vaccines possess effects on health beyond their target disease, so called “non-specific effects”. Our results suggest that timing of vaccination may be important for these effects. In African children, BCG vaccination was associated with lower odds on stunting when given in the first month of life and higher odds on stunting when given later in infancy. Comparable time patterns were found for DTP1 and measles vaccination and with hemoglobin concentration as outcome. Findings were made possible by a Big Data design, using data on 368,450 African children that varied considerably in vaccination times and background characteristics. These results, if confirmed in further research, may provide a fundamental new perspective on the non-specific effects of vaccines.

The budget impact of controlling wastage with smaller vials: A data driven model of session sizes in Bangladesh, India (Uttar Pradesh),Mozambique, and Uganda

INTRODUCTION

Open vial vaccine wastage in multi-dose vials is a major contributor to vaccine wastage. Although switching from 10-dose vials to 5-dose vials could reduce wastage, a higher total cost could be triggered because smaller vials cost more to purchase and store.

METHODS

This study drew field data of daily session sizes in local vaccination facilities from Bangladesh, India (Uttar Pradesh), Mozambique, and Uganda, and used Akaike Information Criteria to determine the best fit statistical distribution across various clinic types. These distributions were input to estimate the vaccine wastage using Lee's (2010) model. Inactivated polio vaccine (IPV) immunization was simulated to compare the costs over ten years with 10-dose vials versus 5-dose vials.

RESULTS

By switching from 10- to 5-dose vials, the observed open vial wastage rate due to vial size preference and session size for IPV was reduced from 0.25 to 0.11 in Bangladesh, 0.17 to 0.08 in India (Uttar Pradesh), 0.13 to 0.06 in Mozambique, and 0.09 to 0.04 in Uganda, respectively. The cost savings realized from lower IPV wastage did not offset the higher costs of procurement and storage costs associated with smaller dose presentation.

CONCLUSION

While our model showed that switching from 10-dose vials to 5-dose vials of IPV reduced open vial wastage, it was not cost-saving.

Modular vaccine packaging increases packing efficiency

BACKGROUND

Within a typical vaccine supply chain, vaccines are packaged into individual cylindrical vials (each containing one or more doses) that are bundled together in rectangular "inner packs" for transport via even larger groupings such as cold boxes and vaccine carriers. The variability of vaccine inner pack and vial size may hinder efficient vaccine distribution because it constrains packing of cold boxes and vaccine carriers to quantities that are often inappropriate or suboptimal in the context of country-specific vaccination guidelines.

METHODS

We developed in Microsoft Excel (Microsoft Corp., Redmond, WA) a spreadsheet model that evaluated the impact of different packing schemes for the Benin routine regimen plus the introduction of the Rotarix vaccine. Specifically, we used the model to compare the current packing scheme to that of a proposed modular packing scheme.

RESULTS

Conventional packing of a Dometic RCW25 that aims to maximize fully-immunized children (FICs) results in 123 FICs and a packing efficiency of 81.93% compared to a maximum of 155 FICs and 94.1% efficiency for an alternative modular packaging system.

CONCLUSIONS

Our analysis suggests that modular packaging systems could offer significant advantages over conventional vaccine packaging systems with respect to space efficiency and potential FICs, when they are stored in standard vaccine carrying devices. This allows for more vaccines to be stored within the same volume while also simplifying the procedures used by field workers to pack storage devices. Ultimately, modular packaging systems could be a simple way to help increase vaccine coverage worldwide.

Inactivated polio vaccination using a microneedle patch is immunogenic in the rhesus macaque

The phased replacement of oral polio vaccine (OPV) with inactivated polio vaccine (IPV) is expected to significantly complicate mass vaccination campaigns, which are an important component of the global polio eradication endgame strategy. To simplify mass vaccination with IPV, we developed microneedle patches that are easy to administer, have a small package size, generate no sharps waste and are inexpensive to manufacture. When administered to rhesus macaques, neutralizing antibody titers were equivalent among monkeys vaccinated using microneedle patches and conventional intramuscular injection for IPV types 1 and 2. Serologic response to IPV type 3 vaccination was weaker after microneedle patch vaccination compared to intramuscular injection; however, we suspect the administered type 3 dose was lower due to a flawed pre-production IPV type 3 analytical method. IPV vaccination using microneedle patches was well tolerated by the monkeys. We conclude that IPV vaccination using a microneedle patch is immunogenic in rhesus macaques and may offer a simpler method of IPV vaccination of people to facilitate polio eradication.