Facilitating working mothers' ability to breastfeed: global trends in guaranteeing breastfeeding breaks at work, 1995-2014.

BACKGROUND: Mothers who work away from home tend to stop breastfeeding earlier than their nonworking counterparts due to workplace barriers. Barriers to breastfeeding discriminate against women and may lead to inequities in children's health outcomes. Guaranteeing paid breastfeeding breaks at work is 1 mechanism that can improve mothers' opportunity to breastfeed in the workplace. OBJECTIVE: This study aimed to assess the trends in the share of countries guaranteeing breastfeeding breaks in the workplace and paid maternal leave that lasts until the infant is 6 months old (the World Health Organization recommended duration for exclusive breastfeeding), between 1995 and 2014. METHODS: Legislation and secondary source data were collected and reviewed for 193 United Nations member states. Legislation was analyzed for content on breastfeeding breaks and maternal leave guarantees. RESULTS: Fifty-one countries (26.7%) in 2014 did not guarantee breastfeeding breaks in any form and 4 countries provided only unpaid breaks or breaks that did not cover the first 6 months of life; since 1995, around 15 countries (10.2%) legislated for such a policy. In 2014, out of 55 countries that did not guarantee paid breastfeeding breaks for the first 6 months after birth, 7 countries guaranteed paid maternal leave for the same duration; 48 countries (25.1%) provided neither paid maternal leave nor paid breastfeeding breaks. CONCLUSION: Progress in the number of countries guaranteeing breastfeeding breaks at work is modest. Adopting measures to facilitate breastfeeding at work can be a critical opportunity for countries to increase breastfeeding rates among the growing number of women in the labor force.

Removing the regional level from the Niger vaccine supply chain.

OBJECTIVE: Since many of the world's vaccine supply chains contain multiple levels, the question remains of whether removing a level could bring efficiencies. METHODS: We utilized HERMES to generate a detailed discrete-event simulation model of Niger's vaccine supply chain and compared the current four-tier (central, regional, district, and integrated health center levels) with a modified three-tier structure (removing the regional level). Different scenarios explored various accompanying shipping policies and frequencies. FINDINGS: Removing the regional level and implementing a collection-based shipping policy from the district stores increases vaccine availability from a mean of 70-100% when districts could collect vaccines at least weekly. Alternatively, implementing a delivery-based shipping policy from the central store monthly in three-route and eight-route scenarios only increases vaccine availability to 87%. Restricting central-to district vaccine shipments to a quarterly schedule for three-route and eight-route scenarios reduces vaccine availability to 49%. The collection-based shipping policy from district stores reduces supply chain logistics cost per dose administered from US$0.14 at baseline to US$0.13 after removing the regional level. CONCLUSION: Removing the regional level from Niger's vaccine supply chain can substantially improve vaccine availability as long as certain concomitant adjustments to shipping policies and frequencies are implemented.

The impact of making vaccines thermostable in Niger's vaccine supply chain.

OBJECTIVE: Determine the effects on the vaccine cold chain of making different types of World Health Organization (WHO) Expanded Program on Immunizations (EPI) vaccines thermostable. METHODS: Utilizing a detailed computational, discrete-event simulation model of the Niger vaccine supply chain, we simulated the impact of making different combinations of the six current EPI vaccines thermostable. FINDINGS: Making any EPI vaccine thermostable relieved existing supply chain bottlenecks (especially at the lowest levels), increased vaccine availability of all EPI vaccines, and decreased cold storage and transport capacity utilization. By far, the most substantial impact came from making the pentavalent vaccine thermostable, increasing its own vaccine availability from 87% to 97% and the vaccine availabilities of all other remaining non-thermostable EPI vaccines to over 93%. By contrast, making each of the other vaccines thermostable had considerably less effect on the remaining vaccines, failing to increase the vaccine availabilities of other vaccines to more than 89%. Making tetanus toxoid vaccine along with the pentavalent thermostable further increased the vaccine availability of all EPI vaccines by at least 1-2%. CONCLUSION: Our study shows the potential benefits of making any of Niger's EPI vaccines thermostable and therefore supports further development of thermostable vaccines. Eliminating the need for refrigerators and freezers should not necessarily be the only benefit and goal of vaccine thermostability. Rather, making even a single vaccine (or some subset of the vaccines) thermostable could free up significant cold storage space for other vaccines, and thereby help alleviate supply chain bottlenecks that occur throughout the world.

How influenza vaccination policy may affect vaccine logistics.

BACKGROUND: When policymakers make decision about the target populations and timing of influenza vaccination, they may not consider the impact on the vaccine supply chains, which may in turn affect vaccine availability. PURPOSE: Our goal is to explore the effects on the Thailand vaccine supply chain of introducing influenza vaccines and varying the target populations and immunization time-frames. METHODS: We Utilized our custom-designed software HERMES (Highly Extensible Resource for Modeling Supply Chains), we developed a detailed, computational discrete-event simulation model of the Thailand's National Immunization Program (NIP) supply chain in Trang Province, Thailand. A suite of experiments simulated introducing influenza vaccines for different target populations and over different time-frames prior to and during the annual influenza season. RESULTS: Introducing influenza vaccines creates bottlenecks that reduce the availability of both influenza vaccines as well as the other NIP vaccines, with provincial to district transport capacity being the primary constraint. Even covering only 25% of the Advisory Committee on Immunization Practice-recommended population while administering the vaccine over six months hinders overall vaccine availability so that only 62% of arriving patients can receive vaccines. Increasing the target population from 25% to 100% progressively worsens these bottlenecks, while increasing influenza vaccination time-frame from 1 to 6 months decreases these bottlenecks. CONCLUSION: Since the choice of target populations for influenza vaccination and the time-frame to deliver this vaccine can substantially affect the flow of all vaccines, policy-makers may want to consider supply chain effects when choosing target populations for a vaccine.

Impact of introducing the pneumococcal and rotavirus vaccines into the routine immunization program in Niger.

OBJECTIVES: We investigated whether introducing the rotavirus and pneumococcal vaccines, which are greatly needed in West Africa, would overwhelm existing supply chains (i.e., the series of steps required to get a vaccine from the manufacturers to the target population) in Niger. METHODS: As part of the Bill and Melinda Gates Foundation-funded Vaccine Modeling Initiative, we developed a computational model to determine the impact of introducing these new vaccines to Niger's Expanded Program on Immunization vaccine supply chain. RESULTS: Introducing either the rotavirus vaccine or the 7-valent pneumococcal conjugate vaccine could overwhelm available storage and transport refrigerator space, creating bottlenecks that would prevent the flow of vaccines down to the clinics. As a result, the availability of all World Health Organization Expanded Program on Immunization vaccines to patients might decrease from an average of 69% to 28.2% (range = 10%-51%). Addition of refrigerator and transport capacity could alleviate this bottleneck. CONCLUSIONS: Our results suggest that the effects on the vaccine supply chain should be considered when introducing a new vaccine and that computational models can help assess evolving needs and prevent problems with vaccine delivery.

Maintaining vaccine delivery following the introduction of the rotavirus and pneumococcal vaccines in Thailand.

Although the substantial burdens of rotavirus and pneumococcal disease have motivated many countries to consider introducing the rotavirus vaccine (RV) and heptavalent pneumococcal conjugate vaccine (PCV-7) to their National Immunization Programs (EPIs), these new vaccines could affect the countries' vaccine supply chains (i.e., the series of steps required to get a vaccine from their manufacturers to patients). We developed detailed computational models of the Trang Province, Thailand, vaccine supply chain to simulate introducing various RV and PCV-7 vaccine presentations and their combinations. Our results showed that the volumes of these new vaccines in addition to current routine vaccines could meet and even exceed (1) the refrigerator space at the provincial district and sub-district levels and (2) the transport cold space at district and sub-district levels preventing other vaccines from being available to patients who arrive to be immunized. Besides the smallest RV presentation (17.1 cm³/dose), all other vaccine introduction scenarios required added storage capacity at the provincial level (range: 20 L-1151 L per month) for the three largest formulations, and district level (range: 1 L-124 L per month) across all introduction scenarios. Similarly, with the exception of the two smallest RV presentation (17.1 cm³/dose), added transport capacity was required at both district and sub-district levels. Added transport capacity required across introduction scenarios from the provincial to district levels ranged from 1 L-187 L, and district to sub-district levels ranged from 1 L-13 L per shipment. Finally, only the smallest RV vaccine presentation (17.1 cm³/dose) had no appreciable effect on vaccine availability at sub-districts. All other RV and PCV-7 vaccines were too large for the current supply chain to handle without modifications such as increasing storage or transport capacity. Introducing these new vaccines to Thailand could have dynamic effects on the availability of all vaccines that may not be initially apparent to decision-makers.

The optimal number of routine vaccines to order at health clinics in low or middle income countries.

In a low or middle income country, determining the correct number of routine vaccines to order at a health clinic can be difficult, especially given the variability in the number of patients arriving, minimal vaccination days and resource (e.g., information technology and refrigerator space) constraints. We developed a spreadsheet model to determine the potential impact of different ordering policies, basing orders on the arrival rates seen in the previous 1, 3, 6, or 12 sessions, or on long-term historical averages (where these might be available) along with various buffer stock levels (range: 5-50%). Experiments varied patient arrival rates (mean range: 1-30 per session), arrival rate distributions (Poisson, Normal, and Uniform) and vaccine vial sizes (range: 1-dose to 10-dose vials). It was found that when the number of doses per vial is small and the expected number of patients is low, the ordering policy has a more significant impact on the ability to meet demand. Using data from more prior sessions to determine arrival rates generally equates to a better ability to meet demand, although the marginal benefit is relatively small after more than 6 sessions are averaged. As expected, the addition of more buffer is helpful in obtaining better performance; however, this advantage also has notable diminishing returns. In general, the long-term demand rate, the vial sizes of the vaccines used and the method of determining the patient arrival rate all have an effect on the ability of a clinic to maximize the demand that is met.

Impact of changing the measles vaccine vial size on Niger's vaccine supply chain: a computational model.

BACKGROUND: Many countries, such as Niger, are considering changing their vaccine vial size presentation and may want to evaluate the subsequent impact on their supply chains, the series of steps required to get vaccines from their manufacturers to patients. The measles vaccine is particularly important in Niger, a country prone to measles outbreaks. METHODS: We developed a detailed discrete event simulation model of the vaccine supply chain representing every vaccine, storage location, refrigerator, freezer, and transport device (e.g., cold trucks, 4 × 4 trucks, and vaccine carriers) in the Niger Expanded Programme on Immunization (EPI). Experiments simulated the impact of replacing the 10-dose measles vial size with 5-dose, 2-dose and 1-dose vial sizes. RESULTS: Switching from the 10-dose to the 5-dose, 2-dose and 1-dose vial sizes decreased the average availability of EPI vaccines for arriving patients from 83% to 82%, 81% and 78%, respectively for a 100% target population size. The switches also changed transport vehicle's utilization from a mean of 58% (range: 4-164%) to means of 59% (range: 4-164%), 62% (range: 4-175%), and 67% (range: 5-192%), respectively, between the regional and district stores, and from a mean of 160% (range: 83-300%) to means of 161% (range: 82-322%), 175% (range: 78-344%), and 198% (range: 88-402%), respectively, between the district to integrated health centres (IHC). The switch also changed district level storage utilization from a mean of 65% to means of 64%, 66% and 68% (range for all scenarios: 3-100%). Finally, accounting for vaccine administration, wastage, and disposal, replacing the 10-dose vial with the 5 or 1-dose vials would increase the cost per immunized patient from $0.47US to $0.71US and $1.26US, respectively. CONCLUSIONS: The switch from the 10-dose measles vaccines to smaller vial sizes could overwhelm the capacities of many storage facilities and transport vehicles as well as increase the cost per vaccinated child.

Replacing the measles ten-dose vaccine presentation with the single-dose presentation in Thailand.

Introduced to minimize open vial wastage, single-dose vaccine vials require more storage space and therefore may affect vaccine supply chains (i.e., the series of steps and processes involved in distributing vaccines from manufacturers to patients). We developed a computational model of Thailand's Trang province vaccine supply chain to analyze the effects of switching from a ten-dose measles vaccine presentation to each of the following: a single-dose measles-mumps-rubella vaccine (which Thailand is currently considering) or a single-dose measles vaccine. While the Trang province vaccine supply chain would generally have enough storage and transport capacity to accommodate the switches, the added volume could push some locations' storage and transport space utilization close to their limits. Single-dose vaccines would allow for more precise ordering and decrease open vial waste, but decrease reserves for unanticipated demand. Moreover, the added disposal and administration costs could far outweigh the costs saved from preventing open vial wastage.

Single versus multi-dose vaccine vials: an economic computational model.

Single-dose vaccine formats can prevent clinic-level vaccine wastage but may incur higher production, medical waste disposal, and storage costs than multi-dose formats. To help guide vaccine developers, manufacturers, distributors, and purchasers, we developed a computational model to predict the potential economic impact of various single-dose versus multi-dose measles (MEA), hemophilus influenzae type B (Hib), Bacille Calmette-Guérin (BCG), yellow fever (YF), and pentavalent (DTP-HepB-Hib) vaccine formats. Lower patient demand favors fewer dose formats. The mean daily patient arrival thresholds for each vaccine format are as follows: for the MEA vaccine, 2 patients/day (below which the single-dose vial and above which the 10-dose vial are least costly); BCG vaccine, 6 patients/day (below, 10-dose vial; above, 20-dose vial); Hib vaccine, 5 patients/day (below, single-dose vial; above, 10-dose vial); YF vaccine, 33 patients/day (below, 5-dose vials; above 50-dose vial); and DTP-HepB-Hib vaccine, 5 patients/day (below, single-dose vial; above, 10-dose vial).

A computer simulation of vaccine prioritization, allocation, and rationing during the 2009 H1N1 influenza pandemic.

In the fall 2009, the University of Pittsburgh Models of Infectious Disease Agent Study (MIDAS) team employed an agent-based computer simulation model (ABM) of the greater Washington, DC, metropolitan region to assist the Office of the Assistant Secretary of Public Preparedness and Response, Department of Health and Human Services, to address several key questions regarding vaccine allocation during the 2009 H1N1 influenza pandemic, including comparing a vaccinating children (i.e., highest transmitters)-first policy versus the Advisory Committee on Immunization Practices (ACIP)-recommended vaccinating at-risk individuals-first policy. Our study supported adherence to the ACIP (instead of a children-first policy) prioritization recommendations for the H1N1 influenza vaccine when vaccine is in limited supply and that within the ACIP groups, children should receive highest priority.

A computer simulation of employee vaccination to mitigate an influenza epidemic.

BACKGROUND: Better understanding the possible effects of vaccinating employees is important and can help policymakers and businesses plan vaccine distribution and administration logistics, especially with the current H1N1 influenza vaccine in short supply. PURPOSE: This article aims to determine the effects of varying vaccine coverage, compliance, administration rates, prioritization, and timing among employees during an influenza pandemic. METHODS: As part of the H1N1 influenza planning efforts of the Models of Infectious Disease Agent Study network, an agent-based computer simulation model was developed for the Washington DC metropolitan region, encompassing five metropolitan statistical areas. Each simulation run involved introducing 100 infectious individuals to initiate a 1.3 reproductive-rate (R(0)) epidemic, consistent with H1N1 parameters to date. Another set of scenarios represented a R(0)=1.6 epidemic. RESULTS: An unmitigated epidemic resulted in substantial productivity losses (a mean of $112.6 million for a serologic 15% attack rate and $193.8 million for a serologic 25% attack rate), even with the relatively low estimated mortality impact of H1N1. Although vaccinating Advisory Committee on Immunization Practices-defined priority groups resulted in the largest savings, vaccinating all remaining workers captured additional savings and, in fact, reduced healthcare workers' and critical infrastructure workers' chances of infection. Moreover, although employee vaccination compliance affected the epidemic, once 20% compliance was achieved, additional increases in compliance provided less incremental benefit. Even though a vast majority of the workplaces in the DC metropolitan region had fewer than 100 employees, focusing on vaccinating only those in larger firms (> or =100 employees) was just as effective in mitigating the epidemic as trying to vaccinate employees in all workplaces. CONCLUSIONS: Timely vaccination of at least 20% of the large-company workforce can play an important role in epidemic mitigation.

Simulating school closure strategies to mitigate an influenza epidemic.

BACKGROUND: There remains substantial debate over the impact of school closure as a mitigation strategy during an influenza pandemic. The ongoing 2009 H1N1 influenza pandemic has provided an unparalleled opportunity to test interventions with the most up-to-date simulations. METHODS: To assist the Allegheny County Health Department during the 2009 H1N1 influenza pandemic, the University of Pittsburgh Models of Infectious Disease Agents Study group employed an agent-based computer simulation model (ABM) of Allegheny County, Pennsylvania, to explore the effects of various school closure strategies on mitigating influenza epidemics of different reproductive rates (R0). RESULTS: Entire school system closures were not more effective than individual school closures. Any type of school closure may need to be maintained throughout most of the epidemic (ie, at least 8 weeks) to have any significant effect on the overall serologic attack rate. In fact, relatively short school closures (ie, 2 weeks or less) may actually slightly increase the overall attack rate by returning susceptible students back into schools in the middle of the epidemic. Varying the illness threshold at which school closures are triggered did not seem to have substantial impact on the effectiveness of school closures, suggesting that short delays in closing schools should not cause concern. CONCLUSIONS: School closures alone may not be able to quell an epidemic but, when maintained for at least 8 weeks, could delay the epidemic peak for up to a week, providing additional time to implement a second more effective intervention such as vaccination.

Economic value of seasonal and pandemic influenza vaccination during pregnancy.

BACKGROUND: The cost-effectiveness of maternal influenza immunization against laboratory-confirmed influenza has never been studied. The current 2009 H1N1 influenza pandemic provides a timely opportunity to perform such analyses. The study objective was to evaluate the cost-effectiveness of maternal influenza vaccination using both single- and 2-dose strategies against laboratory-confirmed influenza secondary to both seasonal epidemics and pandemic influenza outbreaks. METHODS: A cost-effectiveness decision analytic model construct using epidemic and pandemic influenza characteristics from both the societal and third-party payor perspectives. A comparison was made between vaccinating all pregnant women in the United States versus not vaccinating pregnant women. Probabilistic (Monte Carlo) sensitivity analyses were also performed. The main outcome measures were incremental cost-effectiveness ratios (ICERs). RESULTS: Maternal influenza vaccination using either the single- or 2-dose strategy is a cost-effective approach when influenza prevalence > or =7.5% and influenza-attributable mortality is > or =1.05% (consistent with epidemic strains). As the prevalence of influenza and/or the severity of the outbreak increases the incremental value of vaccination also increases. At a higher prevalence of influenza (> or =30%) the single-dose strategy demonstrates cost-savings while the 2-dose strategy remains highly cost-effective (ICER, < or =$6787.77 per quality-adjusted life year). CONCLUSIONS: Maternal influenza immunization is a highly cost-effective intervention at disease rates and severity that correspond to both seasonal influenza epidemics and occasional pandemics. These findings justify ongoing efforts to optimize influenza vaccination during pregnancy from an economic perspective.

Antiviral medications for pregnant women for pandemic and seasonal influenza: an economic computer model.

OBJECTIVE: To estimate the economic value of administering antiviral medications to pregnant women who have come in contact with an infectious individual with influenza. METHODS: A computer-simulation model was developed to predict the potential economic effect of antiviral use for postexposure prophylaxis among pregnant women in both seasonal influenza and pandemic influenza scenarios. The model allowed us to examine the effects of varying influenza exposure risk, antiviral efficacy, antiviral cost, and the probability of different influenza outcomes such as hospitalization, preterm delivery, and mortality. RESULTS: For a variety of pandemic influenza scenarios (attack rate 20% or more, probability of preterm birth for women with influenza 12% or more, mortality for a preterm neonate 2% or more, and probability of influenza-attributable hospitalization 4.8% or more), the postexposure prophylactic use of antiviral medications was strongly cost-effective, with incremental cost-effectiveness ratio values below $50,000 per quality-adjusted life-year. Antiviral prophylaxis became an economically dominant strategy (that is, less costly and more effective) when the influenza attack rate is 20% or more and preterm birth rate is 36% or more, and when attack rate is 30% or more and preterm birth rate is 24% or more. Antiviral prophylaxis was not cost-effective under seasonal influenza conditions. CONCLUSION: These findings support the use of antiviral medications for postexposure prophylaxis among pregnant women in a pandemic influenza scenario but not in a seasonal influenza setting.