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1.
Lancet Public Health ; 7(4): e356-e365, 2022 04.
Article in English | MEDLINE | ID: mdl-35276093

ABSTRACT

BACKGROUND: Face mask wearing has been an important part of the response to the COVID-19 pandemic. As vaccination coverage progresses in countries, relaxation of such practices is increasing. Subsequent COVID-19 surges have raised the questions of whether face masks should be encouraged or required and for how long. Here, we aim to assess the value of maintaining face masks use indoors according to different COVID-19 vaccination coverage levels in the USA. METHODS: In this computational simulation-model study, we developed and used a Monte Carlo simulation model representing the US population and SARS-CoV-2 spread. Simulation experiments compared what would happen if face masks were used versus not used until given final vaccination coverages were achieved. Different scenarios varied the target vaccination coverage (70-90%), the date these coverages were achieved (Jan 1, 2022, to July 1, 2022), and the date the population discontinued wearing face masks. FINDINGS: Simulation experiments revealed that maintaining face mask use (at the coverage seen in the USA from March, 2020, to July, 2020) until target vaccination coverages were achieved was cost-effective and in many cases cost saving from both the societal and third-party payer perspectives across nearly all scenarios explored. Face mask use was estimated to be cost-effective and usually cost saving when the cost of face masks per person per day was ≤US$1·25. In all scenarios, it was estimated to be cost-effective to maintain face mask use for about 2-10 weeks beyond the date that target vaccination coverage (70-90%) was achieved, with this added duration being longer when the target coverage was achieved during winter versus summer. Factors that might increase the transmissibility of the virus (eg, emergence of the delta [B.1.617.2] and omicron [B.1.1.529] variants), or decrease vaccine effectiveness (eg, waning immunity or escape variants), or increase social interactions among certain segments of the population, only increased the cost savings or cost-effectiveness provided by maintaining face mask use. INTERPRETATION: Our study provides strong support for maintaining face mask use until and a short time after achieving various final vaccination coverage levels, given that maintaining face mask use can be not just cost-effective, but even cost saving. The emergence of the omicron variant and the prospect of future variants that might be more transmissible and reduce vaccine effectiveness only increases the value of face masks. FUNDING: The Agency for Healthcare Research and Quality, the National Institute of General Medical Sciences, the National Science Foundation, the National Center for Advancing Translational Sciences, and the City University of New York.


Subject(s)
COVID-19 , Vaccination Coverage , COVID-19/prevention & control , COVID-19 Vaccines , Humans , Masks , Pandemics/prevention & control , SARS-CoV-2
2.
Pediatr Res ; 91(1): 254-260, 2022 01.
Article in English | MEDLINE | ID: mdl-33664477

ABSTRACT

BACKGROUND: Teaching caregivers to respond to normal infant night awakenings in ways other than feeding is a common obesity prevention effort. Models can simulate caregiver feeding behavior while controlling for variables that are difficult to manipulate or measure in real life. METHODS: We developed a virtual infant model representing an infant with an embedded metabolism and his/her daily sleep, awakenings, and feeds from their caregiver each day as the infant aged from 6 to 12 months (recommended age to introduce solids). We then simulated different night feeding interventions and their impact on infant body mass index (BMI). RESULTS: Reducing the likelihood of feeding during normal night wakings from 79% to 50% to 10% lowered infant BMI from the 84th to the 75th to the 62nd percentile by 12 months, respectively, among caregivers who did not adaptively feed (e.g., adjust portion sizes of solid foods with infant growth). Among caregivers who adaptively feed, all scenarios resulted in relatively stable BMI percentiles, and progressively reducing feeding probability by 10% each month showed the least fluctuations. CONCLUSIONS: Reducing night feeding has the potential to impact infant BMI, (e.g., 10% lower probability can reduce BMI by 20 percentile points) especially among caregivers who do not adaptively feed. IMPACT: Teaching caregivers to respond to infant night waking with other soothing behaviors besides feeding has the potential to reduce infant BMI. When reducing the likelihood of feeding during night wakings from 79% to 50% to 10%, infants dropped from the 84th BMI percentile to the 75th to the 62nd by 12 months, respectively, among caregivers who do not adaptively feed. Night-feeding interventions have a greater impact when caregivers do not adaptively feed their infant based on their growth compared to caregivers who do adaptively feed. Night-feeding interventions should be one of the several tools in a multi-component intervention for childhood obesity prevention.


Subject(s)
Body Mass Index , Circadian Rhythm , Feeding Behavior , Caregivers , Humans , Infant , Models, Theoretical
3.
Vaccine ; 39(31): 4335-4342, 2021 07 13.
Article in English | MEDLINE | ID: mdl-34158215

ABSTRACT

INTRODUCTION: Single-dose rotavirus vaccines, which are used by a majority of countries, are some of the largest-sized vaccines in immunization programs, and have been shown to constrain supply chains and cause bottlenecks. Efforts have been made to reduce the size of the single-dose vaccines; however, with two-dose, five-dose and ten-dose options available, the question then is whether using multi-dose instead of single-dose rotavirus vaccines will improve vaccine availability. METHODS: We used HERMES-generated simulation models of the vaccine supply chains of the Republic of Benin, Mozambique, and Bihar, a state in India, to evaluate the operational and economic impact of implementing each of the nine different rotavirus vaccine presentations. RESULTS: Among single-dose rotavirus vaccines, using Rotarix RV1 MMP (multi-monodose presentation) led to the highest rotavirus vaccine availability (49-80%) and total vaccine availability (56-79%), and decreased total costs per dose administered ($0.02-$0.10) compared to using any other single-dose rotavirus vaccine. Using two-dose ROTASIIL decreased rotavirus vaccine availability by 3-6% across each supply chain compared to Rotarix RV1 MMP, the smallest single-dose vaccine. Using a five-dose rotavirus vaccine improved rotavirus vaccine availability (52-92%) and total vaccine availability (60-85%) compared to single-dose and two-dose vaccines. Further, using the ten-dose vaccine led to the highest rotavirus vaccine availability compared to all other rotavirus vaccines in both Benin and Bihar. CONCLUSION: Our results show that countries that implement five-dose or ten-dose rotavirus vaccines consistently reduce cold chain constraints and achieve higher rotavirus and total vaccine availability compared to using either single-dose or two-dose rotavirus vaccines.


Subject(s)
Rotavirus Infections , Rotavirus Vaccines , Rotavirus , Benin , Humans , Immunization Programs , India , Infant , Mozambique , Rotavirus Infections/prevention & control , Vaccines, Attenuated
4.
J Infect Dis ; 224(6): 938-948, 2021 09 17.
Article in English | MEDLINE | ID: mdl-33954775

ABSTRACT

BACKGROUND: With multiple coronavirus disease 2019 (COVID-19) vaccines available, understanding the epidemiologic, clinical, and economic value of increasing coverage levels and expediting vaccination is important. METHODS: We developed a computational model (transmission and age-stratified clinical and economics outcome model) representing the United States population, COVID-19 coronavirus spread (February 2020-December 2022), and vaccination to determine the impact of increasing coverage and expediting time to achieve coverage. RESULTS: When achieving a given vaccination coverage in 270 days (70% vaccine efficacy), every 1% increase in coverage can avert an average of 876 800 (217 000-2 398 000) cases, varying with the number of people already vaccinated. For example, each 1% increase between 40% and 50% coverage can prevent 1.5 million cases, 56 240 hospitalizations, and 6660 deaths; gain 77 590 quality-adjusted life-years (QALYs); and save $602.8 million in direct medical costs and $1.3 billion in productivity losses. Expediting to 180 days could save an additional 5.8 million cases, 215 790 hospitalizations, 26 370 deaths, 206 520 QALYs, $3.5 billion in direct medical costs, and $4.3 billion in productivity losses. CONCLUSIONS: Our study quantifies the potential value of decreasing vaccine hesitancy and increasing vaccination coverage and how this value may decrease with the time it takes to achieve coverage, emphasizing the need to reach high coverage levels as soon as possible, especially before the fall/winter.


Subject(s)
COVID-19 Vaccines/economics , Cost-Benefit Analysis , Vaccination/economics , COVID-19/prevention & control , COVID-19 Vaccines/administration & dosage , Humans , Models, Economic , SARS-CoV-2 , United States , Vaccination/statistics & numerical data
5.
Am J Prev Med ; 60(5): 605-613, 2021 05.
Article in English | MEDLINE | ID: mdl-33632650

ABSTRACT

INTRODUCTION: During a pandemic, there are many situations in which the first available vaccines may not have as high effectiveness as vaccines that are still under development or vaccines that are not yet ready for distribution, raising the question of whether it is better to go with what is available now or wait. METHODS: In 2020, the team developed a computational model that represents the U.S. population, COVID-19 coronavirus spread, and vaccines with different possible efficacies (to prevent infection or to reduce severe disease) and vaccination timings to estimate the clinical and economic value of vaccination. RESULTS: Except for a limited number of situations, mainly early on in a pandemic and for a vaccine that prevents infection, when an initial vaccine is available, waiting for a vaccine with a higher efficacy results in additional hospitalizations and costs over the course of the pandemic. For example, if a vaccine with a 50% efficacy in preventing infection becomes available when 10% of the population has already been infected, waiting until 40% of the population are infected for a vaccine with 80% efficacy in preventing infection results in 15.6 million additional cases and 1.5 million additional hospitalizations, costing $20.6 billion more in direct medical costs and $12.4 billion more in productivity losses. CONCLUSIONS: This study shows that there are relatively few situations in which it is worth foregoing the first COVID-19 vaccine available in favor of a vaccine that becomes available later on in the pandemic even if the latter vaccine has a substantially higher efficacy.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , COVID-19/epidemiology , Computer Simulation , Humans , Pandemics , United States/epidemiology , Vaccination
6.
Infect Control Hosp Epidemiol ; 42(11): 1318-1326, 2021 11.
Article in English | MEDLINE | ID: mdl-33427134

ABSTRACT

OBJECTIVE: Due to shortages of N95 respirators during the coronavirus disease 2019 (COVID-19) pandemic, it is necessary to estimate the number of N95s required for healthcare workers (HCWs) to inform manufacturing targets and resource allocation. METHODS: We developed a model to determine the number of N95 respirators needed for HCWs both in a single acute-care hospital and the United States. RESULTS: For an acute-care hospital with 400 all-cause monthly admissions, the number of N95 respirators needed to manage COVID-19 patients admitted during a month ranges from 113 (95% interpercentile range [IPR], 50-229) if 0.5% of admissions are COVID-19 patients to 22,101 (95% IPR, 5,904-25,881) if 100% of admissions are COVID-19 patients (assuming single use per respirator, and 10 encounters between HCWs and each COVID-19 patient per day). The number of N95s needed decreases to a range of 22 (95% IPR, 10-43) to 4,445 (95% IPR, 1,975-8,684) if each N95 is used for 5 patient encounters. Varying monthly all-cause admissions to 2,000 requires 6,645-13,404 respirators with a 60% COVID-19 admission prevalence, 10 HCW-patient encounters, and reusing N95s 5-10 times. Nationally, the number of N95 respirators needed over the course of the pandemic ranges from 86 million (95% IPR, 37.1-200.6 million) to 1.6 billion (95% IPR, 0.7-3.6 billion) as 5%-90% of the population is exposed (single-use). This number ranges from 17.4 million (95% IPR, 7.3-41 million) to 312.3 million (95% IPR, 131.5-737.3 million) using each respirator for 5 encounters. CONCLUSIONS: We quantified the number of N95 respirators needed for a given acute-care hospital and nationally during the COVID-19 pandemic under varying conditions.


Subject(s)
COVID-19 , Pandemics , Health Personnel , Hospitals , Humans , Masks , N95 Respirators , Pandemics/prevention & control , SARS-CoV-2 , United States/epidemiology
7.
Am J Prev Med ; 60(3): 360-368, 2021 03.
Article in English | MEDLINE | ID: mdl-33516583

ABSTRACT

INTRODUCTION: With norovirus vaccine candidates currently under development, now is the time to identify the vaccine characteristics and implementation thresholds at which vaccination becomes cost effective and cost saving in a community setting. METHODS: In 2020, a norovirus transmission, clinical, and economics computational simulation model representing different U.S. population segments was developed to simulate the spread of norovirus and the potential impact of vaccinating children aged <5 years and older adults (aged ≥65 years). RESULTS: Compared with no vaccination, vaccinating preschool-aged children averted 8%-72% of symptomatic norovirus cases in a community, whereas vaccinating older adults averted 2%-29% of symptomatic cases (varying with vaccine efficacy [25%-75%] and vaccination coverage [10%-80%]). Vaccination with a 25% vaccine efficacy was cost effective (incremental cost-effectiveness ratio ≤$50,000 per quality-adjusted life year) when vaccination cost ≤$445 and cost saving at ≤$370 when vaccinating preschool-aged children and ≤$42 and ≤$30, respectively, when vaccinating older adults. With a 50% vaccine efficacy, vaccination was cost effective when it cost ≤$1,190 and cost saving at ≤$930 when vaccinating preschool-aged children and ≤$110 and ≤$64, respectively, when vaccinating older adults. These cost thresholds (cost effective and cost saving, respectively) further increased with a 75% vaccine efficacy to ≤$1,600 and ≤$1,300 for preschool-aged children and ≤$165 and ≤$100 for older adults. CONCLUSIONS: This study outlines thresholds at which a norovirus vaccine would be cost effective and cost saving in the community when vaccinating children aged <5 years and older adults. Establishing these thresholds can help provide decision makers with targets to consider when developing and implementing a norovirus vaccine.


Subject(s)
Norovirus , Vaccines , Aged , Child , Child, Preschool , Cost-Benefit Analysis , Humans , Quality-Adjusted Life Years , Vaccination
8.
PLoS Comput Biol ; 17(1): e1008470, 2021 01.
Article in English | MEDLINE | ID: mdl-33411742

ABSTRACT

Finding medications or vaccines that may decrease the infectious period of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could potentially reduce transmission in the broader population. We developed a computational model of the U.S. simulating the spread of SARS-CoV-2 and the potential clinical and economic impact of reducing the infectious period duration. Simulation experiments found that reducing the average infectious period duration could avert a median of 442,852 [treating 25% of symptomatic cases, reducing by 0.5 days, reproductive number (R0) 3.5, and starting treatment when 15% of the population has been exposed] to 44.4 million SARS-CoV-2 cases (treating 75% of all infected cases, reducing by 3.5 days, R0 2.0). With R0 2.5, reducing the average infectious period duration by 0.5 days for 25% of symptomatic cases averted 1.4 million cases and 99,398 hospitalizations; increasing to 75% of symptomatic cases averted 2.8 million cases. At $500/person, treating 25% of symptomatic cases saved $209.5 billion (societal perspective). Further reducing the average infectious period duration by 3.5 days averted 7.4 million cases (treating 25% of symptomatic cases). Expanding treatment to 75% of all infected cases, including asymptomatic infections (R0 2.5), averted 35.9 million cases and 4 million hospitalizations, saving $48.8 billion (societal perspective and starting treatment after 5% of the population has been exposed). Our study quantifies the potential effects of reducing the SARS-CoV-2 infectious period duration.


Subject(s)
COVID-19 Drug Treatment , COVID-19/transmission , Models, Biological , Pandemics , SARS-CoV-2 , COVID-19/epidemiology , COVID-19 Vaccines/therapeutic use , Computational Biology , Computer Simulation , Humans , Pandemics/prevention & control , Pandemics/statistics & numerical data , SARS-CoV-2/drug effects , Time Factors , United States/epidemiology , Virus Shedding/drug effects
9.
Am J Prev Med ; 59(4): 493-503, 2020 10.
Article in English | MEDLINE | ID: mdl-32778354

ABSTRACT

INTRODUCTION: Given the continuing COVID-19 pandemic and much of the U.S. implementing social distancing owing to the lack of alternatives, there has been a push to develop a vaccine to eliminate the need for social distancing. METHODS: In 2020, the team developed a computational model of the U.S. simulating the spread of COVID-19 coronavirus and vaccination. RESULTS: Simulation experiments revealed that to prevent an epidemic (reduce the peak by >99%), the vaccine efficacy has to be at least 60% when vaccination coverage is 100% (reproduction number=2.5-3.5). This vaccine efficacy threshold rises to 70% when coverage drops to 75% and up to 80% when coverage drops to 60% when reproduction number is 2.5, rising to 80% when coverage drops to 75% when the reproduction number is 3.5. To extinguish an ongoing epidemic, the vaccine efficacy has to be at least 60% when coverage is 100% and at least 80% when coverage drops to 75% to reduce the peak by 85%-86%, 61%-62%, and 32% when vaccination occurs after 5%, 15%, and 30% of the population, respectively, have already been exposed to COVID-19 coronavirus. A vaccine with an efficacy between 60% and 80% could still obviate the need for other measures under certain circumstances such as much higher, and in some cases, potentially unachievable, vaccination coverages. CONCLUSIONS: This study found that the vaccine has to have an efficacy of at least 70% to prevent an epidemic and of at least 80% to largely extinguish an epidemic without any other measures (e.g., social distancing).


Subject(s)
Communicable Disease Control , Computer Simulation , Coronavirus Infections , Pandemics , Pneumonia, Viral , Vaccination , Viral Vaccines/pharmacology , Betacoronavirus/isolation & purification , COVID-19 , COVID-19 Vaccines , Communicable Disease Control/methods , Communicable Disease Control/statistics & numerical data , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Disease Eradication/methods , Disease Eradication/statistics & numerical data , Humans , Needs Assessment , Pandemics/prevention & control , Pneumonia, Viral/epidemiology , Pneumonia, Viral/prevention & control , SARS-CoV-2 , Treatment Outcome , United States/epidemiology , Vaccination/methods , Vaccination/statistics & numerical data , Vaccination Coverage , Viral Vaccines/standards
10.
medRxiv ; 2020 May 30.
Article in English | MEDLINE | ID: mdl-32511569

ABSTRACT

BACKGROUND: Given the continuing coronavirus disease 2019 (COVID-19) pandemic and much of the U.S. implementing social distancing due to the lack of alternatives, there has been a push to develop a vaccine to eliminate the need for social distancing. METHODS: In 2020, we developed a computational model of the U.S. simulating the spread of COVID-19 coronavirus and vaccination. RESULTS: Simulation experiments revealed that when vaccine efficacy exceeded 70%, coverage exceeded 60%, and vaccination occurred on day 1, the attack rate dropped to 22% with daily cases not exceeding 3.2 million (reproductive rate, R0, 2.5). When R0 was 3.5, the attack rate dropped to 41% with daily cases not exceeding 14.4 million. Increasing coverage to 75% when vaccination occurred by day 90 resulted in 5% attack rate and daily cases not exceeding 258,029when R0 was 2.5 and a 26% attack rate and maximum daily cases of 22.6 million when R0 was 3.5. When vaccination did not occur until day 180, coverage (i.e., those vaccinated plus those otherwise immune) had to reach 100%. A vaccine with an efficacy between 40% and 70% could still obviate the need for other measures under certain circumstances such as much higher, and in some cases, potentially unachievable, vaccination coverages. CONCLUSION: Our study found that to either prevent or largely extinguish an epidemic without any other measures (e.g., social distancing), the vaccine has to have an efficacy of at least 70%.

11.
J Infect Dis ; 222(7): 1138-1144, 2020 09 01.
Article in English | MEDLINE | ID: mdl-32386323

ABSTRACT

BACKGROUND: The protection that an influenza vaccine offers can vary significantly from person to person due to differences in immune systems, body types, and other factors. The question, then, is what is the value of efforts to reduce this variability such as making vaccines more personalized and tailored to individuals. METHODS: We developed a compartment model of the United States to simulate different influenza seasons and the impact of reducing the variability in responses to the influenza vaccine across the population. RESULTS: Going from a vaccine that varied in efficacy (0-30%) to one that had a uniform 30% efficacy for everyone averted 16.0-31.2 million cases, $1.9-$3.6 billion in direct medical costs, and $16.1-$42.7 billion in productivity losses. Going from 0-50% in efficacy to just 50% for everyone averted 27.7-38.6 million cases, $3.3-$4.6 billion in direct medical costs, and $28.8-$57.4 billion in productivity losses. Going from 0-70% to 70% averted 33.6-54.1 million cases, $4.0-$6.5 billion in direct medical costs, and $44.8-$64.7 billion in productivity losses. CONCLUSIONS: This study quantifies for policy makers, funders, and vaccine developers and manufacturers the potential impact of efforts to reduce variability in the protection that influenza vaccines offer (eg, developing vaccines that are more personalized to different individual factors).


Subject(s)
Disease Transmission, Infectious/prevention & control , Epidemics , Influenza Vaccines/administration & dosage , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Cost-Benefit Analysis , Female , Humans , Infant , Infant, Newborn , Influenza Vaccines/economics , Influenza Vaccines/immunology , Influenza, Human/economics , Male , Middle Aged , Models, Statistical , Pharmacies , Seasons , Treatment Outcome , United States/epidemiology , Vaccination/economics , Vaccination Coverage , Young Adult
12.
Obesity (Silver Spring) ; 28(7): 1317-1324, 2020 07.
Article in English | MEDLINE | ID: mdl-32378341

ABSTRACT

OBJECTIVE: The study aim was to help the Girl Scouts of Central Maryland evaluate, quantify, and potentially modify the Girl Scouts Fierce & Fit program. METHODS: From 2018 to 2019, our Public Health Informatics, Computational, and Operations Research team developed a computational simulation model representing the 250 adolescent girls participating in the Fierce & Fit program and how their diets and physical activity affected their BMI and subsequent outcomes, including costs. RESULTS: Changing the Fierce & Fit program from a 6-week program meeting twice a week, with 5 minutes of physical activity each session, to a 12-week program meeting twice a week with 30 minutes of physical activity saved an additional $84,828 ($80,130-$89,526) in lifetime direct medical costs, $81,365 ($76,528-$86,184) in lifetime productivity losses, and 7.85 (7.38-8.31) quality-adjusted life-years. The cost-benefit of implementing this program was $95,943. Based on these results, the Girl Scouts of Central Maryland then implemented these changes in the program. CONCLUSIONS: This is an example of using computational modeling to help evaluate and revise the design of a program aimed at increasing physical activity among girls.


Subject(s)
Exercise/physiology , Research Design/trends , Simulation Training/methods , Adolescent , Female , Humans , Women
13.
Health Aff (Millwood) ; 39(6): 927-935, 2020 06.
Article in English | MEDLINE | ID: mdl-32324428

ABSTRACT

With the coronavirus disease 2019 (COVID-19) pandemic, one of the major concerns is the direct medical cost and resource use burden imposed on the US health care system. We developed a Monte Carlo simulation model that represented the US population and what could happen to each person who got infected. We estimated resource use and direct medical costs per symptomatic infection and at the national level, with various "attack rates" (infection rates), to understand the potential economic benefits of reducing the burden of the disease. A single symptomatic COVID-19 case could incur a median direct medical cost of $3,045 during the course of the infection alone. If 80 percent of the US population were to get infected, the result could be a median of 44.6 million hospitalizations, 10.7 million intensive care unit (ICU) admissions, 6.5 million patients requiring a ventilator, 249.5 million hospital bed days, and $654.0 billion in direct medical costs over the course of the pandemic. If 20 percent of the US population were to get infected, there could be a median of 11.2 million hospitalizations, 2.7 million ICU admissions, 1.6 million patients requiring a ventilator, 62.3 million hospital bed days, and $163.4 billion in direct medical costs over the course of the pandemic.


Subject(s)
Coronavirus Infections/economics , Disease Outbreaks/economics , Health Care Costs/statistics & numerical data , Health Resources/economics , Hospital Costs/statistics & numerical data , Pandemics/economics , Pneumonia, Viral/economics , COVID-19 , Delivery of Health Care/economics , Disease Outbreaks/statistics & numerical data , Female , Health Resources/statistics & numerical data , Humans , Intensive Care Units/economics , Intensive Care Units/statistics & numerical data , Length of Stay/economics , Male , Monte Carlo Method , Pandemics/statistics & numerical data , United States
14.
Am J Prev Med ; 57(3): 355-364, 2019 09.
Article in English | MEDLINE | ID: mdl-31353163

ABSTRACT

INTRODUCTION: There are several recommendations advising caregivers when and how to introduce solid food to infants. These complementary feeding guides vary in terms of the recommendations for timing and portions. The objective of this study is to determine the impact of following different guidelines on weight trajectories of infants. METHODS: In 2018, the study team developed a computational simulation model to capture feeding behaviors, activity levels, metabolism, and body size of infants from 6 months to 1 year. Daily food intake of virtual infants based on feeding recommendations translated to changes in body weight. Next, simulations tested the impact of the following complementary feeding recommendations that provided amount, type, and timing of foods: Children's Hospital of Philadelphia, Johns Hopkins Medicine, Enfamil, and Similac. RESULTS: When virtual caregivers fed infants according to the four different guides, none of the simulated situations resulted in normal weight at 12 months when infants were also being breastfed along average observed patterns. Reducing breast milk portions in half while caregivers fed infants according to complementary feeding guidelines resulted in overweight BMIs between 9 and 11 months for Children's Hospital of Philadelphia, Johns Hopkins Medicine, and Enfamil guidelines. Cutting breast milk portions in half also led to infants reaching unhealthy underweight BMI percentiles between 7 and 11 months for female and male infants when caregivers followed Children's Hospital of Philadelphia, Johns Hopkins Medicine, and Similac guidelines. CONCLUSIONS: This study identified situations in which infants could reach unhealthy weights, even while following complementary feeding guidelines, suggesting that current recommended portion sizes should be tightened.


Subject(s)
Body Mass Index , Breast Feeding/statistics & numerical data , Infant Nutritional Physiological Phenomena/standards , Models, Biological , Body Weight/physiology , Computer Simulation , Exercise/physiology , Feeding Behavior/physiology , Female , Guidelines as Topic , Humans , Infant , Infant, Newborn , Male , Overweight/diagnosis , Overweight/epidemiology , Overweight/etiology , Philadelphia , Thinness/diagnosis , Thinness/epidemiology , Thinness/etiology
15.
Vaccine ; 37(17): 2356-2368, 2019 04 17.
Article in English | MEDLINE | ID: mdl-30914223

ABSTRACT

INTRODUCTION: The lack of specific policies on how many children must be present at a vaccinating location before a healthcare worker can open a measles-containing vaccine (MCV) - i.e. the vial-opening threshold - has led to inconsistent practices, which can have wide-ranging systems effects. METHODS: Using HERMES-generated simulation models of the routine immunization supply chains of Benin, Mozambique and Niger, we evaluated the impact of different vial-opening thresholds (none, 30% of doses must be used, 60%) and MCV presentations (10-dose, 5-dose) on each supply chain. We linked these outputs to a clinical- and economic-outcomes model which translated the change in vaccine availability to associated infections, medical costs, and DALYs. We calculated the economic impact of each policy from the health system perspective. RESULTS: The vial-opening threshold that maximizes vaccine availability while minimizing costs varies between individual countries. In Benin (median session size = 5), implementing a 30% vial-opening threshold and tailoring distribution of 10-dose and 5-dose MCVs to clinics based on session size is the most cost-effective policy, preventing 671 DALYs ($471/DALY averted) compared to baseline (no threshold, 10-dose MCVs). In Niger (median MCV session size = 9), setting a 60% vial-opening threshold and tailoring MCV presentations is the most cost-effective policy, preventing 2897 DALYs ($16.05/ DALY averted). In Mozambique (median session size = 3), setting a 30% vial-opening threshold using 10-dose MCVs is the only beneficial policy compared to baseline, preventing 3081 DALYs ($85.98/DALY averted). Across all three countries, however, a 30% vial-opening threshold using 10-dose MCVs everywhere is the only MCV threshold that consistently benefits each system compared to baseline. CONCLUSION: While the ideal vial-opening threshold policy for MCV varies by supply chain, implementing a 30% vial-opening threshold for 10-dose MCVs benefits each system by improving overall vaccine availability and reducing associated medical costs and DALYs compared to no threshold.


Subject(s)
Cost-Benefit Analysis , Immunization Programs/economics , Measles Vaccine/economics , Measles/epidemiology , Measles/prevention & control , Models, Theoretical , Vaccination/economics , Algorithms , Humans , Measles Vaccine/administration & dosage , Measles Vaccine/immunology , Vaccination/methods
16.
Vaccine ; 37(4): 637-644, 2019 01 21.
Article in English | MEDLINE | ID: mdl-30578087

ABSTRACT

BACKGROUND: Frequently, a country will procure a single vaccine vial size, but the question remains whether tailoring the use of different size vaccine vial presentations based on populations or location characteristics within a single country could provide additional benefits, such as reducing open vial wastage (OVW) or reducing missed vaccination opportunities. METHODS: Using the Highly Extensible Resource for Modeling Supply Chains (HERMES) software, we built a simulation model of the Zambia routine vaccine supply chain. At baseline, we distributed 10-dose Measles-Rubella (MR) vials to all locations, and then distributed 5-dose and 1-dose MR vials to (1) all locations, (2) rural districts, (3) rural health facilities, (4) outreach sites, and (5) locations with average MR session sizes <5 and <10 children. We ran sensitivity on each scenario using MR vial opening thresholds of 0% and 50%, i.e. a healthcare worker opens an MR vaccine for any number of children (0%) or if at least half will be used (50%). RESULTS: Replacing 10-dose MR with 5-dose MR vials everywhere led to the largest reduction in MR OVW, saving 573,892 doses (103,161 doses with the 50% vial opening threshold) and improving MR availability by 1% (9%). This scenario, however, increased cold chain utilization and led to a 1% decrease in availability of other vaccines. Tailoring 5-dose MR vials to rural health facilities or based on average session size reduced cold transport constraints, increased total vaccine availability (+1%) and reduced total cost per dose administered (-$0.01) compared to baseline. CONCLUSIONS: In Zambia, tailoring 5-dose MR vials to rural health facilities or by average session size results in the highest total vaccine availability compared to all other scenarios (regardless of OVT policy) by reducing open vial wastage without increasing cold chain utilization.


Subject(s)
Computer Simulation , Immunization Programs , Measles Vaccine/supply & distribution , Rubella Vaccine/supply & distribution , Vaccines/supply & distribution , Child , Costs and Cost Analysis , Geography , Health Personnel , Humans , Measles/prevention & control , Measles Vaccine/economics , Refrigeration , Rubella/prevention & control , Rubella Vaccine/economics , Vaccination/economics , Vaccination/statistics & numerical data , Vaccines/economics , Zambia
17.
Vaccine ; 37(4): 645-651, 2019 01 21.
Article in English | MEDLINE | ID: mdl-30578088

ABSTRACT

BACKGROUND: Microneedle patch (MNP) technology is designed to simplify the process of vaccine administration; however, depending on its characteristics, MNP technology may provide additional benefits beyond the point-of-use, particularly for vaccine supply chains. METHODS: Using the HERMES modeling software, we examined replacing four routine vaccines - Measles-containing vaccine (MCV), Tetanus toxoid (TT), Rotavirus (Rota) and Pentavalent (Penta) - with MNP versions in the routine vaccine supply chains of Benin, Bihar (India), and Mozambique. RESULTS: Replacing MCV with an MNP (5 cm3-per-dose, 2-month thermostability, current single-dose price-per-dose) improved MCV availability by 13%, 1% and 6% in Benin, Bihar and Mozambique, respectively, and total vaccine availability by 1% in Benin and Mozambique, while increasing the total cost per dose administered by $0.07 in Benin, $0.56 in Bihar and $0.11 in Mozambique. Replacing TT with an MNP improved TT and total vaccine availability (3% and <1%) in Mozambique only, when the patch was 5 cm3 and 2-months thermostable but increased total cost per dose administered by $0.14. Replacing Rota with an MNP (at 5-15 cm3-per-dose, 1-2 month thermostable) improved Rota and total vaccine availability, but only improved Rota vaccine availability in Bihar (at 5 cm3, 1-2 months thermostable), while decreasing total vaccine availability by 1%. Finally, replacing Penta with an MNP (at 5 cm3, 2-months thermostable) improved Penta vaccine availability by 1-8% and total availability by <1-9%. CONCLUSIONS: An MNP for MCV, TT, Rota, or Penta would need to have a smaller or equal volume-per-dose than existing vaccine formulations and be able to be stored outside the cold chain for a continuous period of at least two months to provide additional benefits to all three supply chains under modeled conditions.


Subject(s)
Drug Delivery Systems , Microinjections , Transdermal Patch , Vaccination/methods , Vaccines/administration & dosage , Vaccines/supply & distribution , Benin , Costs and Cost Analysis , Humans , Immunization Programs , India , Influenza Vaccines/administration & dosage , Influenza Vaccines/supply & distribution , Mozambique , Refrigeration , Rotavirus Vaccines/administration & dosage , Rotavirus Vaccines/supply & distribution , Tetanus Toxoid/administration & dosage , Tetanus Toxoid/supply & distribution
18.
Vaccine ; 36(46): 7054-7063, 2018 11 12.
Article in English | MEDLINE | ID: mdl-30340884

ABSTRACT

INTRODUCTION: During an influenza epidemic, where early vaccination is crucial, pharmacies may be a resource to increase vaccine distribution reach and capacity. METHODS: We utilized an agent-based model of the US and a clinical and economics outcomes model to simulate the impact of different influenza epidemics and the impact of utilizing pharmacies in addition to traditional (hospitals, clinic/physician offices, and urgent care centers) locations for vaccination for the year 2017. RESULTS: For an epidemic with a reproductive rate (R0) of 1.30, adding pharmacies with typical business hours averted 11.9 million symptomatic influenza cases, 23,577 to 94,307 deaths, $1.0 billion in direct (vaccine administration and healthcare) costs, $4.2-44.4 billion in productivity losses, and $5.2-45.3 billion in overall costs (varying with mortality rate). Increasing the epidemic severity (R0 of 1.63), averted 16.0 million symptomatic influenza cases, 35,407 to 141,625 deaths, $1.9 billion in direct costs, $6.0-65.5 billion in productivity losses, and $7.8-67.3 billion in overall costs (varying with mortality rate). Extending pharmacy hours averted up to 16.5 million symptomatic influenza cases, 145,278 deaths, $1.9 billion direct costs, $4.1 billion in productivity loss, and $69.5 billion in overall costs. Adding pharmacies resulted in a cost-benefit of $4.1 to $11.5 billion, varying epidemic severity, mortality rate, pharmacy hours, location vaccination rate, and delay in the availability of the vaccine. CONCLUSIONS: Administering vaccines through pharmacies in addition to traditional locations in the event of an epidemic can increase vaccination coverage, mitigating up to 23.7 million symptomatic influenza cases, providing cost-savings up to $2.8 billion to third-party payers and $99.8 billion to society. Pharmacies should be considered as points of dispensing epidemic vaccines in addition to traditional settings as soon as vaccines become available.


Subject(s)
Disease Transmission, Infectious/prevention & control , Epidemics , Influenza Vaccines/administration & dosage , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Pharmacies , Vaccination/methods , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Cost-Benefit Analysis , Female , Humans , Infant , Infant, Newborn , Influenza Vaccines/economics , Influenza Vaccines/immunology , Influenza, Human/economics , Male , Middle Aged , Models, Statistical , Treatment Outcome , United States/epidemiology , Vaccination/economics , Vaccination Coverage , Young Adult
19.
Vaccine ; 36(39): 5879-5885, 2018 09 18.
Article in English | MEDLINE | ID: mdl-30146404

ABSTRACT

INTRODUCTION: By pairing diluent with vaccines, dual-chamber vaccine injection devices simplify the process of reconstituting vaccines before administration and thus decrease associated open vial wastage and adverse events. However, since these devices are larger than current vaccine vials for lyophilized vaccines, manufacturers need guidance as to how the size of these devices may affect vaccine distribution and delivery. METHODS: Using HERMES-generated immunization supply chain models of Benin, Bihar (India), and Mozambique, we replace the routine 10-dose measles-rubella (MR) lyophilized vaccine with single-dose MR dual-chamber injection devices, ranging the volume-per-dose (5.2-26 cm3) and price-per-dose ($0.70, $1.40). RESULTS: At a volume-per-dose of 5.2 cm3, a dual-chamber injection device results in similar vaccine availability, decreased open vial wastage (OVW), and similar total cost per dose administered as compared to baseline in moderately constrained supply chains. Between volumes of 7.5 cm3 and 26 cm3, these devices lead to a reduction in vaccine availability between 1% and 14% due to increases in cold chain storage utilization between 1% and 7% and increases in average peak transport utilization between 2% and 44%. At the highest volume-per-dose, 26 cm3, vaccine availability decreases between 9% and 14%. The total costs per dose administered varied between each scenario, as decreases in vaccine procurement costs were coupled with decreases in doses administered. However, introduction of a dual-chamber injection device only resulted in improved total cost per dose administered for Benin and Mozambique (at 5.2 cm3 and $0.70-per-dose) when the total number of doses administered changed <1% from baseline. CONCLUSION: In 3 different country supply chains, a single-dose MR dual-chamber injection device would need to be no larger than 5.2 cm3 to not significantly impair the flow of other vaccines.


Subject(s)
Injections/instrumentation , Measles Vaccine/administration & dosage , Rubella Vaccine/administration & dosage , Vaccination/instrumentation , Benin , Costs and Cost Analysis , Equipment and Supplies, Hospital , Freeze Drying , Humans , Immunization Programs/economics , India , Measles Vaccine/economics , Mozambique , Refrigeration , Rubella Vaccine/economics , Vaccination/economics
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