The recently published topic page on dose per container (DPC) provides a range of useful resources from case studies to decision support documents to better understand the effects of DPC on six immunization system components; namely operational costs, timely coverage, safety, wastage, and policy/correct use.   The Dose Per Container Partnership (DPCP) is excited to share these resources and hope that you will find them useful in your work with the immunization system as a whole. We encourage you to share your thoughts with us to continue the conversation on DPC.

Most of the countries now have improved immunization coverages and reach more children with vaccination, but we still need to monitor the potency of vaccines that are given on top of the high coverages we have achieved in many countries. One of the biggest challenges when we talk about vaccine potency is the storage condition and to be more specific “the storage temperature”. Most of the vaccines are either heat or freeze sensitive and we need to monitor the storage temperatures more closely so that we can have potent vaccines given to the children and hence achieve higher coverages with potent vaccines. There are several technologies that are currently applied in monitoring temperature of cold chain eg. VVM, Fridge and Freeze Tags, different types of RTM devices are now coming up. All this aimed at ensuring vaccines are stored in correct temperature to maintain potency. But, with all those devices the human component is not replaced and we still need someone to act upon the alarms or signs from those devices to ensure correct temperature are maintained all the time in vaccine cold chain. Based on the field experiences (9+ years) in immunization program, I am still not sure if the closed vial wastage due to freezing for freeze sensitive vaccines reflect the reality. That means, I doubt there are many children who are probably receive vaccines which have been exposed to freezing. We are very good in monitoring heat exposure because of VVM and we have observed closed vial wastage due to VVM change reported but freezing exposure is very difficult to monitor especially in the scenario when the facility does not use temperature monitoring devices that gives freezing alarms. The actions taken following low temperature excursion at the facility level makes me more worried and I feel there is a need of looking at this issue with an additional eye. Currently, many countries are getting into the new technologies of temperature monitoring but in some countries the coverage is still low. We may be proud of our improvement in the global immunization coverages but may be many of those kids are vaccinated with vaccines that are exposed to freezing. Being proud of the improvement of the global immunization coverages is good but we need to be confident that we have improved coverages with potent vaccines that are kept in recommended storage conditions. Use of modern technologies and innovations around temperature monitoring while working to improve immunization coverages is very important and this should off-course go hand in hand with behavior change on acting upon temperature excursion among those who are involved in vaccine cold chain.

AWAY WITH THE DOGMA! 1: “Monitoring Closed Vial Wastage”   This is the first Blog in a series to encourage vaccine supply chain planners to consider changes without being constrained by some, dogmatic operational policies of the Expanded Program on Immunization. Taking one issue at a time I shall explain its origin, why it is no longer helpful and suggest alternatives for us to debate.   So please, open the attached file and I look forward to your frank reactions!

Three years after the freeze-free concept was reported at the September 2014 meeting of the WHO PQS Committee, the current expectation of availability remains ‘sometime next year’ and it appears that no product has passed the pre-qualification (E004/VC02-VP.1) testing yet. The current status of this product was presented at the last Technet Conference by WHO/PQS. During the resulting discussion, I noted five issues that seem to require attention: The outside dimensions and weight of the current prototype products are greater than the carriers used for forty years. We should see comparative data on dimensions, weight of the new and existing carriers because health workers will carry them, often for long distances. Evidence that the increased weight and bulk is operationally feasible should be confirmed by field testing. Freeze-protection in current carrier designs employs a built-in thermal buffer between icepacks and vaccines. The vaccine carrier including the thermal buffer begins the PQS test at +43C when the vaccine load is added at +5C. Evidence was not shared at the Technet meeting that in fact the new products can cool down the test load to below +10C within 8 hours and what is the maximum temperature during cool down? WHO mentioned, in the context of fixed thermostat refrigerators, that replacement of existing equipment by new models will proceed at a ‘natural’ replacement rate under GAVI CCEOP. If this method of replacement is also followed for vaccine carriers that often survive for 10 years, the renewal process will be too slow to avoid a considerable rate of freezing damage. One question raised at Technet has been raised without a satisfactory answer many times in the last 3 years: “Why is the freeze-free carrier the only solution pursued by global stakeholders”. For example, freezers that deliver their frozen icepacks at a few degrees below zero instead of -20C are feasible, but not explored. Phase change materials as a substitute for water/icepacks have been rejected by PQS without clear evidence. The current PQS focus on passive cooling vaccine carriers with icepacks is likely to be overtaken by active-cooled solutions based on adsorption or thermoelectric technology. This solution, in the form of Global Good’s ‘Indigo’ product, gives outreach teams 5 days or more autonomy and streamlines the process of daily short range activities by switching cooling on and off. In spite of these benefits the product has no specification nor pre-qualification test in PQS because it is an active cooler, not passive. The current process for establishing a new product is said to be more than two years. These questions among others reveal a weakness in the way that the global immunization community handles technology changes for immunization services. Innovation and optimization are treated as ‘solutions hunting for a problem’ instead of operational challenges to the development and growth of immunization – that call for new or improved technologies. Your opinions on how WHO/PQS might strengthen and accelerate this process will be, i I am sure, very welcome !

Dear viewers Short supply of vaciines requiring multiple doses is one of the causes of accentuating negeative dropout rate, making the indicator invalid for programme review. India introduced two fractional doses of 0.1mL intra-dermal IPV in the National Immunization Schedule (NIS) since April 2016 as an end game strategy of Polio Eradication. It is supplied as multi dose vial of 50 doses per vial [0.1mL per dose – 5mL vial] & 25 doses [0.1mL per dose – 2.5mL]. From the first experiences of the first 5 vials we learnt that 61.6% doses were sacrificed [154 doses were sacrificed out of 250 doses in 5 vials]. Soon we received 25 doses per vial and the wastage became NIL [0%] in the CHC and Medical College. This month we again got 50 doses per vial. With this, to minimize “sacrificing” of precious vaccine and being supported by the midlevel managers, 3 Aces [ANMs, AWWs and ASHAs] stared mobilizing all those who are below one year and missed IPV due to short supply. With this ‘movement’ of clearing the backlog to close population immunity gap & to make optimum use of the vaccine, we observed that first dose IPV administered along with 3rd dose of OPV and Pentavalent was recorded in the ‘cell’ meant for IPV 2nd dose. This will give an accentuated negative IPV1 & IPV2 dropout. India is unique for unity in diversity. In the past, similar errors occurred when OPV supply was inadequate in 2012 in Jharkhand. Solution: Sustained Supportive Supervision, hands on orientation, learning by doing and working together approach by the supervisors, technical assistants and development partners goes a long way in quality data maintenance and programme implementation. The attached illustration is shared and the viewers may get similar observations in the field.  Regards Holla and the team  

Dear viewers - sharing the following for needful Universally it is very well known that vaccination is one of the most cost effective public health programme from control to eradication of Vaccine Preventable diseases. Public sector is provided with proper cold chain equipments, periodic training blended with monitoring & supportive supervision. National Immunization Schedule (NIS) is expanding; included IPV, Rota, MR, JE and Pneumococcal is the next candidate vaccine. Vaccines of NIS have Vaccine Vial Monitor (VVM). Optional vaccines applicable to our country [Meningococcal, Seasonal Influenza, Hepatitis A, Varicella, Typhoid, HPV for females] without VVM are easily available and accessible to the affordable. Availability of vaccines in various combinations: [Triple / Quadri / Penta….]; no uniform Immunization schedule created confusion among parents. Service providers in the tertiary care centers also have confusion / difference of opinion. Pilot study conducted among Medicos [undergraduate students / post graduates / faculties] revealed dangerously low operational knowledge about routine immunization. Absence of regular monitoring / supportive supervision; periodic training of private service providers have further accentuated the quality of vaccination service; e.g. Hepatitis B birth dose vaccine is yet to be started in some of the reputed pioneer Medical Colleges and in private clinics / hospitals. To address some of these issues, COMBOCARD was developed and shared, communicated with Govt, IAP and other stakeholders. Withdrawal of current IAP schedule by the IAP President [Ref:TOI] and assurance of issuing revised schedule is a welcome step provided the entire country will follow uniform schedule compatible with NIS. Sustaining >85% coverage of optional vaccines solely by the private sector is impossible without which community may not benefit “herd immunity”. The study also revealed that administering vaccine with known potency is not the task responsibility of private service provider. To create more awareness, simplified PPT on 8 rights before vaccine administration based on CDC guidelines and GoI guidelines was shared with the stakeholders. Proper cold chain equipment has an extremely important role in administering vaccines in potent condition which is seriously lacking in the private sector in India including private Medical Colleges. For solving this issue, “VaccineSafe” is designed and developed for the private service providers. Very few units are in use in Karnataka since 2005 due to lack of bulk manufacturer. Manufacturing locally in sufficient number incurs low cost and can solve the problem of private practitioners. With this in view, “VaccineSafe” Vs Conventional ILR with illustrations in 2 pages is attached for needful by the policymakers / global RI players / manufacturers of ILR / Pharmaceutical fridge.

Dear viewers - Please find the following and the attached illustration for a critical review and needful. Background: CCH Mrs Anitha Beth and Asst CCH Mr Mukesh could not believe when the author shared his observations that the “T” series vaccines were found in “Frozen” condition at the session site far off from the ILR point. Temperature record book never showed subzero recording on any day. CCH had to distribute vaccines to ~50 session sites on Thursdays and ~30 session sites on Saturdays. In a hurry, unconditioned icepacks were loaded in one of the vaccine carriers at about 7 AM and reached outreach at about 10 AM. Jerky movement during the excursion hastens the process of freezing. All vaccination service providers are aware that frozen “T” series vaccines lose potency and the precipitated particles act as foreign body and may result in cold sterile abscess. As per the formal training, vaccine vials are to be kept in a Ziploc pouch and placed in the vaccine carrier packed with 4 conditioned ice-packs. In northern states of India, with more than 2Lakh population per planning unit and ~300 outreach sessions per month, often / accidentally unconditioned ice-packs may be placed as in the above instance. Other common / frequent observations were unclean vaccine carrier, ill fitting lid, no strap to keep the lid in-situ, tampered vaccine carrier, vaccine vials without label, VVM in discard stage, wrong diluent or no diluent, only BCG/Measles/MR/JE, no dropper, only OPV, diluent outside the cold chain in the vanity bag, no starting date on vaccine vials of Open Vial Policy [MDVP] and the like. And now: Recently, on 21st April 2017, a senior consultant from New Delhi also being directed by his superiors from an international RI development partner agency visited the dedicated vaccination clinic of our KVG Medical College to address above issues, especially to avoid freezing of vaccines in the vaccine carrier while transporting. In response to this I wish to share the following, practicing in all the 3 Planning Units attached to our college with illustrations. Transparent plastic container has a screw cap, tapering towards the bottom and is icepack height. Holes are made using heated tip of piston of 2mL glass syringe for sustaining uniform temperature both inside and outside the plastic container within the vaccine carrier. However; inspite of training, orientation, re-orientation; passionate Sustained supportive supervision is indispensable, helps in hands on training, maintains perfection of the programme. Anticipated benefit: Apart from ensuring delivery of quality vaccine, this incurs negligible expenditure, aesthetic, easy to operate and can save millions of $ on operational research of designing new generation vaccine carrier. Sharing with the viewers for comments / sharing their experiences in this field.

Vaccines can tolerate temperatures above 8 deg C however temperatures below 0 deg C will freeze a vaccine and it will lose it’s efficacy. At temperatures above 8 deg C the life of a vaccine will be lowered but the exposure will not be catastrophic. For the most sensitive vaccine, VVM II, the life of the vaccine will decrease from 104 days to 99 days when exposed to 20 deg C conditions for one day. For a VVM7 vaccine exposed to the same one day temperature excursion the life of the vaccine will decrease from 650 days to 643 days. As Umit points out in a recent post [High Temperature Freezers], it is sometimes logistically difficult to get ice packs conditioned for an early morning departure. SDD freezers do not cool at night and as a consequence in the morning the ice packs are conditioned or close to being conditioned. Similarly, if an ice pack carrier is loaded with ice packs the night before a trip the ice packs will be conditioned or near conditioned the next morning. If the ice packs are not completely conditioned, they could be placed in the carrier earlier in the day to increase conditioning time. [b]Crowd Testing[/b] If a reader is involved in vaccine distribution this technique can easily be tested. In the afternoon, cold ice packs would be placed in a carrier along with a thermometer. The next morning the temperature of the carrier would be recorded and the ice packs examined. Water in the ice packs indicate that the ice packs are conditioned. It is most critical that the ice packs closest to the vaccines are fully conditioned. If the ice packs are not conditioned, repeat the experiment with the ice packs placed in the carrier earlier in the day. If, for example, the ice packs are conditioned 5 extra hours over the minimum conditioning time to reach 0 deg C, the consequence would be minimal. The length of time acceptable temperatures are maintained would be only reduced by 5 hours. Using “Crowed Testing” the effectiveness of this technique could be easily determined. If you are involved in the distribution of vaccines, I would appreciate your help in evaluating this method. Please send your answers to the following questions to Tech Net Name Location Date Model of carrier Number and size of packs in carrier Ice pack freezer temperature Number of hours in carrier over night Average ambient night time temperature Temperature of the carrier in the morning Is there water in the ice packs? Do you estimate more or less time is needed for conditioning? Comments

Does anyone have experience with vaccine passive storage devices in the field? We are piloting the PQS pre-qualified Arktek device in three rural health centers. By design, the device maintains a temperature range between 0°C and 10°C which will not freeze the vaccines so should not pose any risk to the potency of the vaccines. We are seeing some unease from health workers and EPI managers, though, who are concerned that vaccines would be out of the 2°C – 8°C range and at risk of freezing, even though all the evidence shows this type of passive storage device will not freeze vaccines when following proper procedures for conditioning the ice. On the one hand, this reaction from the health workers speaks to the success of training and insistence on good temperature control between 2 and 8°C. On the other hand, this new technology requires changes to standard operating procedures that have not been fully vetted with stakeholders and still require education and updating. Has anyone else had experience with this? Any suggestions on how to approach these types of changes to procedures required for this new technology? I appreciate any thoughts. Wendy

Knowing the problem of vaccines being frozen because of too cold ice-packs. What about freezers that does not get colder that minus 5'C

For your reading pleasure (and viewing since there is a 1 minute video)

Most ice-lined refrigerators in India are fully functional at 5 - 45 degrees Celsius (ie, they are able to maintain an internal temperature of 2-8 degrees Celsius when the external temperatures are between 5 and 45 degrees Celsius). Some states of India have an extremely cold climate during winters (for example, the areas of Jammu and Kashmir, Uttarakhand, Sikkim that are in the Himalayas) and so they are prone to high rates of vaccine freezing.
I am sure this is a problem experienced by program managers of Russia, Canada, Greenland, Iceland, northern Europe, Alaska, etc and would be extremely grateful if they could share how they have managed to tackle this in their respective countries/regions.
The only resource that I have been able to find till now after an extensive search is "The Warm Chain", which suggests the use of a low ambient temperature refrigerature which provides protection upto -5 degrees Celsius.Does WHO have any guidelines regarding this?
A related question would be - how do we arrange for outreach immunization in such cold climates? What sort of ice packs should be used in such a scenario?
Warm Regards,
Dr. Tapas Sadasivan Nair

The WHO UNICEF immunization Supply Chain Hub (iSC Hub)has released a new temperature monitoring website hosted on TechNet-21.
A stringent system for temperature surveillance is essential to maintain the quality of the vaccines in an effective Supply Chain. By preventing vaccine exposure to freezing or hot temperatures in the cold chain, a functioning temperature monitoring system helps ensuring vaccine potency, avoiding both wasting vaccine investments (notably through reducing closed vial wastage) and potentially placing children at risk of contracting vaccine preventable diseases.
This new areaof the TechNet-21 website stresses that effective surveillance depends on the development of a system of accountabilities, processes and equipment (in this order or importance) in order to ensure that temperature excursions are detected and that appropriate corrective measures are taken to avoid damage to the vaccines.
This website presents technical and programmatic information on available solutions to maintain vaccines in adequate temperature range at fixed storage and brings forward country experiences both on the use of 30DTR devices and RTM technologies. It aims at:

Providing decision makers and stakeholders with pragmatic step-by-step guidance and material to build a Temperature Monitoring system;
Encouraging experience sharing in order to leverage good practices and useful tools among countries and partners wanting to introduce or to update systematic temperature monitoring based on some of the technologies described.

You can access the website through the following link: http://www.technet-21.org/en/resources/temperature-monitoring
We hope you will find it useful and look forward to any feedback you may have.

Adama E. Sawadogo
Lead of the iSC Hub Strategic Focus Area
On temperature monitoring

Dose per Container Partnership (DPCP)
The issue: Multi-dose containers are used to offer lower prices, higher supply volumes, and minimize cold chain storage and distribution requirements. As new, more expensive, vaccines are introduced in multi-dose presentations, maximizing the use of every dose in a container increases in importance. HCWs need to be more strategic about when to open a container; diligent about how they care for open containers, and potentially more active with communication and community outreach to ensure optimal attendance and timely vaccination of every child. Thus, the number of doses per container (DCP) may also impact on health systems in terms of timely, safe and equitable vaccination coverage, supply and cold chain, wastage rates, cost and HCW behavior.
Immunization stakeholders need information and tools to assess which dose per container presentations are appropriate for a country’s specific context and priorities.
Initial 2015 response: With Bill & Melinda Gates Foundation (BMGF) funding, JSI Research & Training Institute, Inc. (JSI) helped identify evidence gaps by interviewing key stakeholders and analyzing existing research. An informal network of partners interested in advancing this work was created after a consultative meeting in July 2015.
Launch of the partnership: The Dose Per Container Partnership (DPCP) was launched in March 2016 as a project, funded by the BMGF and implemented by JSI in partnership with PATH, Agence de Médecine Préventive (AMP), Clinton Health Access Initiative (CHAI), HERMES modeling team and the International Vaccine Access Center (IVAC) / Johns Hopkins University. The DPCP aims to address the complexity of vaccine product and program decision-making to include DPC considerations. Understanding and assessing the trade-offs between cost and health impact allows better informed decisions about the impact of the dose per container selected.
DPCP objectives and work streams: The DPCP project will run from February 2016 – December 2017, guided by a Technical Advisory Group (TAG), and aims to achieve two objectives:
i) To gain a deeper understanding of the decision making processes, trade-offs, data
and tools used to assess DPC decisions at global and national levels in order to recommend process improvements;
ii) To provide guidance and tools including trade-offs to be considered by countries and facilitate
sharing of best practices for country level decision makers.
These will be implemented through three technical work streams:

A global cross-country review of current DPC-related decision making tools and processes;
Prospective research studies in two African countriesl will include data collection to improve modeling efforts, economic analysis and see the actual effect on the various systems variables; and
Synthesis of data supporting global level policy and country decisions.


Stakeholders: DPCP aims to inform, support and influence stakeholders at:
a) Global level, by providing evidence that fills critical gaps in knowledge, analysis, and policy. This includes ensuring that stakeholders will continue to be informed about sustainable decisions on DPC when considering vaccine products and program designs; and
b) Country level, by producing easy-to-use and -understand guides and tools to assess DPC tradeoffs, including cost and systems impact to inform vaccine product selection
Information about the DPCP will be made available through partners engaged with the project, the JSI website, announcements via the technet forum and various formal and informal opportunities where immunization practitioners meet globally, regionally or nationally.
http://jsi.com/JSIInternet/IntlHealth/project/display.cfm?ctid=na&cid=na&tid=40&id=22641

A recent article on vaccine wastage from the International Journal of Community Medicine and Public Health http://www.ijcmph.com/?mno=214575 Abstract Background: India released its first National Vaccine Policy in 2011. The country is presently developing new strategies to increase immunization coverage and reach more children with quality vaccine. High vaccine wastage increase vaccine demand and inflate overall program cost. Methods: This was records based descriptive study carried out at Immunization Clinic, Sardar Patel Medical College, Bikaner, Rajasthan. The information regarding vaccine vials used at Immunization Clinic and children vaccinated were retrieved from Immunization register for the reference period 1st April 2014 to 31st March 2015. Results: Among individual vaccine, wastage factor and rates was highest (1.42 and 29.45% respectively) for Oral Polio Vaccine (OPV) and lowest (1.10 and 9.21% respectively) for Hepatitis-B vaccine. The wastage rate for multi-dose vial was 27.66% for 5 doses vial, 13.88% for 10 doses vial and highest 29.45% for 20 doses vials. Among vaccines wastage rate of lyophilized vaccines (23.30%) were higher when compared to liquid vaccines (20.66%). Conclusions: Vaccine wastage rate can be obtained by monitoring of the immunization centre. Monitoring vaccine wastage will help not only to improve quality of the programme but it will also increase the efficiency of the programme. This can thus help save significant funds for an immunization programme.

Immunization outreach services depend on a protective, affordable and efficient supply chain to benefit rather than obstruct outreach operations. Four potential cold-chain solutions are on offer but each has barriers to be negotiated or removed. The options are: Frozen water packs BUT we should switch to freeze-free vaccine carriers to avoid the risk of freezing: Vaccines certified for use in a ‘Controlled Temperature Chain’: PCM-filled packs used in all existing carriers and boxes prevent freezing BUT pending resolution of cost and other issues by WHO. So, which of the 3 solutions interests you most? Do you know of others? I await your views and look forward to a lively discussion! (See the attachment!)

Potency of vaccine at the time of administration to the beneficiaries is of utmost importance in preventing morbidity and mortality due to vaccine preventable diseases. Evolution of more and more vaccines against crippling and lethal diseases has made vaccination the most cost-effective and important strategy from control to eradication. Domestic refrigerators with horizontally opening vertical door is not recommended by WHO for keeping vaccines for certain reasons leading to excess“temperature excursions”.However, it appears that the storage code is not evolved enough to make the best use of the right equipment (ILR) recommended by the WHO. Since I had problems responding to some of the questions asked by the vaccine / cold chain handlers, I am sharing these questions with the cold chain specialists for addressing the same.

“Apps” (computer software applications) are being developed and used as tools to help manage the vaccines and medicines supply chain more and more. But are they directed at challenges that have persisted the longest and would have the greatest impact if resolved? Take, for example, the following two challenges; do you recognise them? Do you agree that they need to be addressed or do you believe that they have been addressed in your country (ies) and that other should be chosen? Challenge 1: Most health centres in the world keep a wall chart with a manual plot of the percent of surviving infants fully immunized during the calendar year. As each month passes the cumulative coverage reached is amended for that month indicating visually the performance of the service relative to the target population(s) in that year. This works until the coverage approaches 80-90% when the cumulative coverage plot is high and the marginal changes in the last three months of the year are quite small. Then it is hard to read the performance impact in the last months of the year and hard to assess visually the changes since last year. Solution 1: The number of people receiving each vaccine dose, each month is already kept in a database for the national immunization reporting system. So it will not require more data or more work to change the monthly coverage value from the cumulative coverage for the current year to date - to the total coverage for the last, running twelve months (this year and a part of last). Now the plot is a true ‘annual’ coverage measure for every month of the year, reflecting what has been achieved and what has still to be achieved correctly and visually. Challenge 2: The rate at which vaccine has been consumed at the level of service delivery over one or more of the most recent supply intervals, corrected for planned changes in target population or vaccine presentation, remains the most practical basis for calculating vaccine needs for the next supply period. The problem is that this arithmetic, while simple, takes no account of seasonal differences, wastage variations or migration movements historically or trends over the years. Where the changes in consumption are small or gradual, the current method works but when the change is important and rapid it no longer prevents stock-out. Solution 2: The consumption of vaccine (comprises the number of doses in opened vials that have been used or wasted for any reason) is already accessible via vaccine stock records kept by computerized stock control at district level. The aggregate number of doses for the whole zone for each vaccine and each month should be used by an application to forecast vaccine needs for the next supply period, adjusted for any vaccine or system changes planned for the next period. An application will do the necessary arithmetic and aggregation, adjusting for later reporting.   The resulting Dashboard in each district can also present the rates of vaccine utilization (Vaccine administered as % of vaccine consumed). Closed vaccine wastage, as a part of vaccine consumed needs to be analysed only when there is an overall problem of utilization rate, not simply monitored without site investigation.

The budget impact of controlling wastage with smaller vials: A data driven model of session sizes in Bangladesh, India (Uttar Pradesh), Mozambique, and Uganda. W Yang, M Parisi, B Lahue, J Uddin, D Bishai - Vaccine, 2014 Link to full Article. http://www.sciencedirect.com/science/article/pii/S0264410X14013358 Highlights This model was the first of its kind to generate wastage rates as an output based on country-level micro data collected at different types of clinics in the field. A demographics-based budget impact model with a ten-year analytical horizon was developed. The model estimated vaccine wastage rate and its economic implications for Inactive polio vaccine, based on arrival distributions derived from field data of session sizes in Bangladesh, India (Uttar Pradesh), Mozambique, and Uganda. Our study demonstrated that while wastage reduction can be realized by switching to smaller dose vials, it did not guarantee a reduction in total program costs. With the flexibility of our model design, it can be adapted to different vaccines prices and dose schedules, which enables policy makers to weigh different factors in optimal vaccine delivery decision making.