Classification of Vaccination PODs

Vaccine-administration POD layout types can be grouped into four types, namely traditional station-based sequential-flow (station-based), cell-based sequential-flow (cell-based), fixed-seat service, and pop-up PODs. An illustration of the classification is shown in Figure 2.

Figure 2. Illustrative Overview of Open POD Layout Types for Vaccination and Antibiotic Distribution: (A) Station-Based Vaccination POD. (B) Cell-Based Vaccination POD. (C) Fixed-Seat Service Vaccination POD. (D) Pop-Up Vaccination POD. (E) Sequential Processing of Antibiotic Distribution POD. (F) Selective Expedited Processing of Antibiotic Distribution POD. Abbreviation: POD, point of dispensing.

Station-based POD is characterized by a sequential progression through discrete stations, including reception, screening, vaccination, post-vaccination observation, and registration.^{Reference Kitro, Tippong and Sirikul10–Reference Wood, Murch and Moss13} A fundamental principle emphasized in such PODs is clear spatial delineation, which allows staff and visitors to understand the procedural flow easily. Conversely, cell-based POD retains the same overall sequence but involves consolidating multiple functions into integrated clinical cells. Core activities, such as screening and vaccination (usually with registration), occur within a single station, reducing unnecessary movements, shortening queues, and accelerating processing.^{Reference Smith and Smith9,Reference Signorelli, Odone and Gianfredi14–Reference Wood, Moss and Murch18} Comparative analyses indicated that the cell-based model outperformed the traditional station-based POD in efficiency, waiting time reduction, and spatial utilization. Smith, et al^{Reference Smith and Smith9} demonstrated that a large-scale COVID-19 vaccination center using a cell-based POD reduced the processing time (excluding post-vaccination observations) from 1,020 seconds to 400 seconds, achieving a 60.8% reduction.^{Reference Smith and Smith9} This improvement was attributed to fewer bottlenecks, enhanced collaboration among multidisciplinary staff, and the elimination of redundant tasks, such as repeated identity checks. Additionally, the cell-based design offered modularity, allowing each cell to operate as an independent unit, which could be scaled up or down according to the visitor volume, improving staff utilization.

The fixed-seat service POD differs fundamentally from sequential-flow types. Rather than requiring visitors to move between stations, individuals remain seated in assigned chairs while a mobile vaccination team, typically comprising a physician, two nurses, and administrative personnel, rotates among them to deliver all the necessary services.^{Reference Hsiao, Huang and Huang19} Hsiao, et al^{Reference Hsiao, Huang and Huang19} described an implementation in Taiwan’s Expo Dome where 18 parallel blocks each contained 84 seats, arranged in 3×28 rows with one-meter spacing for social distancing. Each team vaccinated 80-150 people per hour, with an average visitor stay of 25 minutes. In this model, the critical factor was the speed at which vaccination teams circulated, rather than visitor flow. This approach is visitor-centered, accommodating those with mobility limitations while naturally maintaining social distancing. However, continuous team movement can cause staff fatigue.

Pop-up POD is a small-scale, temporary vaccination site that focuses solely on vaccination while streamlining ancillary processes. Its compact design allows for rapid setup and relocation, making it suitable for communities where large-scale PODs are impractical.^{Reference Lawson, Clark and Geraghty20} The pop-up POD model, developed in the United States during the COVID-19 response, contrasted with the Federal Emergency Management Agency (FEMA; Washington, DC USA) standards, which required at least 43 staff members for 230m² and 17.3 minutes per vaccination. Conversely, the pop-up POD involved only 15 staff members at 210m² and achieved a two-minute vaccination time. Over 12 hours, a single site could vaccinate 720 individuals, far surpassing FEMA’s target of 250. This efficiency was achieved through several strategies, including integrating check-in with health screening, positioning syringe preparation assistants adjacent to vaccinators, decoupling vaccination registration from clinical tasks, and handling paperwork independently of visitor flow during and, when needed, after operating hours. Additional measures included deploying prepared supply kits at each station rather than relying on a central pharmacy.

Improvement Strategies for Each Step of the Vaccine-Administration POD Process

The process enhancement results are presented in Table 2. The unexpected influx of many visitors can cause bottlenecks throughout the process, leading to increased waiting times and difficulties in social distancing.^{Reference Smith and Smith9,Reference Jerbi and Masmoudi12,Reference Wood, Murch and Moss13,Reference Calegari, Bisesti and Pazzaglia16–Reference Wood, Moss and Murch18} Therefore, most studies controlled visitor numbers and flow rates through an appointment system. However, evidence supporting optimal appointment scheduling volumes during operating hours is lacking. To address this, Wood, et al^{Reference Wood, Moss and Murch18} used discrete-event simulations to calculate the optimal number of appointments based on the POD actual processing capacity. Their analysis revealed that the initial plan targeting 1,560 people per day caused severe bottlenecks during the vaccination phase, with queues growing continuously, rendering the actual operation unfeasible. Based on the simulation results, they recommended capping daily appointments at 1,247 and limiting vaccination staff members to six.

Table 2. Layout Types and Actual Operational Features of Vaccination Points of Dispensing (PODs)

Abbreviation: POD, point of dispensing.

Screening, a pre-vaccination medical assessment used to determine eligibility, typically takes one-to-ten minutes.^{Reference Smith and Smith9,Reference Kitro, Tippong and Sirikul10,Reference Jerbi and Masmoudi12–Reference Signorelli, Odone and Gianfredi14,Reference Sala, D’Urso and Giardini17,Reference Wood, Moss and Murch18} Two approaches are reported: (1) visitor self-assessment forms that are verified by staff, primarily used as an operational triage to route only those requiring medical consultation;^{Reference Le Bagousse-Bernard, Dussart and Pin11} and (2) clinician-led interviews in which health care personnel ask and record responses and make the eligibility decision directly.^{Reference Smith and Smith9,Reference Kitro, Tippong and Sirikul10,Reference Jerbi and Masmoudi12,Reference Signorelli, Odone and Gianfredi14–Reference Wood, Moss and Murch18} Using a self-questionnaire to triage patients, those not requiring medical consultation reached vaccination in a mean period of 12 minutes versus 16 minutes with consultation, with a four-minute reduction in the no-consultation group. Multi-stage pathways that required specialist review increased complexity and were associated with longer screening times (mean 12.2 minutes).^{Reference Kitro, Tippong and Sirikul10} In contrast, a single-step, clinician-led screening, supported by digital intake, demonstrated notably higher efficiency. Jerbi, et al^{Reference Jerbi and Masmoudi12} reported sub-one-minute screening times using a web-based questionnaire reviewed by the clinician. Overall, the evidence indicated that a one-pass clinician-led screening, which is optionally front-loaded with digital tools, was the most time-efficient approach.

Vaccination, the core step of vaccine POD, follows immediately after screening and typically takes two-to-three minutes per recipient.^{Reference Kitro, Tippong and Sirikul10,Reference Jerbi and Masmoudi12,Reference Wood, Murch and Moss13,Reference Sala, D’Urso and Giardini17,Reference Lawson, Clark and Geraghty20} Beyond the injection, this stage usually includes syringe preparation and brief post-vaccination counseling. To shorten the cycle time at the vaccination station, sites have implemented the following strategies: (1) seating two recipients per table to enable parallel preparation and rapid turnover; and (2) assigning vaccination assistants to handle dilution and syringe preparation, allowing vaccinators to focus solely on injections.^{Reference Kitro, Tippong and Sirikul10,Reference Jerbi and Masmoudi12,Reference Lawson, Clark and Geraghty20} Some types centralized dilution and syringe preparation in a dedicated area, such as a pharmacy-based prep room, supplying ready-to-use doses to each station and further reducing workload at the stations.^{Reference Le Bagousse-Bernard, Dussart and Pin11,Reference Signorelli, Odone and Gianfredi14,Reference Wood, Moss and Murch18}

Resources and Efficiency Metrics Used in Vaccine POD Operations

Although each study reported the resources used in vaccination operations, such as facility area, daily operating hours, total staff involved, and the total number of vaccinations administered per day, many studies have not clearly presented efficiency metrics, such as staff utilization rate, throughput per hour, throughput per vaccination staff per hour, and total time spent within the facility, limiting the ability to perform comparative analysis. Among the studies that reported efficiency metrics, the highest throughput per vaccination staff per hour was 31.6 for the station-based POD, 27.5 for cell-based POD, 26.7 for fixed-seat service, and 30.0 for pop-up POD types.^{Reference Jerbi and Masmoudi12,Reference Oliani, Savoia and Gallo15,Reference Hsiao, Huang and Huang19,Reference Lawson, Clark and Geraghty20} This indicates that vaccination staff members on average processed approximately one person every two minutes, which was close to the maximum efficiency, given that actual clinical vaccination typically takes approximately one-to-two minutes per person. Based on these results, it could be inferred that similar vaccination efficiency levels could be achieved regardless of the POD layout types. A thorough evaluation should incorporate additional metrics, including staff utilization and operational efficiency, in relation to the spatial dimensions of the facility. However, most studies lack basic operational information.

Classification of Antibiotic-Distribution PODs

In contrast to vaccination PODs, where medical interventions are conducted, antibiotic-distribution PODs primarily involve dispensing pre-determined antibiotic dosages, which reduces the need for medical personnel in the dispensing area. Furthermore, a post-vaccination observation zone is not required. The operational flow of an antibiotic-distribution POD comprises initial orientation, triage with health status assessment, detailed screening and medication determination, and medication dispensing.

The POD layout types reported in previous studies share broadly similar structures that can be categorized into two primary types, distinguished by whether a branched, expedited-dispensing stream is created at the entrance. In the sequential-processing POD, visitors proceed through a fixed series of steps after entry and are routed to a designated station for additional review when specific conditions are identified (eg, allergies, comorbidities, symptom onset, or the need for dose adjustment).^{Reference Stergachis, Wetmore and Pennylegion21–Reference Spitzer, Hupert and Duckart23} This model prioritizes accurate assessments and safety over speed. In the selective expedited-processing POD, simple cases are screened at the entrance, and eligible visitors are diverted to an expedited-dispensing line to improve the overall throughput.^{Reference Agócs, Fitzgerald and Alles24,Reference Kilianski, O’Rourke and Carlson25} Agocs, et al^{Reference Agócs, Fitzgerald and Alles24} directed visitors not requiring consultation or dose adjustment to an expedited line and reduced the median processing time to three minutes, compared with eight minutes on the general line. Conversely, Kilianski, et al^{Reference Kilianski, O’Rourke and Carlson25} sent visitors with mobility issues or symptoms to an expedited line and observed an average processing time of 3.24 minutes, which was shorter than the five-to-twelve minutes observed for the general route. An illustration of the classification is shown in Figure 2.

Improvement Strategies for Antibiotic-Distribution POD Processes

Strategies for improving the efficiency of each step in the antibiotic-distribution POD are summarized in Table 3. In contrast to vaccination PODs, studies on antibiotic distribution involved using an on-site registration process. To reduce the number of visitors and alleviate congestion, some PODs implemented a model in which the household head collected antibiotics on behalf of all family members.^{Reference Stergachis, Wetmore and Pennylegion21,Reference Agócs, Fitzgerald and Alles24,Reference Kilianski, O’Rourke and Carlson25} However, this approach had several limitations. First, the household head may not have fully understood the medication instructions for all family members. Second, the accuracy and completeness of the information relayed by household representatives may be compromised. Third, requiring each family member to complete self-screening questionnaires and consent forms can be time-consuming. However, most studies suggest that a family distribution model centered on the household head, if properly supplemented, would be more effective in speed and congestion management.

Table 3. Layout Types and Actual Operational Features of Antibiotic-Distribution Points of Dispensing (PODs)

Abbreviation: POD, point of dispensing.

At all PODs, visitors completed a standardized self-questionnaire in a designated area or while queuing, which was universally used as the basis for screening to determine the medication to dispense. Screening approaches are categorized into two types, namely a single-step approach (in which the medication decision is made in one pass) and a two-step approach (which escalates to expert consultation when additional judgment is needed). Previous studies did not report the specific screening times for single-step approaches. In two-step approaches, Spitzer, et al^{Reference Spitzer, Hupert and Duckart23} reported screening times of 10.2-19.8 seconds and 31.2 seconds for the first and second screening, respectively.

The dispensing area is operationally critical in antibiotic-distribution PODs. In practice, the distribution is commonly organized into separate streams. Stergachis, et al^{Reference Stergachis, Wetmore and Pennylegion21} routed visitors to color-coded lines after screening, as follows: green for standard adult doses, blue for pediatric suspensions, and orange for participants requiring dose adjustments owing to contraindications or comorbidities. Similarly, Doyle-Moss, et al^{Reference Doyle-Moss22} separated dispensing by assigning a primary area to pre-assigned standard antibiotics and a secondary area to nonstandard agents and suspensions. The principal advantage of this separation is improved accuracy and more rapid handoffs at each dispensing station. However, demand imbalances across streams can create line-specific bottlenecks that reduce the overall throughput.^{Reference Kilianski, O’Rourke and Carlson25}

Resources and Efficiency Metrics for Antibiotic-Distribution POD Operations

Similar to those of the vaccine-distribution POD studies, many efficiency metrics have not been reported in some cases, limiting direct comparisons between studies. Overall, the average time visitors spent from entry to exit ranged from six-to-ten minutes, and the total dispensing volume was approximately 250-1,000 units/hour. Notably, Agocs, et al^{Reference Agócs, Fitzgerald and Alles24} documented the highest throughput, dispensing to 1,060 individuals/hour, with 106 units/distributor/hour, in a selective expedited-processing POD using a household-head-centered family distribution model. They reported that simple paperwork minimization and a rule-based algorithmic screening workflow substantially amplified overall efficiency.^{Reference Agócs, Fitzgerald and Alles24}