Monovalent type 2 OPV (mOPV2) management in the field: Interventions and lessons learned.

The polio endgame strategy calls for ending the use of and removal of all Sabin vaccines globally given the risks of generation and spread of cVDPVs. With the successful eradication of wild poliovirus type 2 in 2015, the process of removing type 2 Sabin vaccines began with the switch from tOPV to bOPV across national vaccination programs. Following the tOPV to bOPV switch in April/May 2016, monovalent type 2 OPV (mOPV2) has been put into use in response to detected cVDPV2 polioviruses outbreaks. Between 31 May 2016 and 30 Jun 2020, 453 million doses of mOPV2 were provided to 21 countries to conduct 235 campaigns to respond to cVDPV2 outbreaks and high-risk events. However, the use of this vaccine paradoxically reintroduces live attenuated type 2 poliovirus into the populations and the environment, therefore, poses a risk for the emergence of new VDPV2s. Thus, it is critical to carefully and appropriately manage all in-country mOPV2 stocks utilized in outbreak response to minimize this risk. In this article, we examine the performance of mOPV2 vaccine management utilized for various outbreak responses after the switch.We present the major challenges faced and the lessons learned, to improve technical guidance and future response activities. Performance varied significantly across countries in terms of each of the activity areas evaluated. There were major gaps, especially in terms of vaccine accountability, and in many instances large numbers of vials went unaccounted presenting additional risk for further VDPV2 emergences. We have shown that especially at the beginning of implementation, insufficient attention has been given to mOPV2 vaccine management. Enhanced focus on mOPV2 vaccine management in line with the lessons learned presented in this paper should be a priority for public health programs and countries to consider and adapt in future VDPV2 responses as well as potential future activities associated with eventual complete withdrawal & cessation of OPV.These experiences can also be extended to other vaccines for which strict stock management and containment measures are required.

Mapathons versus automated feature extraction: a comparative analysis for strengthening immunization microplanning.

BACKGROUND: Social instability and logistical factors like the displacement of vulnerable populations, the difficulty of accessing these populations, and the lack of geographic information for hard-to-reach areas continue to serve as barriers to global essential immunizations (EI). Microplanning, a population-based, healthcare intervention planning method has begun to leverage geographic information system (GIS) technology and geospatial methods to improve the remote identification and mapping of vulnerable populations to ensure inclusion in outreach and immunization services, when feasible. We compare two methods of accomplishing a remote inventory of building locations to assess their accuracy and similarity to currently employed microplan line-lists in the study area. METHODS: The outputs of a crowd-sourced digitization effort, or mapathon, were compared to those of a machine-learning algorithm for digitization, referred to as automatic feature extraction (AFE). The following accuracy assessments were employed to determine the performance of each feature generation method: (1) an agreement analysis of the two methods assessed the occurrence of matches across the two outputs, where agreements were labeled as "befriended" and disagreements as "lonely"; (2) true and false positive percentages of each method were calculated in comparison to satellite imagery; (3) counts of features generated from both the mapathon and AFE were statistically compared to the number of features listed in the microplan line-list for the study area; and (4) population estimates for both feature generation method were determined for every structure identified assuming a total of three households per compound, with each household averaging two adults and 5 children. RESULTS: The mapathon and AFE outputs detected 92,713 and 53,150 features, respectively. A higher proportion (30%) of AFE features were befriended compared with befriended mapathon points (28%). The AFE had a higher true positive rate (90.5%) of identifying structures than the mapathon (84.5%). The difference in the average number of features identified per area between the microplan and mapathon points was larger (t = 3.56) than the microplan and AFE (t = - 2.09) (alpha = 0.05). CONCLUSIONS: Our findings indicate AFE outputs had higher agreement (i.e., befriended), slightly higher likelihood of correctly identifying a structure, and were more similar to the local microplan line-lists than the mapathon outputs. These findings suggest AFE may be more accurate for identifying structures in high-resolution satellite imagery than mapathons. However, they both had their advantages and the ideal method would utilize both methods in tandem.

Experiences and Lessons From Polio Eradication Applied to Immunization in 10 Focus Countries of the Polio Endgame Strategic Plan.

Nine polio areas of expertise were applied to broader immunization and mother, newborn and child health goals in ten focus countries of the Polio Eradication Endgame Strategic Plan: policy & strategy development, planning, management and oversight (accountability framework), implementation & service delivery, monitoring, communications & community engagement, disease surveillance & data analysis, technical quality & capacity building, and partnerships. Although coverage improvements depend on multiple factors and increased coverage cannot be attributed to the use of polio assets alone, 6 out of the 10 focus countries improved coverage in three doses of diphtheria tetanus pertussis containing vaccine between 2013 and 2015. Government leadership, evidence-based programming, country-driven comprehensive operational annual plans, community partnership and strong accountability systems are critical for all programs and polio eradication has illustrated these can be leveraged to increase immunization coverage and equity and enhance global health security in the focus countries.

Is there enough vaccine to eradicate measles? An integrated analysis of measles-containing vaccine supply and demand.

Responding to regional advancements in combating measles, the World Health Organization in May 2008 called for an assessment of the feasibility of measles eradication, including whether sufficient vaccine supply exists. Interviews with international health officials and vaccine-makers provided data for a detailed model of worldwide demand and supply for measles-containing vaccine (MCV). The study projected global MCV demand through 2025 with and without a global eradication goal. The study found that 5.2 billion MCV doses must be administered during 2010-2025 to maintain current measles programs, and 5.9 billion doses would likely be needed with a 2020 eradication goal; in the most intensive scenario, demand could increase to 7.5 billion doses. These volumes are within existing and planned MCV-manufacturing capacity, although there are risks. In some markets, capacity is concentrated: Supply-chain disruptions could reduce supply or increase prices. Mitigation strategies could include stockpiling, long-term contracts, and further coordination with manufacturers.