Vaccine Vial Monitor Research Articles

Gaps in vaccine management practices during vaccination outreach sessions in rural settings in southwestern Uganda

BackgroundOutreach efforts were developed to bolster people’s access to and use of immunization services in underserved populations. However, there have been multiple outbreaks of diseases like measles in Uganda, prompting policy makers and stakeholders to ask many unanswered questions. This research study was created to uncover the discrepancies between vaccine management practices at immunization outreach sessions in rural South Western Uganda compared with existing standards.MethodsThe observational qualitative study, was done in 16 public health facilities across four districts of Uganda. Data were collected using in-depth interviews, facility record reviews, and observation. We assessed the vaccine management procedures before immunization session, transportation used, set up at the outreach site, management practices during the outreach session and packing of vaccines - according to World Health Organization immunization practice recommendations. The data were transcribed, coded and categories were formed and triangulated. Themes were generated based on a socio-ecologic framework to gain a better understanding of healthcare provider practices during immunization sessions.ResultsFifty-one individuals were interviewed; four Assistant District Health Officers, four cold chain technicians, 15 focal persons for the Expanded Program on Immunization, and 28 health care providers. The respondents’ mean age was 35, 43 (84.3%) were females and 24 (47.1%) had a diploma. 11 (69%) outreaches were conducted at a distance of 5-12 km from the health facility and 7 (44%) were conducted in a building. For 8 outreaches (50%) health facility staff did not check the vaccine vial monitor status before the outreach while 12(75%) did not keep the vaccine hard lid cover closed during the sessions. The main areas of concern were insufficient vaccine integrity monitoring, improper handling and storage practices, deficient documentation, and inadequate vaccine transportation. These were similar across immunization outreach sites regardless of vaccine preventable disease outbreaks occurrences. The majority of these gaps were located at the individual level but were enabled by policy/environmental factors.ConclusionsThere are poor vaccine management procedures during outreach sessions contrary to established guidelines. Specific tactics to tackle knowledge deficiencies, health worker attitude, and fewer equipment shortages could improve compliance to guidelines.

Stability of lyophilized Meningococcal A conjugate vaccine, (MenAfriVac™) at elevated temperatures to support controlled temperature chain (CTC) claim

Meningococcal A Conjugate Vaccine (MenAfriVac) is the world’s first Monovalent Conjugate Vaccine against Neisseria Meningitidis serogroup A which has obtained Controlled Temperature Chain (CTC) label claim of “stable upto 40°C for 4 days prior to reconstitution” developed by Serum Institute of India Pvt. Ltd. Pune, India and the vaccine was granted permission from World health Organization. This paper elucidates and talks about the layout of various studies performed to characterize the product to declare as CTC at the time when the knowledge and mechanism to describe CTC was not fully known which in term helped to design the CTC guidelines.Product stability was assessed using clinical, consistency and regular lots released by NRA. The critical stability indicating parameters like free polysaccharide, molecular size distribution along with Potency and safety tests were carried out to support the product stability making sure it also qualifies for Vaccine Vial Monitor label claim of VVM30. An additional in use stability (reconstitution) was also performed. All studies indicated that the product remains stable at real time as well as elevated temperatures and well within the specifications approved by NRA and formed the strong basis for CTC claim which is now recommended by WHO.

Antivenoms, hepatitis B vaccine and oral polio vaccine can be considered for storage and handling outside the cold chain following the innovative ‘controlled temperature chain’ approach

Possible applicability of controlled temperature chain (CTC) for selected antisera and vaccines was evaluated. Bivalent oral polio vaccine (OPV), hepatitis B vaccine (HepB vaccine; monovalent and combined) and antisera (lyophilized and liquid scorpion-antivenom and liquid snake-antivenom) were tested. Samples were stored at accelerated (35 ± 5 °C) and freezing (−25 ± 5 °C) conditions for 24 h, one week and one month in addition to recommended storage condition (2–8 °C), except OPV samples that were tested at accelerated and refrigerated (2–8 °C) conditions compared to recommended storage conditions (−25 ± 5 °C). All samples were tested for potency. Protein content and composition were determined for antisera samples. All vaccine vial-monitors were evaluated. HepB vaccine was subjected to aluminum-content assay, shake test and microscopical examination. No significant change in antisera potency was detectable under accelerated condition for a week. OPV stored in refrigerator for a month and at accelerated condition for 48 h maintained acceptable potency. Monovalent and combined HepB vaccine maintained acceptable potency under accelerated condition for a month and a week, respectively. Freezing adversely affected HepB vaccine. In conclusion, reevaluation of storage conditions of tested products is urgently required; this can reduce storage costs and improves their availability. Other products should be tested for possible CTC applicability.

Evaluation on monitoring effect of the electronic vaccine vial monitor label

The cold chain safety of vaccines is a global issue. The electronic vaccine vial monitor (eVVM) label can monitor the temperature of vaccines in real time and provide "early warning" prompts. In order to comprehensively evaluate the monitoring efficiency of eVVM, this study selected 75 eVVM labels and distributed them with a total of 600 vaccine vial monitor (VVM) labels of four different types in different experimental environment (2-8℃, -20℃ and 40℃), and used a temperature recorder as "gold standard". The results showed that the accuracy of the eVVM labels and VVM labels in high temperature environment was as same as that of the temperature recorder ( P = 0.195). The accuracy of low temperature anomalies report and high temperature anomalies report of eVVM labels was 100%, which was better than those reported by VVM labels. Therefore, eVVM labels have high monitoring accuracy, which is suitable not only for ordinary environments, but also for severe temperature environments. It should be helpful for the improvement of the efficiency and accuracy of cold chain monitoring.

Application of the remaining vaccine vial monitor life calculation to field temperature monitoring data to improve visibility into cold chain equipment performance

Vaccine Vial Monitors (VVM) are used to estimate if a vaccine has been exposed to excessive hot temperatures. This endpoint measurement is useful in determining if a vaccine is safe to be administered to a patient, but it does not pinpoint where in the cold chain a vaccine was exposed to excessive heat. With the expansion and technological advancement of cold chain equipment temperature monitoring, it is now possible to remotely estimate VVM status as a vaccine moves through the cold chain. In the present study, we examine the application of the mathematical principles backing VVMs on real, continuous, temperature monitoring data in Africa. Results suggest that exposure to short bursts of hot temperature or long power outages may still allow for safe distribution of affected vaccines. The remaining VVM life calculation could improve managerial visibility into cold chain equipment performance allowing for better data-driven planning and maintenance decisions.

A vaccine cold chain temperature monitoring study in the United Mexican States

Vacine cold chain assessments conducted in various parts of the world indicate that maintaining equipment at the temperature range recommended by the World Health Organization (WHO) is not always observed. It has been also the case that staff rather prioritize protecting vaccine from heat damage, thus often exposing vaccines to freezing temperatures. As a result, inadvertent freezing of vaccines is a largely overlooked problem all over the world. In a recent systematic review, comparison of the occurrence of freezing temperatures during storage and transport were found to be a global problem occurring both in the resource-rich as well as the resource-limited settings. A vaccine cold chain temperature monitoring study was conducted using standard WHO study protocol with the objective to document potential problems and to identify appropriate control measures. Multiple temperature monitoring devices were used in the study to evaluate user friendliness of these devices and staff attitudes towards them. In general, majority of the time, temperatures were kept between recommended temperature range of 2–8 °C. Temperature variation got wider when products moved from 3PL Laboratory to service points. The wider variation is found at the service points. High temperature excursions were observed or short periods of time while exposures to freezing temperatures were more both higher in number and duration, however, shake test with these vaccines indicated no freeze damage. 91% of staff believed that they did not have the necessary tools to detect if a vaccine had been damaged by a temperature excursion outside the 2–8 °C range, and all staff believed that inclusion of such devices (e.g. vaccine vial monitor) in the system would improve cold chain operations as they have became aware of problematic areas through this study.

Vaccine Vial Monitor Based Vaccine Management: An Albania Experience

Vaccine vial monitor (VVM) stands out amongst all the temperature monitoring devices and tools, as the only one that has shaped the course of vaccine management practices as well as the vaccine cold chain. Some critical vaccine management approaches that are practiced today, such as multi-dose vial policy, and controlled temperature chain have only been made possible with the help of VVM, and others such as rotating stocks and dispatches have been made more effective. Using the Albania immunization programme as a case, this paper reviews the vaccine management practices from the VVM perspective.

A cross-sectional survey on awareness, practice of vaccine administration, and cold chain management in a tertiary health center of Western Maharashtra

Introduction: The potency of vaccines depends on maintaining the cold chain, that is, a prescribed temperature range during distribution from manufacture to use. The paramedical staff of any hospital plays a pivotal role in cold chain maintenance. Hence, the study aims to assess knowledge and practice of cold chain maintenance of vaccines by paramedical staff. Materials and Methods: A cross-sectional questionnaire-based study was conducted among paramedical staff in a tertiary health care of western Maharashtra, from June 15, 2019, to August 30, 2019. The data were collected using interview schedule. Results:A total of 115 paramedics were enrolled. The final data analysis was done on 91 respondents. Participants' knowledge about maintenance of refrigerators with respect to place of vaccine storage (54; 59.34%), temperature recording in a day (54; 59.34%), and preferable place of deep freezer (62; 68.13%) was satisfactory. A total of 42 (46.15%) participants had knowledge about shake test; however, only 38 (41.75%) participants knew about demonstration of shake test, suggesting that awareness about testing the frozen vaccine was poor among paramedical staff. Full form and use of vaccine vial monitor (VVM) in participants were satisfactory, being 70 (76.92%) and 59 (64.83%), respectively. Participant's knowledge about correct site and route of administration of vaccines were satisfactory. Conclusion: The study demonstrates the gap in knowledge in cold chain maintenance of the paramedical workers. Regular training may be conducted for the paramedical workers to improve their understanding of the cold chain management.

Vaccines distribution system at primary healthcares in the special region of Yogyakarta

Background: Vaccine cold-chain distribution system must be monitored to guarantee the vaccine quality. Improper vaccine distribution system can cause damage and loss of efficacy. Therefore, the Indonesian government released some regulations to manage the vaccine cold-chain system, including the Good Distribution Practices for Pharmaceutical Products (Cara Distribusi Obat yang Baik/CDOB) in 2012 and Regulation of the Minister of Health Number 42 in 2013 (PMK 42/2013). Objective: The purpose of this study was to evaluate the implementation of the vaccine distribution system in primary healthcare (PHCs). Methods: A survey was conducted in 30 PHCs in the Special Region of Yogyakarta. Data were collected by observing the vaccine distribution system in PHCs using checklists developed based on CDOB 2012 and PMK 42/2013. Results: The study showed that the personnel in 24 PHCs (80%) checked the condition of the temperature monitoring device and Vaccine Vial Monitor (VVM) while receiving the vaccines. Furthermore, all PHCs (100%) had both cool packs and vaccine carriers, whereas those having cold packs were only 2 (7%). First expired - first out (FEFO) and first in - first out (FIFO) systems were implemented in 30 (100%) and 28 (93%) PHCs, respectively. Conclusion: The results indicated that most of the PHCs in Yogyakarta Special Region had implemented a good vaccine distribution system, yet they still need improvement especially in vaccine recording procedures.

A cross sectional study to assess the functioning of cold chain in a tribal district of central India

Background: Immunization is one of the best efforts that India is putting forward currently to fight against various vaccine preventable diseases. Cold chain maintenance is always an issue. Therefore, cold chain maintenance is a pre-requisite in the correct delivery of immunization services.Methods: A cross sectional study was conducted among 18 cold chain points (CCPs) of Jhabua district using standard Government of India (GOI) structured questionnaires.Results: Out of 18 cold chain points only 5.55% had dry room for the storage of needle, syringes and other clerical material. A separate voltage stabilizer was attached each to deep freezer and ILR at only 22% of the health centers. Only 55.55% CCPs waste disposal pit constructed as per guideline. 94.45% cold chain handlers (CCHs) knew the definition of cold chain and correct temperature range at which vaccines to be stored, whereas only 33.33% CCHs knew about Shake test. 72.23% CCHs knew how to read vaccine vial monitor (VVM) and stages of VVM correctly. Knowledge of the CCHs regarding open vial policy was poor, with only 33.33% knowing exactly, the details of open vial policy.Conclusions: The quality of immunization programme can be increased by proper maintenance of cold chain and management of vaccine logistics at every designated cold chain point. There is need to improve the knowledge level of CCHs regarding cold chain maintenances and handling practices.

Challenges of cold chain quality for routine EPI in south-west Burkina-Faso: An assessment using automated temperature recording devices

BackgroundAbnormal temperatures are a major issue for vaccines within the Expanded Program of Immunization in tropical climates. Prolonged exposure to temperatures outside the standard +2 °C/+8 °C range can impact vaccine potency. MethodsThe current study used automatic temperature recording devices (Testostore 171-1©) to monitor cold chain in remote areas of Western Burkina Faso. A series of 25 randomly selected health centers representing 33% of the existing 176 EPI facilities in Western Burkina Faso were prospectively assessed for eight months in 2015. Automatic measurements were compared to routine temperature loggers and vaccine vial monitors (VVM). ResultsThe median age for all refrigerators was 9 years with 10/25 (42%) older than 10 years. Adverse temperatures were recorded in 20/24 (83%) refrigerators and ranged from −18.5 °C to +34.2 °C with 12,958/128,905 (10%) abnormal hourly records below +2 °C and 7357/128,905 (5.7%) above +8 °C. Time of day significantly affected the rate of temperature excursions, with higher rates from 00 am to 06 am (p < 0.001) for low temperatures and 10–12 am (p < 0.001) and 13–16 pm (p < 0.001) for high temperatures. Abnormal temperatures lasted from 1 h to 24 h below +2 °C and 13–24 h above +8 °C. Standard manual registers reported only 182/2761 (7%) inadequate temperatures and VVM color change detected only 133/2465 (5%) disruptions. Reliability of the refrigerators ranged from 48% to 98.7% with a median of 70%. Risk factors for excursions were old age of the refrigerators, the months of April and May, hours of high activity during the day, and health staff-associated factors such as inappropriate actions or insufficient knowledge. ConclusionImportant cold chain reliability issues reported in the current study in Western Burkina Faso raise concern about vaccine potency. In the absence of systematic renewal of the cold chain infrastructure or improved staff training and monitoring, antibody response assessment is recommended to study levels of effective immunization coverage.

The effect of cool water pack preparation on vaccine vial temperatures in refrigerators

Cool water packs are a useful alternative to ice packs for preventing unintentional freezing of vaccines during outreach in some situations. Current guidelines recommend the use of a separate refrigerator for cooling water packs from ambient temperatures to prevent possible heat degradation of adjacent vaccine vials. To investigate whether this additional equipment is necessary, we measured the temperatures that vaccine vials were exposed to when warm water packs were placed next to vials in a refrigerator. We then calculated the effect of repeated vial exposure to those temperatures on vaccine vial monitor status to estimate the impact to the vaccine. Vials were tested in a variety of configurations, varying the number and locations of vials and water packs in the refrigerator. The calculated average percentage life lost during a month of repeated warming ranged from 20.0% to 30.3% for a category 2 (least stable) vaccine vial monitor and from 3.8% to 6.0% for a category 7 (moderate stability) vaccine vial monitor, compared to 17.0% for category 2 vaccine vial monitors and 3.1% for category 7 vaccine vial monitors at a constant 5 °C. The number of vials, number of water packs, and locations of each impacted vial warming and therefore percentage life lost, but the vaccine vial monitor category had a higher impact on the average percentage life lost than any of the other parameters. The results suggest that damage to vaccines from repeated warming over the course of a month is not certain and that cooling water packs in a refrigerator where vaccines are being stored may be a useful practice if safe procedures are established.

Vaccine vial monitor availability and use in low- and middle-income countries: A systematic review

IntroductionThe vaccine vial monitor (VVM) registers cumulative heat exposure on vaccines over time. As low- and lower-middle-income countries transition beyond support from the Global Alliance for Vaccines and Immunization (Gavi), they will assume full responsibility for vaccine financing and procurement. It is unclear to what extent countries transitioning out of Gavi support will continue to include VVMs on their vaccines. This paper aims to systematically review evidence on VVM availability and use in low- and middle-income countries to document factors behind global access to and country demand for VVMs. Such results could help identify actions needed to ensure continued use of VVMs in countries that transition out of Gavi support. MethodsWe performed a systematic review of electronic databases, reference lists, and grey literature in English and French languages with publication dates from 2005 onwards. The studies included were analyzed for the following outcomes: (1) availability and deployment of VVM-labeled vaccines; (2) VVM practices and perceptions in the immunization system; (3) vaccine introduction and decision-making processes; (4) Gavi graduation and vaccine program sustainability. ResultsThe study found that VVM availability and use was affected by multiple sourcing of vaccines and the extent to which VVM was included in the vaccine specification in the tendering documents when procuring vaccines. Knowledge about VVM and its impact on the EPI program was found to be high among health workers as well as decision-makers. However, the study also found that weak capacity in key national institutions such as NRA and NPA might impact on demand for VVM. As countries take decisions regarding the adoption of new vaccines, factors such as disease burden and vaccine price may assume greater importance than vaccine characteristics and presentation. Finally, the study found that countries rely largely on the advice and recommendations from technical partners such as WHO and PAHO. ConclusionThe study concludes that global access to and country demand for VVM are dependent on policy statements and recommendations about VVM by key policy institutions such as WHO and UNICEF. The study also concludes that despite Gavi-eligible countries having access to VVM-labeled vaccines, inclusion is often below 100%. Weak institutional capacity in key national agencies such as NRA and NPA seems to be a contributing factor, while other factors include the procurement of clear national policies on the inclusion of VVM on vaccines, along with the capacity to enforce the policy. Finally, the study concludes that knowledge about VVM and its impact on vaccine program efficiency, safety, and cost is critical for transitioning countries’ continuous demand for VVM.

Knowledge assessment regarding poliomyelitis among the caregivers of children who received oral polio vaccine reveals lack of awareness of the vaccine vial monitor (VVM): Implications extending beyond polio eradication.

Vaccine vial monitor (VVM) is now commonly used for vaccines that are included in the National Immunization Schedule in India. It helps to indicate the viability of the vaccine and of the proper functioning of the cold chain. This is useful as it prevents health personnel from administering damaged vaccine. Studies have shown a lack of awareness of health workers regarding the use and interpretation of a VVM. The current study, undertaken among the caregivers of children who were immunized, showed that this lack of information about the VVM also exists among the caregivers. This deficiency in knowledge, both in the health workers and the caregivers, can affect the health of the child and needs urgent attention.

Assessment of maternal and child health services during Mamta days in urban areas of Surat City

Background: Mamta Divas is a fixed day, fixed site, preventive, and promotive health-care service center for mother and child population. Growth health checkup, immunization, primary treatment, referral, and counseling services are provided by FHW (Female Health Worker), ANM (Auxiliary Nurse Midwife) and AWW (Anganwadi Worker). Objective: To study the reproductive and child health services during Mamta days among the beneficiaries of health-care facility centers. Materials and Methods: It was a cross-sectional study conducted in 20 urban health centers of Surat Corporation Area from July 2012 to June 2013 by using pretested, semi-structured questionnaire for the assessment of maternal and child health services during the Mamta days. Result: In all sites it was noted that vaccine vial monitor of vials was in stage I or II, freeze-sensitive vaccines were in liquid form, vaccines have readable label, all vaccines were within expiry date, and all providers knew which vaccine cannot be reused. Information about follow-up date was provided in 94.59% session sites, followed by family planning advice in 67.57%, and nutrition advice in 60.81%. Breast-feeding assessment and examination were not done by them. Abdominal palpation was not performed in 88.52% of session sites because of lack of privacy as separate rooms and curtains were unavailable. Conclusion: Maternal and child health services were not provided satisfactorily in many session sites, therefore, training and retraining of health workers is required for better outcome.

Benefits of using vaccines out of the cold chain: Delivering Meningitis A vaccine in a controlled temperature chain during the mass immunization campaign in Benin

BackgroundIn October 2012, the Meningococcal A conjugate vaccine MenAfriVac was granted a label variation to allow for its use in a controlled temperature chain (CTC), at temperatures of up to 40°C for not more than four days. This paper describes the first field use of MenAfriVac in a CTC during a campaign in Benin, December 2012, and assesses the feasibility and acceptability of the practice. MethodsWe implemented CTC in one selected district, Banikoara (target population of 147,207; 1–29 years of age), across 14 health facilities and 150 villages. We monitored the CTC practice using temperature indicators and daily monitoring sheets. At the end of the campaign we conducted a face-to-face survey to assess vaccinators’ and supervisors’ experience with CTC. FindingsA mix of strategies were implemented in the field to maximize the benefits from CTC practice, depending on the distance from health centre to populations and the availability of a functioning refrigerator in the health centre. Coverage across Banikoara was 105.7%. Over the course of the campaign only nine out of approx. 15,000 vials were discarded due to surpassing the 4 day CTC limit and no vial was discarded because of exposure to a temperature higher than 40°C or due to the Vaccine Vial Monitor (VVM) reaching its endpoint. Overall confidence and perceived usefulness of the CTC approach were very high among vaccinators and supervisors. InterpretationVaccinators and supervisors see clear benefits from the CTC approach in low income settings, especially in hard-to-reach areas or where cold chain is weak. Taking advantage of the flexibility offered by CTC opens the door for the implementation of new immunization strategies to ensure all those at risk are protected.

Vaccine Storage and Handling Practices among routine immunization service providers in a metropolitan city of North-Central Nigeria

Background: The efficacy of vaccines can be compromised by faulty transport, storage, and handling. This study was conducted to assess the knowledge and practice of vaccine storage and handling among Primary Health Care Workers (PHCWs) offering routine immunization (RI) services in static health facilities in Ilorin metropolis, North-central Nigeria. Methodology: It was a descriptive cross-sectional study carried out among 457 Primary Health Care Workers (PHCWs) in 2 Local Government Authorities in Kwara State, north central Nigeria, using multi stage sampling technique. The research instruments were pretested self-administered questionnaire and observational checklist. The data generated were analyzed using EPI-INFO version 3.5.1 software package. Level of significance was predetermined at p-value of less than 0.05 at 95% confidence interval. Results: About half of the respondents (52.1%) knew the optimal vaccine storage temperature, 35.4% knew that freezing is harmful to certain vaccines. Although, 67.8% were aware of the 'shake test', only 48.4% of them knew how to conduct it. Up to 367 (80.3%) acknowledged that heat is harmful to vaccines. Even though, 267 (58.4%) knew the vaccine vial monitor (VVM) stages, only 248 (45.3%) could interpret the VVM correctly. About 30% of the health facilities (HFs) had adequate vaccine storage equipments while less than one third (28.6%) refrigerators were used exclusively for vaccine storage. However, functioning thermometers were present in all the refrigerators devoted to vaccine storage. Conclusions: Vaccine storage and handling practices among PHCWs providing routine immunization (RI) services in the study area was still sub-optimal. There is need for periodic on the job training and supportive supervision of health workers by middle cadre immunization officers in the local government to improve on the vaccine storage and handling practices of RI service providers. Keywords: Routine immunization, knowledge, vaccine handling, Nigeria, practices

Assessment of cold-chain maintenance in vaccine carriers during Pulse Polio National Immunization Day in a rural block of India.

India was certified polio free on 27 March 2014. Supplementary immunization activities, in the form of national immunization days, is one of the core strategies for eradication, where oral polio vaccine is administered to children aged under 5 years throughout the country. Oral polio vaccine is heat sensitive and requires maintenance of a stringent cold chain. Therefore, vaccine carriers with ice packs are used in the Pulse Polio Immunization (PPI) programme. This study assessed whether the cold chain is maintained during National Immunization Day in Beed district. A cross-sectional study was conducted at six randomly selected booths, one each from six primary health centres in Georai block of Beed district in Maharashtra. Electronic data loggers, configured to measure half-hourly temperatures, were kept in vaccine carriers throughout the day of PPI. The vaccine carrier temperature was below 8 °C at all six booths; minimum temperature recorded was -9.5 °C, while the maximum was 4.5 °C. The vaccine vial monitor did not reach discard point in any booth. A vaccine carrier with four ice packs very effectively maintains the cold chain required for oral polio vaccine.

The Potency of Yellow Fever Vaccines Sold in Open Markets in Eastern Nigeria

Background: There has been a re-emergence of Yellow Fever (YF) disease across Africa and in South America since the 1980s. According to WHO estimate, 508 million people in 32 countries are at risk because of their location in the rainforest region, the habitat of the vector mosquito.Intense YF virus circulation occurred in West Africa in 2008 and 2009 with outbreaks reported from Burkina Faso, Cameroon, Central African Republic, Chad, Congo, Cote d’Ivoire, Guinea, Liberia and Sierra Leone. Between January 2010 and March 2011, outbreaks of YF were reported to the WHO by Cameroon, Cote d’Ivoire, Democratic Republic of Congo, Sierra Leone, Senegal and Uganda. Most recent outbreaks in Africa were reported simultaneously in Ghanaand Cameroun on the 3rd of February, 2012.This study investigates a possible correlation between vaccine manufacture, cold chain handling and vaccine potency/ stability as a risk factor in the repeated outbreak of yellow fever in the face of increased immunisation coverage in Nigeria and West Africa by extension. Methods: Samples of Stamaril®, a yellow fever vaccine collected from different open market sources were subjected to potency test by measuring their immunogenicity indicators.Their embryo infectivity dose and mice LD50 as well as their pyrogenicity were determined. Results: Results showed that 42% of the vaccines tested were not suitable for use even though the vaccine vial monitor certifies they are fit for use. Conclusion: A large proportion of YF vaccines sold in open markets in Eastern Nigeria may be compromised in terms of potency. Vaccine vial monitors only are not entirely reliable as indicators of vaccine potency or usability.

A Cost Effectiveness and Capacity Analysis for the Introduction of Universal Rotavirus Vaccination in Kenya: Comparison between Rotarix and RotaTeq Vaccines

BackgroundDiarrhoea is an important cause of death in the developing world, and rotavirus is the single most important cause of diarrhoea associated mortality. Two vaccines (Rotarix and RotaTeq) are available to prevent rotavirus disease. This analysis was undertaken to aid the decision in Kenya as to which vaccine to choose when introducing rotavirus vaccination.MethodsCost-effectiveness modelling, using national and sentinel surveillance data, and an impact assessment on the cold chain.ResultsThe median estimated incidence of rotavirus disease in Kenya was 3015 outpatient visits, 279 hospitalisations and 65 deaths per 100,000 children under five years of age per year. Cumulated over the first five years of life vaccination was predicted to prevent 34% of the outpatient visits, 31% of the hospitalizations and 42% of the deaths. The estimated prevented costs accumulated over five years totalled US$1,782,761 (direct and indirect costs) with an associated 48,585 DALYs. From a societal perspective Rotarix had a cost-effectiveness ratio of US$142 per DALY (US$5 for the full course of two doses) and RotaTeq US$288 per DALY ($10.5 for the full course of three doses). RotaTeq will have a bigger impact on the cold chain compared to Rotarix.ConclusionVaccination against rotavirus disease is cost-effective for Kenya irrespective of the vaccine. Of the two vaccines Rotarix was the preferred choice due to a better cost-effectiveness ratio, the presence of a vaccine vial monitor, the requirement of fewer doses and less storage space, and proven thermo-stability.