The importance of supplementary immunisation activities to prevent measles outbreaks during the COVID-19 pandemic in Kenya.

BACKGROUND: The COVID-19 pandemic has disrupted routine measles immunisation and supplementary immunisation activities (SIAs) in most countries including Kenya. We assessed the risk of measles outbreaks during the pandemic in Kenya as a case study for the African Region. METHODS: Combining measles serological data, local contact patterns, and vaccination coverage into a cohort model, we predicted the age-adjusted population immunity in Kenya and estimated the probability of outbreaks when contact-reducing COVID-19 interventions are lifted. We considered various scenarios for reduced measles vaccination coverage from April 2020. RESULTS: In February 2020, when a scheduled SIA was postponed, population immunity was close to the herd immunity threshold and the probability of a large outbreak was 34% (8-54). As the COVID-19 contact restrictions are nearly fully eased, from December 2020, the probability of a large measles outbreak will increase to 38% (19-54), 46% (30-59), and 54% (43-64) assuming a 15%, 50%, and 100% reduction in measles vaccination coverage. By December 2021, this risk increases further to 43% (25-56), 54% (43-63), and 67% (59-72) for the same coverage scenarios respectively. However, the increased risk of a measles outbreak following the lifting of all restrictions can be overcome by conducting a SIA with ≥ 95% coverage in under-fives. CONCLUSION: While contact restrictions sufficient for SAR-CoV-2 control temporarily reduce measles transmissibility and the risk of an outbreak from a measles immunity gap, this risk rises rapidly once these restrictions are lifted. Implementing delayed SIAs will be critical for prevention of measles outbreaks given the roll-back of contact restrictions in Kenya.

Generalidades sobre las vacunas comercializadas en España: estudio monográfico de la vacuna contra el sarampión / Generalities of vaccines marketed in Spain: monographic study of the measles vaccine

INTRODUCCIÓN: la vacunación es, en la historia de la medicina, una de las actuaciones más significativas en la reducción de la mortalidad infantil y la erradicación de enfermedades. Sin embargo, con el apogeo de los denominados grupos "antivacunas" ha aumentado la incidencia de enfermedades infecciosas, entre ellas, el sarampión, cuya erradicación no ha sido posible para el año 2015, como había propuesto la Organización Mundial de la Salud. OBJETIVO: hemos estudiado diferentes aspectos tecnológicos de las vacunas comercializadas en España, centrándonos en las utilizadas contra el sarampión, y su problemática actual a la hora de su administración. MÉTODO: se ha realizado un estudio de las fichas técnicas de las vacunas recogidas en la Agencia Española de Medicamentos y Productos Sanitarios. RESULTADOS: se obtuvieron resultados sobre diferentes aspectos: tipo de vacuna, sistema fisicoquímico, forma farmacéutica, vía de administración y dispositivo para su administración. Además, se han analizado las formulaciones de las vacunas existentes contra el sarampión, haciendo hincapié en los diversos excipientes que contienen: estabilizadores, antibióticos, medios de cultivo, etc. CONCLUSIONES: la mayoría de las vacunas comercializadas en España se presentan en forma de suspensión para administración intramuscular o subcutánea mediante jeringa precargada. En el caso de la vacuna contra el sarampión, encontramos tres medicamentos de preparación extemporánea, que se presentan en forma de polvo liofilizado en vial y vehículo en jeringa precargada, producidas a partir de diferentes virus vivos o atenuados, siendo por tanto vacunas combinadas

INTRODUCTION: in the history of medicine, vaccination is one of the most important operations in the reduction of infant mortality and the eradication of diseases. However, with the apogee of the so-called “anti-vaccine” groups has increased the incidence of infectious diseases, including measles, whose erad¬ication is not possible by the year 2015, as the World Health Organization had proposed. Objective: we have studied different vaccines existing in the Spanish market available to health profes¬sionals and we have analyzed the formulations of existing measles vaccines. METHOD: the data sheets of different vaccines available to health professionals collected at the Spanish Agency of Medicines and Health Products has been studied. RESULTS: the results have been obtained from different aspects: type of vaccine, physicochemical system, pharmaceutical form, way of administration or device for its administration. In addition, we have an¬alyzed formulations of existing measles vaccines, by emphasizing different excipients which contain: stabilizers, antibiotics, culture media, etc. CONCLUSIONS: the majority of vaccines marketed in Spain are sus¬pensions, to be administered by an intramuscular or subcutaneous injection, with a pre-filled syringe. In the case of the measles vac¬cine, we found three drugs of extemporaneous preparation that are presented as lyophilized powder in vial and vehicle in a pre-filled syringe. They are produced from different live or attenuated virus¬es so they are combined vaccines

WebPalestra: Sarampo. Suspeita, manejo e prevenção

The impact of vaccine procurement methods on public health in selected European countries.

Introduction: Across Europe, immunization programs have brought immense benefits to the prevention of infectious diseases. The vaccines used are procured through a variety of models such as tenders and Pricing & Reimbursement. However, to date, the impact of the procurement method on the performance and sustainability of vaccination programs and on public health has received little attention.Areas covered: Drawing on a review of the academic and policy literature, complemented by an interview program with stakeholders involved in the procurement of vaccines, the authors have documented the relationship between procurement method dynamics and the level of protection against vaccine-preventable diseases in Germany, Italy, Spain and Romania for, measles-containing vaccines, hexavalent and influenza vaccines.Expert opinion: Price-based tenders can contribute to vaccine supply issues, discourage the provision of value-added services supporting vaccination coverage and disincentives future R&D. Although it is observed that price-based tenders can intensify competition in the short term, there can be unintended consequences such as damage to long-term competition. As European countries are committed to strengthen their immunization programs, they should consider the implications of current vaccine procurement models on the vaccine ecosystem and on public health.

The value of tailoring vial sizes to populations and locations.

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.

Actualización situacion sarampion y acciones intensificadas de vigilancia y control / Update to measles situation and intensified actions on surveillance and control

El 28 de marzo de 2018 se confirmó un caso de sarampión en un bebe de 8 meses, residente de la Ciudad de Buenos Aires. En función de ello, y teniendo como escenario posible lo que está ocurriendo en la actualidad, desde el Ministerio de Salud de la CABA, se comenzaron a diseñar estrategias de abordaje de carácter preventivo, para promover el control de este evento en la población en general y, en particular, en los niños susceptibles: por un lado, todos los menores de 6 años que cuentan -o deberían contar- con al menos una dosis de triple viral (entre el año de vida y el inicio escolar) y, principalmente, aquellos que por calendario, no les corresponde vacunación (los menores de un año). El 19 de julio de 2018, a poco menos de 3 meses del caso confirmado previo (categorizado como "relacionado con la importación", luego de haber hallado la fuente de infección proveniente de Asia), se notificaron dos casos confirmados que se atendieron en efectores públicos de la Ciudad de Buenos Aires, un residente de CABA y otro de Provincia de Buenos Aires. En este apartado se actualiza la situación epidemiológica a la fecha y se detallan las acciones realizadas y por realizar para la prevención y control de este evento.(AU)

Lessons learnt from a measles outbreak in Madang Province, Papua New Guinea, June 2014 - March 2015.

OBJECTIVE: This study examined measles vaccine wastage during an outbreak response in Madang Province of Papua New Guinea from June 2014 to March 2015. METHODS: Vaccine wastage was defined as the number of doses received by a health centre minus the total number of doses administered during and returned following the outbreak vaccination campaign. Vaccine data were collected from the Provincial Health Information Office, the Provincial Vaccine Store register and clinic and health centre immunization registers for calculating the vaccine wastage. Interviews were conducted with all 48 health centres involved in the outbreak response using a structured questionnaire to explore the reasons for vaccine wastage. RESULTS: Of the 154 110 doses issued by Madang Province during the outbreak, a total of 85 236 (55%) doses were wasted. The wastage varied by district from 31% to 90%. The total cost of the vaccine wastage was estimated to be 589 810 Kina (US$ 196 604). None of the health centres maintained vaccine stock registers. Most health centres indicated multiple failures in cold chain logistics. Almost 40% of health centres reported incorrectly diluting vaccines. The same percentage of health centres reported using incorrect injection techniques. DISCUSSION: Regular audits of cold chain logistics, staff training and improved processes for recording vaccine administration and wastage will decrease vaccine wastage during vaccine-preventable disease outbreaks and also benefit routine immunization activities.

An evaluation of the cold chain technology in South-East, Nigeria using Immunogenicity study on the measles vaccines.

INTRODUCTION: Vaccines are biological products and their efficacy is affected by storage conditions. They are vital in promoting public health. Failures in immunization programmes often times are blamed on disruption in vaccine cold-chain. This study assessed the immunogenicity/potency of the measles vaccines utilized in childhood immunization in South-East, Nigeria and indirectly assessed the effectiveness of the cold-chain technology in the region. METHODS: This was an experimental study carried out between December 2011 and June 2013. Antibody induction method was used to evaluate the immunogenicity/potency of the measles vaccines sourced from the central cold chain facilities in South-east, Nigeria and indirectly, the effectiveness of the cold chain technology in the zone in maintaining vaccine potency. The neutralizing antibodies in a control group (administered with measles vaccines stored at 37°C for 12 months) and in immunized group were determined after 30 days of immunization using ELISA. RESULTS: The mean storage temperature of the vaccines at the states vaccines central cold chain facilities was -2.4°C and before storage at study site, it was 5.8°C but at the study site it was -4.54°C. Mean ±Standard Error in the Mean (SEM) IgG titers for the measles vaccines sourced from "Open Market", Ebonyi, Enugu, Imo, Anambra and Abia States were 0.793±0.051, 1.621±0.015, 1.621±0.015, 1.715±0.081, 1.793±0.051 and 1.683±0.078 respectively while the mean ±Standard Error in the Mean (SEM) IgM titres were 0.857±0.037, 1.400±0.030, 1.391±0.032, 1.339±0.037, 1.405±0.066 and 1.279±0.025 respectively. One way analysis of variance shows that there is statistical difference in the IgG and IgM antibodies titers produced by the control compared to the vaccines (P value < 0.0001). Also, Bartlett's test for equal variances showed that there was statistical difference (P value < 0.0001 for IgG and = 0.036 for IgM). The antibodies elicited by the vaccines from the states were enough to confer protection but the vaccine samples from "Open Market" (control) could not evoke enough antibodies. CONCLUSION: The cold-chain technology in the region was judged to be optimal as at the time of vaccine sampling since all the measles vaccines had good immunogenicity profile. However, efforts are still needed to maintain these facilities in good condition in order to ensure effective immunization program in the region.

Framework for Optimal Global Vaccine Stockpile Design for Vaccine-Preventable Diseases: Application to Measles and Cholera Vaccines as Contrasting Examples.

Managing the dynamics of vaccine supply and demand represents a significant challenge with very high stakes. Insufficient vaccine supplies can necessitate rationing, lead to preventable adverse health outcomes, delay the achievements of elimination or eradication goals, and/or pose reputation risks for public health authorities and/or manufacturers. This article explores the dynamics of global vaccine supply and demand to consider the opportunities to develop and maintain optimal global vaccine stockpiles for universal vaccines, characterized by large global demand (for which we use measles vaccines as an example), and nonuniversal (including new and niche) vaccines (for which we use oral cholera vaccine as an example). We contrast our approach with other vaccine stockpile optimization frameworks previously developed for the United States pediatric vaccine stockpile to address disruptions in supply and global emergency response vaccine stockpiles to provide on-demand vaccines for use in outbreaks. For measles vaccine, we explore the complexity that arises due to different formulations and presentations of vaccines, consideration of rubella, and the context of regional elimination goals. We conclude that global health policy leaders and stakeholders should procure and maintain appropriate global vaccine rotating stocks for measles and rubella vaccine now to support current regional elimination goals, and should probably also do so for other vaccines to help prevent and control endemic or epidemic diseases. This work suggests the need to better model global vaccine supplies to improve efficiency in the vaccine supply chain, ensure adequate supplies to support elimination and eradication initiatives, and support progress toward the goals of the Global Vaccine Action Plan.

Comparative Estimates of Crude and Effective Coverage of Measles Immunization in Low-Resource Settings: Findings from Salud Mesoamérica 2015.

Timely and accurate measurement of population protection against measles is critical for decision-making and prevention of outbreaks. However, little is known about how survey-based estimates of immunization (crude coverage) compare to the seroprevalence of antibodies (effective coverage), particularly in low-resource settings. In poor areas of Mexico and Nicaragua, we used household surveys to gather information on measles immunization from child health cards and caregiver recall. We also collected dried blood spots (DBS) from children aged 12 to 23 months to compare crude and effective coverage of measles immunization. We used survey-weighted logistic regression to identify individual, maternal, household, community, and health facility characteristics that predict gaps between crude coverage and effective coverage. We found that crude coverage was significantly higher than effective coverage (83% versus 68% in Mexico; 85% versus 50% in Nicaragua). A large proportion of children (19% in Mexico; 43% in Nicaragua) had health card documentation of measles immunization but lacked antibodies. These discrepancies varied from 0% to 100% across municipalities in each country. In multivariate analyses, card-positive children in Mexico were more likely to lack antibodies if they resided in urban areas or the jurisdiction of De Los Llanos. In contrast, card-positive children in Nicaragua were more likely to lack antibodies if they resided in rural areas or the North Atlantic region, had low weight-for-age, or attended health facilities with a greater number of refrigerators. Findings highlight that reliance on child health cards to measure population protection against measles is unwise. We call for the evaluation of immunization programs using serological methods, especially in poor areas where the cold chain is likely to be compromised. Identification of within-country variation in effective coverage of measles immunization will allow researchers and public health professionals to address challenges in current immunization programs.

Role of vaccine manufacturers in developing countries towards global healthcare by providing quality vaccines at affordable prices.

Vaccines represent one of the greatest achievements of science and medicine in the fight against infectious diseases. Vaccination is one of the most cost-effective public health tools to prevent infectious diseases. Significant progress has been made in expanding the coverage of vaccines globally, resulting in the prevention of more than two million deaths annually. In 2010, nearly 200 countries endorsed a shared vision to extend the benefits of vaccines to every person by 2020, known as the Decade of Vaccine Initiative (DoV). Vaccine manufacturers in developing countries, as represented by the Developing Countries Vaccine Manufacturers Network (DCVMN), make a significant contribution to DoV by supplying quality vaccines at affordable prices to the people who need them most. About 70% of the global Expanded Program on Immunization (EPI) vaccine supplies are met by DCVMN. Besides EPI vaccine supplies, DCVMN is also targeting vaccines against rotavirus, Japanese encephalitis, pneumonia, human papillomavirus, meningitis and neglected tropical diseases. This article reviews the roles and contributions of DCVMN in making the vaccines accessible and affordable to all.

Immunisation coverage and its associations in rural Tanzanian infants.

INTRODUCTION: In Tanzania, vaccination rates (VRs) range from 80% to 90% for standard vaccines, but little information is available about rural populations and nomadic pastoralists. This study investigates levels and trends of the immunisation status of infants at eight mobile reproductive-and-child-health (RCH) clinics in a rural area in northern Tanzania (with a large multi-tribal population that has a significant population of nomadic pastoralists) for the years 1998, 1999, 2006 and 2007. In addition, the influence of tribal affiliation and health system-related factors on the immunisation status in this population is analysed. METHODS: Vaccination data of 3868 infants for the standard bacillus Calmette-Guérin (BCG), poliomyelitis, diphtheria, pertussis, tetanus and measles vaccines were obtained from the RCH clinic records retrospectively, and coverage for both single vaccines and full vaccination by the end of first year of life were calculated. These results were correlated with data on predominant tribal affiliation at the clinic site, skilled attendance at birth, service provision and vaccine availability as independent variables. RESULTS: In 1998, the full vaccination rate (FVR) across all RCH clinics was 72%, significantly higher than in the other years (1999: 58%; 2006: 58%; 2007: 57%) (p<0.0001). BCG and measles VRs were highest in 1998 and 1999, whereas VR was lowest for poliomyelitis in 1999, and for diphtheria-pertussis-tetanus in 2007 (all p<0.001). Measles VR showed a declining trend (1998: 72%; 1999: 73%; 2006: 62%; 2007: 59%) affecting the FVR, except in 1999 when poliomyelitis VR was lower (67%). FVR > 80% was only achieved at one clinic during 3 years. No clinic showed a consistent increase of VRs over time. In univariate analysis, predominant tribal affiliation (Datoga tribe) was associated with a low FVR (odds ratio (OR) 4.6 (95% confidence interval (CI) 3.8-5.5)), as were low rates of skilled attendance at birth (OR 3.6 (CI 2.9-4.4)). Other health system-related factors associated with low FVRs included interruption of scheduled monthly immunisation clinics (OR 9.8 (CI 2.1-45.5)) and lack of vaccines (OR 1.2-2.9, depending on vaccine). In multivariate analysis, predominant Datoga tribal affiliation and lack of vaccines retained their association with the risk of low rates of vaccination. CONCLUSIONS: Vaccination rates in this difficult-to-reach population are markedly lower than the national average for almost all years and clinics. Affiliation to the nomadic Datoga tribe and lack of vaccines determine VRs in this rural population. Improvements in immunisation service delivery, vaccine availability, stronger involvement of the nomadic communities and special outreach services for this population are required to improve VRs in these remote areas of Tanzania.

Identifying high-risk areas for sporadic measles outbreaks: lessons from South Africa.

OBJECTIVE: To develop a model for identifying areas at high risk for sporadic measles outbreaks based on an analysis of factors associated with a national outbreak in South Africa between 2009 and 2011. METHODS: Data on cases occurring before and during the national outbreak were obtained from the South African measles surveillance programme, and data on measles immunization and population size, from the District Health Information System. A Bayesian hierarchical Poisson model was used to investigate the association between the risk of measles in infants in a district and first-dose vaccination coverage, population density, background prevalence of human immunodeficiency virus (HIV) infection and expected failure of seroconversion. Model projections were used to identify emerging high-risk areas in 2012. FINDINGS: A clear spatial pattern of high-risk areas was noted, with many interconnected (i.e. neighbouring) areas. An increased risk of measles outbreak was significantly associated with both the preceding build-up of a susceptible population and population density. The risk was also elevated when more than 20% of infants in a populous area had missed a first vaccine dose. The model was able to identify areas at high risk of experiencing a measles outbreak in 2012 and where additional preventive measures could be undertaken. CONCLUSION: The South African measles outbreak was associated with the build-up of a susceptible population (owing to poor vaccine coverage), high prevalence of HIV infection and high population density. The predictive model developed could be applied to other settings susceptible to sporadic outbreaks of measles and other vaccine-preventable diseases.

Determining the optimal vaccine vial size in developing countries: a Monte Carlo simulation approach.

Outreach immunization services, in which health workers immunize children in their own communities, are indispensable to improve vaccine coverage in rural areas of developing countries. One of the challenges faced by these services is how to reduce high levels of vaccine wastage. In particular, the open vial wastage (OVW) that result from the vaccine doses remaining in a vial after a time for safe use -since opening the vial- has elapsed. This wastage is highly dependent on the choice of vial size and the expected number of participants for which the outreach session is planned (i.e., session size). The use single-dose vials results in zero OVW, but it increases the vaccine purchase, transportation, and holding costs per dose as compared to those resulting from using larger vial sizes. The OVW also decreases when more people are immunized in a session. However, controlling the actual number of people that show to an outreach session in rural areas of developing countries highly depends on factors that are out of control of the immunization planners. This paper integrates a binary integer-programming model to a Monte Carlo simulation method to determine the choice of vial size and the optimal reordering point level to implement an (nQ, r, T) lot-sizing policy that provides the best tradeoff between procurement costs and wastage.

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.

Impact of changing the measles vaccine vial size on Niger's vaccine supply chain: a computational model.

BACKGROUND: Many countries, such as Niger, are considering changing their vaccine vial size presentation and may want to evaluate the subsequent impact on their supply chains, the series of steps required to get vaccines from their manufacturers to patients. The measles vaccine is particularly important in Niger, a country prone to measles outbreaks. METHODS: We developed a detailed discrete event simulation model of the vaccine supply chain representing every vaccine, storage location, refrigerator, freezer, and transport device (e.g., cold trucks, 4 × 4 trucks, and vaccine carriers) in the Niger Expanded Programme on Immunization (EPI). Experiments simulated the impact of replacing the 10-dose measles vial size with 5-dose, 2-dose and 1-dose vial sizes. RESULTS: Switching from the 10-dose to the 5-dose, 2-dose and 1-dose vial sizes decreased the average availability of EPI vaccines for arriving patients from 83% to 82%, 81% and 78%, respectively for a 100% target population size. The switches also changed transport vehicle's utilization from a mean of 58% (range: 4-164%) to means of 59% (range: 4-164%), 62% (range: 4-175%), and 67% (range: 5-192%), respectively, between the regional and district stores, and from a mean of 160% (range: 83-300%) to means of 161% (range: 82-322%), 175% (range: 78-344%), and 198% (range: 88-402%), respectively, between the district to integrated health centres (IHC). The switch also changed district level storage utilization from a mean of 65% to means of 64%, 66% and 68% (range for all scenarios: 3-100%). Finally, accounting for vaccine administration, wastage, and disposal, replacing the 10-dose vial with the 5 or 1-dose vials would increase the cost per immunized patient from $0.47US to $0.71US and $1.26US, respectively. CONCLUSIONS: The switch from the 10-dose measles vaccines to smaller vial sizes could overwhelm the capacities of many storage facilities and transport vehicles as well as increase the cost per vaccinated child.