[Show abstract][Hide abstract] ABSTRACT: Objective & methodology:
The current study evaluated the effectiveness and cost-effectiveness of Insecticide Treated Curtain (ITC) deployment for reducing dengue vector infestation levels in the Cuban context with intensive routine control activities. A cluster randomized controlled trial took place in Guantanamo city, east Cuba. Twelve neighborhoods (about 500 households each) were selected among the ones with the highest Aedes infestation levels in the previous two years, and were randomly allocated to the intervention and control arms. Long lasting ITC (PermaNet) were distributed in the intervention clusters in March 2009. Routine control activities were continued in the whole study area. In both study arms, we monitored monthly pre- and post-intervention House Index (HI, number of houses with at least 1 container with Aedes immature stages/100 houses inspected), during 12 and 18 months respectively. We evaluated the effect of ITC deployment on HI by fitting a generalized linear regression model with a negative binomial link function to these data.
At distribution, the ITC coverage (% of households using ≥1 ITC) reached 98.4%, with a median of 3 ITC distributed/household. After 18 months, the coverage remained 97.4%. The local Aedes species was susceptible to deltamethrin (mosquito mortality rate of 99.7%) and the residual deltamethrin activity in the ITC was within acceptable levels (mosquito mortality rate of 73.1%) after one year of curtain use. Over the 18 month observation period after ITC distribution, the adjusted HI rate ratio, intervention versus control clusters, was 1.15 (95% CI 0.57 to 2.34). The annualized cost per household of ITC implementation was 3.8 USD, against 16.8 USD for all routine ACP activities.
Deployment of ITC in a setting with already intensive routine Aedes control actions does not lead to reductions in Aedes infestation levels.
PLoS ONE 03/2015; 10(3):e0119373. DOI:10.1371/journal.pone.0119373 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Introduction: Maintaining communities abreast of their local dengue situation could help to keep them motivated to participate in dengue control and to decrease Aedes entomological indexes. Objectives: To evaluate the coverage and reach of an intervention based on mass-media communication of dengue surveillance reports and its effect on the presence of intra-domiciliary breeding sites for Aedes in Guadalajara de Buga, Colombia. Materials and methods: An observational cross-sectional study was conducted in 1,426 households to identify the intra-domiciliary breeding sites and to characterize the intervention exposure. To evaluate the effect of the intervention, a case-control study was performed. All households with positive breeding sites were considered as cases. Four controls per case were randomly selected among the non-positive breeding site households located on the same block of the case. Results: The positive house index was 2.5%; coverage was 59.4% and reach was 22.3%. There was no association between the intervention and the presence of intra-domiciliary breeding sites. The presence of water plants and flower pots were associated to positive breeding sites (p=0.01) and the use of screens was associated to the absence of breeding sites (p=0.02). Conclusions: Although intervention coverage was adequate, the lack of association between the intervention and the absence of positive breeding sites requires assessing its fidelity, factors related to the design, and the implementation process.
Biomédica: revista del Instituto Nacional de Salud 09/2013; 33 Suppl 1:130-41. DOI:10.7705/biomedica.v33i0.724 · 0.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Effective participatory strategies in dengue control have been developed and assessed as small-scale efforts. The challenge is to scale-up and institutionalize these strategies within dengue control programs. We describe and critically analyze the diffusion process of an effective empowerment strategy within the Cuban Aedes aegypti control program, focusing on decision-making at the national level, to identify ways forward to institutionalize such strategies in Cuba and elsewhere. From 2005 to 2009, we carried out a process-oriented case study. We used participant observation, in-depth interviews with key informants involved in the diffusion process and document analysis. In a first phase, the data analysis was inductive. In a second phase, to enhance robustness of the analysis, emerging categories were contrasted with Rogers' five-stage conceptual model of the innovation-decision process, which was eventually used as the analytical framework. The diffusion of the empowerment strategy was a continuous and dynamic process. Adoption was a result of the perceived potential match between the innovative empowerment strategy and the performance gap of the Ae. aegypti control program. During implementation, the strategy was partially modified by top level Ae. aegypti control program decision-makers to accommodate program characteristics. However, structure, practices and organizational culture of the control program did not change significantly. Thus rejection occurred. It was mainly due to insufficient dissemination of know-how and underlying principles of the strategy by innovation developers, but also to resistance to change. The innovation-diffusion process has produced mitigated results to date, and the control program is still struggling to find ways to move forward. Improving the innovation strategy by providing the necessary knowledge about the innovation and addressing control program organizational changes is crucial for successful diffusion of empowerment strategies. Issues highlighted in this particular experience might be relevant in the innovation-diffusion process of other complex innovations within health systems.
Social Science [?] Medicine 05/2013; 84:44-52. DOI:10.1016/j.socscimed.2013.02.003 · 2.89 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Obtain baseline information on the status of the basic capacities of the health sector at the local, municipal, and provincial levels in order to facilitate identification of priorities and guide public policies that aim to comply with the requirements and capacities established in Annex 1A of the International Health Regulations 2005 (IHR-2005).
A descriptive cross-sectional study was conducted by application of an instrument of evaluation of basic capacities referring to legal and institutional autonomy, the surveillance and research process, and the response to health emergencies in 36 entities involved in international sanitary control at the local, municipal, and provincial levels in the provinces of Havana, Cienfuegos, and Santiago de Cuba.
The polyclinics and provincial centers of health and epidemiology in the three provinces had more than 75% of the basic capacities required. Twelve out of 36 units had implemented 50% of the legal and institutional framework. There was variable availability of routine surveillance and research, whereas the entities in Havana had more than 40% of the basic capacities in the area of events response.
The provinces evaluated have integrated the basic capacities that will allow implementation of IHR-2005 within the period established by the World Health Organization. It is necessary to develop and establish effective action plans to consolidate surveillance as an essential activity of national and international security in terms of public health.
Revista Panamericana de Salud Pública 09/2012; 32(3):207-16. DOI:10.1590/S1020-49892012000900006 · 0.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective To assess the economic cost of routine Aedes aegypti control in an at-risk environment without dengue endemicity and the incremental costs incurred during a sporadic outbreak. Methods The study was conducted in 2006 in the city of Guantanamo, Cuba. We took a societal perspective to calculate costs in months without dengue transmission (January-July) and during an outbreak (August-December). Data sources were bookkeeping records, direct observations and interviews. Results The total economic cost per inhabitant (p.i.) per month. (p.m.) increased from 2.76 USD in months without dengue transmission to 6.05 USD during an outbreak. In months without transmission, the routine Aedes control programme cost 1.67 USD p.i. p.m. Incremental costs during the outbreak were mainly incurred by the population and the primary/secondary level of the healthcare system, hardly by the vector control programme (1.64, 1.44 and 0.21 UDS increment p.i. p.m., respectively). The total cost for managing a hospitalized suspected dengue case was 296.60 USD (62.0% direct medical, 9.0% direct non-medical and 29.0% indirect costs). In both periods, the main cost drivers for the Aedes control programme, the healthcare system and the community were the value of personnel and volunteer time or productivity losses. Conclusions Intensive efforts to keep A. aegypti infestation low entail important economic costs for society. When a dengue outbreak does occur eventually, costs increase sharply. In-depth studies should assess which mix of activities and actors could maximize the effectiveness and cost-effectiveness of routine Aedes control and dengue prevention.
Tropical Medicine & International Health 09/2011; 17(1):123-32. DOI:10.1111/j.1365-3156.2011.02881.x · 2.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: During the dengue outbreak that struck Santiago de Cuba in 2006–2007, we conducted an observational study in the Mariana Grajales district, the former setting of a community trial for Aedes aegypti control. In the trial, community working groups (CWG) had been created in 29 randomly selected intervention house blocks, and routine vector control activities alone were conducted in the remaining 30 control blocks. The CWG elaborated and implemented with the population plans and activities to reduce Aedes infestation. They were still functional in 2006 and continued organizing community-based environmental management activities. The attack rate of dengue fever during the outbreak was 8.5 per 1000 inhabitants in the former intervention blocks and 38.1 per 1000 inhabitants in the control blocks, which corresponds to a relative risk of 4.5 (95% CI 3.1–6.5). There was a significantly higher proportion of unaffected intervention blocks, and affected blocks had on average substantially less cases than affected control blocks. This study indicates that community-based environmental management inserted in the routine A. aegypti control programme can not only sustainably curb vector infestation but also have an impact on dengue transmission.
Au cours de l’épidémie de dengue qui a affecté Santiago de Cuba en 2006-2007, nous avons mené une étude d’observation dans le district de Mariana Grajales, ancien cadre d’une étude sur le contrôle d’Aedes aegypti, basé sur la communauté. Dans l’étude, des groupes de travail communautaires (GTC) ont été créés dans 29 blocs de maisons d’intervention choisies de façon aléatoire et les activités de lutte antivectorielle de routine ont été menées dans 30 autres blocs témoins. Les GTC ont élaboré et mis en œuvre avec la population, des plans et des activités visant à réduire l’infestation par le genre Aedes. Ces GTC étaient encore fonctionnels en 2006 et ont continuéà organiser des activités communautaires sur la gestion environnementale. Le taux d’attaques de fièvre dengue au cours de l’épidémie était de 8,5 pour 1000 habitants dans les anciens blocs sous intervention et de 38,1 pour 1000 habitants dans les blocs témoins, ce qui correspond à un risque relatif de 4,5 (IC95%: 3,1-6,5). Il y avait une proportion significativement plus élevée de blocs sous intervention non affectés et les blocs affectés avaient en moyenne beaucoup moins de cas que les blocs témoins. La présente étude indique que la gestion environnementale communautaire, insérée dans le programme de routine de contrôle d’Aedes aegypti peut non seulement réduire durablement l’infestation par le vecteur, mais aussi avoir un impact sur la transmission de la dengue.
Durante el brote de dengue que azotó a Santiago de Cuba entre 2006-2007, realizamos un estudio observacional en el distrito de Mariana Grajales, en donde anteriormente se había realizado un ensayo comunitario para el control de Aedes aegypti. Durante el ensayo se crearon grupos de trabajo comunitarios (GTC) en 29 bloques de hogares elegidos al azar y que participaban en la intervención, mientras que en los 30 bloques restantes se llevaron a cabo solamente actividades de control vectorial rutinarias (grupo control). Los GTC elaboraron e implementaron los planes para la población y las actividades para reducir la infestación de Aedes. Los GTC continuaban siendo funcionales en el 2006 y organizando actividades de manejo ambiental basadas en la comunidad. La tasa de ataque de la fiebre del dengue durante el brote fue de 8.5 por 1000 habitantes en los bloques anteriormente intervenidos y de 38.1 por 1000 habitantes en los bloques control, lo que corresponde a un riesgo relativo de 4.5 (95% IC 3.1-6.5). Había una proporción significativamente mayor de bloques con intervención no afectados, y los bloques afectados tenían en promedio un número sustancialmente menor de casos que los bloques control afectados. Este estudio indica que un manejo ambiental, basado en la comunidad, dentro del programa rutinario de control de Aedes aegypti, no solo puede reducir sustancialmente la curva de infestación vectorial sino que puede tener un impacto sobre la transmisión del dengue.
Tropical Medicine & International Health 03/2011; 16(6):744-7. DOI:10.1111/j.1365-3156.2011.02762.x · 2.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Introducción. Los condilomas son causados por Papilomavirus Humano (PVH), esencialmente tipos 6 y 11. No se conoce la prevalencia de PVH en hombres cubanos seropositivos al Virus de la Inmunodeficiencia Humana (VIH). Objetivo. Detectar infección por PVH, genotipos y aspectos clínicos en hombres cubanos seroposi-tivos al VIH-1. Materiales y Métodos. Se estudiaron muestras de condilomas en 30 pacientes cubanos atendidos en el Instituto "Pedro Kourí". Al tejido se le realizó análisis histopatológico y detección de PVH me-diante Reacción en Cadena de la Polimerasa (RCP) con oligos MY09/11. Además, genotipificación con 32 sondas biotinadas, para PVH de alto o bajo riesgo oncogénico. Resultados. El ADN de PVH fue detectado en 100% de las muestras. Los genotipos 6 y 11 se identificaron en 63.3% y en 53.3% de los casos, respectivamente. En 19 individuos, se demostró coinfección con genotipos de bajo y alto riesgo. En un mismo paciente se pudieron detectar hasta 11 genotipos, con predominio de PVH 16 (50%) y 18 (43.3%). La terapia más usada fue el ácido tricloracético. Se observó asociación estadística [X 2 =11.27; RR=28.5; 95% IC: 2.6-306.6 (p=0.008)] entre la presencia de genotipos de alto riesgo oncogénico y el conteo de linfocitos T CD4+ < 500 células /mm 3 . Conclusiones. La detección de PVH de alto y bajo riesgo oncogénico, en lesiones condilomatosas de pacientes cubanos seropositivos al VIH-1, en relación con el conteo de CD4+ es un hallazgo de interés para el seguimiento y la detección temprana de neoplasias anogenitales.
[Show abstract][Hide abstract] ABSTRACT: Fidelity research can help to answer essential questions about the diffusion process of innovative health interventions and provide insights for further scaling-up and institutionalization. This study assessed fidelity and reinvention in the implementation of a community-based control strategy for Aedes aegypti control. The intervention was implemented in 16 study areas in La Lisa, a municipality of Havana, Cuba. Its major components were: organization & management, capacity-building, community work and surveillance. A participatory assessment of process data was performed to determine whether the components and subcomponents were implemented, not-implemented or modified. Frequencies were tabulated over all circumscriptions (lowest level of local government) and the average was calculated for the four components. Spearman Rank correlation coefficients were calculated to explore the relationships between components. In addition, semi-structured interviews were conducted with co-ordinators of the strategy at different levels to identify difficulties encountered in the strategy's implementation. Surveillance was the most implemented component (72.9%) followed by capacity-building (54.7%). Community work and organization & management were less implemented or modified (50% and 45%, respectively). Apart from surveillance and capacity-building, all components are significantly and strongly correlated (Spearman Rank correlation coefficient > 0.70, P < 0.01). If one component is implemented in a circumscription, the other components are also likely to be implemented. It is noticeable that areas which did not undergo organizational changes commonly did not implement community work activities. Within the whole strategy, few activities were added. Scarcely implemented subcomponents were the most innovative. The difficulties encountered during implementation were related to appropriate training and skills, available time, lack of support and commitment to the strategy, lack of motivation of local leadership, and integration of actors and resources. The study showed a wide variability of fidelity in the implementation of the intervention and highlighted challenges for scaling-up and institutionalization of the community-based intervention.
Health Policy and Planning 12/2010; 26(5):413-22. DOI:10.1093/heapol/czq077 · 3.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We compared in a 5-year intervention study the cost-effectiveness of community-based environmental management intertwined with routine vertical Aedes control and of routine vertical control only. At baseline (year 2000), Aedes infestation levels and economic costs for vector control were comparable in intervention and control areas (house index, 2.23% versus 2.21% and US$21 versus US$24/yr/inhabitant, respectively). By 2004, house indices became 0.22% versus 2.36% and the costs were 29.8 US$ versus 36.7 US$/yr/inhabitant, respectively. The community cost made up 38.6% of the total economic cost in 2004 in the intervention areas against 23.5% in 2000. The average cost-effectiveness ratio for the intervention period 2001-2004, expressed as the societal cost incurred for the reduction (from baseline) of Aedes foci, was US$831.1 per focus in the intervention areas versus US$2,465.6 in the control areas. The intervention produced economic savings and health benefits that were sustained over the whole observation period.
The American journal of tropical medicine and hygiene 08/2009; 81(1):88-93. · 2.70 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To assess the effectiveness of an integrated community based environmental management strategy to control Aedes aegypti, the vector of dengue, compared with a routine strategy.
Cluster randomised trial.
32 circumscriptions (around 2000 inhabitants each).
The circumscriptions were randomly allocated to control clusters (n=16) comprising routine Aedes control programme (entomological surveillance, source reduction, selective adulticiding, and health education) and to intervention clusters (n=16) comprising the routine Aedes control programme combined with a community based environmental management approach.
The primary outcome was levels of Aedes infestation: house index (number of houses positive for at least one container with immature stages of Ae aegypti per 100 inspected houses), Breteau index (number of containers positive for immature stages of Ae aegypti per 100 inspected houses), and the pupae per inhabitant statistic (number of Ae aegypti pupae per inhabitant).
All clusters were subjected to the intended intervention; all completed the study protocol up to February 2006 and all were included in the analysis. At baseline the Aedes infestation levels were comparable between intervention and control clusters: house index 0.25% v 0.20%, pupae per inhabitant 0.44x10(-3) v 0.29x10(-3). At the end of the intervention these indices were significantly lower in the intervention clusters: rate ratio for house indices 0.49 (95% confidence interval 0.27 to 0.88) and rate ratio for pupae per inhabitant 0.27 (0.09 to 0.76).
A community based environmental management embedded in a routine control programme was effective at reducing levels of Aedes infestation.
Current Controlled Trials ISRCTN88405796.
[Show abstract][Hide abstract] ABSTRACT: To identify key elements that should provide an added value and assure sustainable effects of the deployment of technical tools for Aedes aegypti control.
An observational study was conducted between April 2001 and March 2002 in 30 blocks (1574 houses) in the central zone of Guantanamo city. A trial that combined two complementary technical interventions, the distribution of new ground level water tanks and the intensive use of insecticide, was nested in May 2001. Another 30 blocks (1535 houses) were selected as control area. We assessed community perceptions and household risk behaviour at baseline and after 9 months, and measured the trial's impact through entomological indices.
Perceived self efficacy to solve A. aegypti infestation and prevent dengue was not modified. We found no changes in behaviour. In the study area the container indices decreased significantly from 0.7% before to 0.1% 1 month after the intervention. Six months later, they had increased to 2.7% and uncovered new water tanks constituted 75.9% of all breeding sites. Over the 9 months after the trial the average monthly house indices were similar in the study and control areas. A technical approach and lack of community involvement in the trial's implementation were the main causes of these short-lived results.
Top-down deployment of technical tools without active involvement of the community has a temporary effect and does not lead to the behavioural changes necessary for sustainable A. aegypti control.
Tropical Medicine & International Health 06/2008; 13(5):728-36. DOI:10.1111/j.1365-3156.2008.02046.x · 2.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We conducted an economic appraisal of two strategies for Aedes aegypti control: a vertical versus a community-based approach. Costs were calculated for the period 2000-2002 in three pilot areas of Santiago de Cuba where a community intervention was implemented and compared with three control areas with routine vertical programme activities. Reduction in A. aegypti foci was chosen as the measure of effectiveness. The pre-intervention number of foci (614 vs. 632) and economical costs for vector control (US$243746 vs. US$263486) were comparable in the intervention and control areas. During the intervention period (2001-2002), a 13% decrease in recurrent costs for the health system was observed. Within the control areas, these recurrent relative costs remained stable. The number of A. aegypti foci in the pilot areas and the control areas fell by 459 and 467, respectively. The community-based approach was more cost effective from a health system perspective (US$964 vs. US$1406 per focus) as well as from society perspective (US$1508 vs. US$1767 per focus).
Transactions of the Royal Society of Tropical Medicine and Hygiene 07/2007; 101(6):578-86. DOI:10.1016/j.trstmh.2007.01.002 · 1.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Community participation is advocated as essential for attaining effective dengue prevention, but knowledge of how to foster this is limited. In Santiago de Cuba, multiple small task forces were created at the neighbourhood level that included all stakeholders in the control of Aedes aegypti. The task forces assessed the perceived needs and elaborated action plans to promote specific behavioural change and to reduce environmental risks through social communication strategies and intersectoral local government activities. We monitored five dimensions of the participation process and assessed behavioural and environmental results and entomological outcomes. Participation was weak to good. At the household level, uncovered water storage containers decreased from 49.3% to 2.6% between 2000 and 2002, and removing larvicide from them dropped from 45.5% to 1%. There was a reduction of 75% in the absolute number of positive containers and a significant decrease from 1.23% to 0.35% in the house index. Local task forces, in which the interests of householders as well as vector control workers are directly represented, can lead to effective government-community partnerships that resolve problems of mutual concern.
Transactions of the Royal Society of Tropical Medicine and Hygiene 02/2007; 101(1):56-63. DOI:10.1016/j.trstmh.2006.03.006 · 1.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Since 1989, we have been involved in the development of a vaccine against Haemophilus influenzae type b. The new vaccine is based on the conjugation of synthetic oligosaccharides to tetanus toxoid. Our main goals have
been (i) to verify the feasibility of using the synthetic antigen and (ii) to search for new production alternatives for this
important infant vaccine. Overall, eight trials have already been conducted with adults, children (4 to 5 years old), and
infants. We have described herein the details from the first two phase I clinical trials conducted with human adult volunteers
under double blind, randomized conditions. The participants each received a single intramuscular injection to evaluate safety
and initial immunogenicity. We have found an excellent safety profile and an antibody response similar to the one observed
for the control vaccine.
[Show abstract][Hide abstract] ABSTRACT: HIV infection in children causes a serious immunodeficiency with special characteristics that distinguish it from the adult, causing a global immune deficit. This is a case-control study between Cuban paediatric patients infected with HIV by vertical transmission and a control group of supposedly healthy children. Both groups were characterized from the clinical point of view and markers were used for evaluating the immunologic and virologycal state. Clinically 75% of patients present a pattern of precocious progression; from the total, only two stayed asymptomatic. All HIV-infected children receive antirretroviral treatment and three of them present values of viral load bigger than 100,000 cp/mL. The immune alterations found in the HIV-infected children compared with healthy children were: a cellular immune depletion with diminished counts of lymphocyte subsets T CD4+, CD16+/CD56+ and CD19+, an increase in subsets of CD3+, CD8+, CD8+/CD38+, CD3+/ CD95+ and a hypergammaglobulinemia due to prevalence of immunoglobulin gamma IgG (p < 0.05). On the other hand, there were not significantly differences in the serum levels of both C3 and C4, as well as in the haemolytic activity of the classic and alternate activation pathways of the complement system. This finding allowed better attention and treatment of paediatric HIV patients.
Revista de investigacion clinica; organo del Hospital de Enfermedades de la Nutricion 01/2005; 57(4):498-504. · 0.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: HIV infection in children conditions a serious immunodeficiency with special characteristic that distinguish it from the adult, causing a global immune deficit. This constitutes a cases and controls study between Cuban paediatric patients infected with HIV by vertical transmission and a control group of supposedly healthy children. The both groups were characterized from the clinical point of view and markers were used for evaluated the immunologic and virologycal state. Clinically 75% of patients present a pattern of precocious progression, from total only two stay asymptomatic. All HIV infected children receive antirretroviral treatment and three of them present values of viral load bigger than 100,000 cp/mL. The immune alterations found in the HIV infected children compared with healthy children were: a cellular immune depletion with diminish counts of lymphocytes subsets of T CD4+, CD16+/CD56 + and CD19+, an increase in subsets of CD3+, CD8+, CD8+/CD38+, CD3+/ CD95+ and a hipergammaglobulinemia to prevalence of immunoglobulin gamma IgG (p < 0.05). On the other hand, they were not significantly differences in the serum levels of both C3 and C4, as well as in the haemolytic activity of the roads classic and it alternates of the complement system. This finding allowed us to a better attention and treatment of paediatric HIV patients.
Revista Electronica de Investigacion Educativa 01/2005; 57(4):498-504.
[Show abstract][Hide abstract] ABSTRACT: Polysaccharide-protein conjugates as vaccines have proven to be very effective in preventing Haemophilus influenzae type b infections in industrialized countries. However, cost-effective technologies need to be developed for increasing the
availability of anti-H. influenzae type b vaccines in countries from the developing world. Consequently, vaccine production with partially synthetic antigens
is a desirable goal for many reasons. They may be rigidly controlled for purity and effectiveness while at the same time being
cheap enough that they may be made universally available. We describe here the antigenicity and immunogenicity of several
H. influenzae type b synthetic oligosaccharide-protein conjugates in laboratory animals. The serum of H. influenzae type b-immunized animals recognized our synthetic H. influenzae type b antigens to the same extent as the native bacterial capsular polysaccharide. Compared to the anti-H. influenzae type b vaccine employed, these synthetic versions induced similar antibody response patterns in terms of titer, specificity,
and functional capacity. The further development of synthetic vaccines will meet urgent needs in the less prosperous parts
of the world and remains our major goal.
Infection and Immunity 01/2005; 72(12):7115-23. DOI:10.1128/IAI.72.12.7115-7123.2004 · 3.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Glycoconjugate vaccines provide effective prophylaxis against bacterial infections. To date, however, no commercial vaccine has been available in which the key carbohydrate antigens are produced synthetically. We describe the large-scale synthesis, pharmaceutical development, and clinical evaluation of a conjugate vaccine composed of a synthetic capsular polysaccharide antigen of Haemophilus influenzae type b (Hib). The vaccine was evaluated in clinical trials in Cuba and showed long-term protective antibody titers that compared favorably to licensed products prepared with the Hib polysaccharide extracted from bacteria. This demonstrates that access to synthetic complex carbohydrate-based vaccines is feasible and provides a basis for further development of similar approaches for other human pathogens.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the efficacy of vax-SPIRAL, a Cuban vaccine against leptospirosis, and to provide additional information concerning the safety of this vaccine (which was developed by Cuba's Finlay Institute).
This phase III efficacy trial of vax-SPIRAL was controlled, randomized, and double blind. The control vaccine used for the trial was Heberbiovac-HB (Heber Biotec, Cuba), a recombinant hepatitis B vaccine. The randomization unit for allocating persons to the study group or the control group were 523 family physician offices in the selected municipalities. The study covered the entire population of males and females from 20 to 64 years old who voluntarily agreed to participate, from the municipalities of Ranchuelo, Quemado, Santo Domingo, Encrucijada, Corralillo, Cifuentes, and Camajuaní, which are in the province of Villa Clara, in the central region of Cuba. The vaccinations were given in the physicians' offices between February and July 1998, with an interval of 6 weeks between the two doses. The follow-up period was 12 months. A case was considered positive if a person who had received the two doses of the vaccine became ill with leptospirosis more than 21 days after receiving the second dose, with the diagnosis confirmed through serological and microbiological methods. We calculated the efficacy of the vaccine and the relative risk of becoming ill with leptospirosis after the vaccination. For the safety study, two persons were chosen at random from among the individuals vaccinated at the office of each physician participating in the study. Follow-up of local and systemic adverse reactions was carried out by the family physicians during the seven days after the application of each dose. The level of statistical significance was set at 0.05.
A total of 101 832 persons were vaccinated, with 50 354 of them (49.4%) receiving the leptospirosis vaccine and 51 478 of them (50.6%) receiving the control vaccine. The efficacy of the vax-SPIRAL vaccine was 78.1% (95% confidence interval (CI): 59.2% to 88.3%), and the relative risk of becoming ill with leptospirosis after receiving the leptospirosis vaccine was 0.22 (95% CI: 0.12 to 0.41). General discomfort was the most frequent systemic adverse reaction, and mild spontaneous pain at the injection site was the most frequent local effect. The local and systemic adverse reactions were both more frequent in the study group than in the control group (P = 0.003). There were no serious adverse events.
The vax-SPIRAL vaccine proved to be safe and efficacious for leptospirosis control. The vaccine is recommended for use in preventing this disease among groups at risk of contracting it.
Revista Panamericana de Salud Pública 05/2004; 15(4):249-55. DOI:10.1590/S1020-49892004000400005 · 0.85 Impact Factor