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C de Quadros

Publications and source records attributed to C de Quadros.

11 recordsLinked to original sources
PubMed2001

Considerations for combination vaccine development and use in the developing world.

As more vaccines are developed and become available, combination vaccines will provide a way of delivering multiple antigens to avoid multiple injections and complications in the regular immunization schedules. The advantages of combination vaccines are that they decrease the discomfort of vaccine recipients and parents and also reduce the delivery cost of vaccines. We address some of the issues related to the use of combination vaccines in the developing world. Which vaccines are needed? Do developing countries have the appropriate infrastructure to deliver them? Can vaccines become affordable for countries with low incomes? And what is really needed to achieve the goal of providing developing countries with new vaccines of epidemiologic significance in a timely fashion?

Americas↗
PubMed1999

[Introduction of a conjugate vaccine against Hib in Chile and Uruguay].

In some countries, the invasive disease caused by Haemophilus influenzae type b (Hib) has been practically eliminated thanks to vaccination. However, in much of the developing world, meningitides and pneumonias caused by these bacteria continue to be a major cause of childhood morbidity and mortality, as well as high hospitalization costs. Because safe and effective conjugate vaccines are now available, the Special Program for Vaccines and Immunization of the Pan American Health Organization has recommended introducing them into the regular vaccination regimen of as many countries as possible. This has been done in Chile and Uruguay, where the Hib vaccine now forms part of the regular vaccination routine. When the vaccine was being introduced, both countries had difficulties they could have avoided if they had known of the experiences of other nations. Therefore, these two countries now offer the lessons they learned to other nations considering introducing the vaccine into their immunization programs. The most important lessons were to: strengthen the epidemiological surveillance system sufficiently in advance of introducing the vaccine; with the support of scientific societies, present the technical information that justifies introducing the vaccine; seek community backing and acceptance; precisely establish in advance the presentation and dosage of the vaccine that is most appropriate for the country; and be certain to have the political and legal decisions needed to ensure the continuity of Hib vaccination in the future.

Child↗
PubMed1998

Perspectives from the global poliomyelitis eradication initiative.

Ten years after the year 2000 target was set by the World Health Assembly, the global poliomyelitis eradication effort has made significant progress towards that goal. The success of the initiative is built on political commitment within the endemic countries. A partnership of international organizations and donor countries works to support the work of the countries. Interagency coordinating committees are used to ensure that all country needs are met and to avoid duplication of donor effort. Private sector support has greatly expanded the resources available at both the national and international level. At the programmatic level, rapid implementation of surveillance is the key to success, but the difficulty of building effective surveillance programmes is often underestimated. Mass immunization campaigns must be carefully planned with resources mobilized well in advance. Programme strategies should be simple, clear and concise. While improvements in strategy and technology should be continuously sought, changes should be introduced only after careful consideration. Careful consideration should be given in the planning phases of a disease control initiative on how the initiative can be used to support other health initiatives.

Global Health↗
PubMed1998

[Public laboratories for vaccine production: a new paradigm].

In Latin America and the Caribbean, public laboratories that produce vaccines have contributed in varying degrees to the control and eradication of vaccine-preventable diseases, and several of them are manufacturing vaccines that are routinely applied in national immunization programs, such as the vaccine against tuberculosis (made with the bacillus of Calmette-Guérin, BCG), the triple vaccine against diphtheriatetanus-pertussis (DTP), tetanus toxoid (TT), the vaccine against measles and the oral vaccine against polio. Thanks to recent scientific strides, one can foresee an important increase in the number of safe and effective vaccines that will be available in the near future for use in routine vaccination programs. However, there are high costs involved in developing such vaccines and in protecting the intellectual property rights involved, and few laboratories in Latin America have the technical capacity to research and develop these vaccines. Such factors will affect the speed with which they are assimilated into vaccination programs in countries of the Region. Currently, public laboratories that manufacture vaccines in the Region are not equipped to compete in this new scenario and run the risk of being completely outmarketed. Thus, they must radically change their style of management and their scientific and technical capabilities, backed by a commitment from governments to improve and strengthen those political and financial aspects that can assure that national laboratories participate in the sustainable supply of vaccines to immunization programs, as well as in researching, developing, and producing new vaccines.

Caribbean Region↗
PubMed1995

Epidemiology and clinical characteristics of acute flaccid paralysis associated with non-polio enterovirus isolation: the experience in the Americas.

The Pan American Health Organization adopted as a goal the interruption of transmission of wild poliovirus from the americas by 1990. Collection and processing of stool specimens from patients with acute flaccid paralysis (AFP) to identify wild poliovirus is critical for monitoring the success of the eradication programme. In the study described, cases of AFP in children less than 15 years of age reported in the Americas from 1989 to 1991 were evaluated to investigate the epidemiology of AFP associated with the isolation of non-polio enterovirus (NPEV), to characterize their clinical presentation, and to compare their clinical characteristics with those of AFP cases associated with the isolation of wild poliovirus (confirmed as poliomyelitis). The results show that the notification pattern for AFP associated with NPEV isolates is similar to that for all AFP cases. While AFP associated with NPEV isolates generally differs clinically from confirmed poliomyelitis, 2-21% of cases met one of three case definitions for poliomyelitis. Following the eradication of poliomyelitis, countries can therefore anticipate the continued reporting of cases of AFP that clinically mimic poliomyelitis but which are associated with NPEV. The study also confirms that NPEV circulation is common and that most isolates were from cases that did not resemble poliomyelitis. It is therefore questionable whether characterization of NPEV isolates is essential for global eradication of poliomyelitis and consequently whether allocation of resources for that purpose can be justified.

Acute Disease↗
PubMed1994

Paralytic poliomyelitis: seasoned strategies, disappearing disease.

With more than 2 years having elapsed since the last case of paralytic poliomyelitis occurred in the Western Hemisphere, significant progress has been made towards the global eradication of wild polioviruses. Poliomyelitis is disappearing from Europe, North Africa, Southern Africa, the Middle East, China, and the Pacific. Reported poliomyelitis cases declined to 15,587 cases in 1992. Current eradication strategies recommended by the World Health Organization include national mass campaigns administering oral poliovaccine to all children under 5 years of age, enhanced surveillance to detect cases of acute flaccid paralysis, creating a network of laboratories for viral diagnosis, and targeted immunisation to areas and populations where poliovirus transmission is likely to persist. The major obstacles to eradication include inadequate political support for eradication and insufficient funding, especially for the purchase of vaccine. With additional support for the international eradication effort, epidemics of poliomyelitis will cease in developing countries, and industrialised countries will be able to save the large sums spent each year on poliovaccine and rehabilitation.

Global Health↗
PubMed1992

Screening of cases of acute flaccid paralysis for poliomyelitis eradication: ways to improve specificity.

The Pan American Health Organization in 1985 adopted an initiative to eradicate poliomyelitis from the Western Hemisphere. In 1990, over 2000 cases of acute flaccid paralysis (AFP) were reported in this region, of which < 1% were determined to be caused by wild poliovirus. At present, the eradication programme uses AFP as the criterion for surveillance of children aged < 15 years; this is 100% sensitive, but not specific. To minimize unnecessary diagnostic investigations, we studied all 4333 cases of AFP reported to the programme during 1989 and 1990 in order to develop more efficient operational screening criteria for cases of AFP. Among children with AFP, the use of criteria such as age < 6 years and either presence of fever at the onset of paralysis or a < 4-day period for complete development of paralysis resulted in a sensitivity of 96% (95% C.I. 90-103%) and specificity of 49% (C.I. 47-52%). With criteria of age < 6 years and fever present at the onset of paralysis the sensitivity was 75% (C.I. 61-89%) and specificity was 73% (C.I. 71-75%). These results suggest that by screening young children with AFP who either had fever at the onset or showed a rapid progression of paralysis, the number of cases of AFP requiring investigation can be reduced by one half, with minimal compromise in the sensitivity of confirmed poliomyelitis case detection.

Adolescent↗
PubMed1992

Poliomyelitis case confirmation: characteristics for use by national eradication programmes.

Highly sensitive case definitions were first introduced by national poliomyelitis eradication programmes to avoid missing true cases of the disease, though false-positive diagnostic errors could still occur owing to low specificity. Extensive data from all 1620 cases of acute, flaccid paralysis reported in Brazil during 1987-88 provided an opportunity to study the characteristics of confirmed poliomyelitis cases and epidemiologically to evaluate potential case definitions that maximized both sensitivity and specificity. Cases that had been confirmed by wild poliomyelitis virus isolation were compared with those that had been rejected (non-polio cases). To guarantee the consistency of clinical, epidemiological and laboratory investigations, only cases less than 10 years of age that had been investigated within 15 days of the onset and with complete laboratory specimens were included. No single practical case definition combining both high sensitivity and high specificity emerged from the study. However, the results showed that poliomyelitis endemic countries with limited resources should give priority to the investigation of cases in less than 5-year-olds, cases with prodromal fever, cases without involvement in all four limbs, cases without progression greater than 3 days after the onset, and cases occurring in areas where poliomyelitis had recently been confirmed. In countries without laboratory resources, cases of acute, flaccid paralysis with initial involvement in one or both lower limbs and residual neurological sequelae at 60 days should be confirmed. Countries that are close to eradication may selectively reject any cases lacking laboratory confirmation, despite adequate specimen collection, if they do not have initial involvement in one or both lower limbs and residual neurological sequelae at 60 days.

Brazil↗
PubMedDate not supplied

Field evaluation of a simplified unit-dose syringe for administration of measles vaccine.

Ezeject is a plungerless syringe prefilled with lyophilized measles vaccine. Ezeject syringes were compared with standard 3-cc syringes and 10-dose measles vaccine vials in the vaccination of 884 Guatemalan infants 8-23 months of age. Vaccination was performed by experienced vaccinators and by individuals without prior vaccination experience who received 2.5-3 hours of training. The overall seroconversion rate following administration was 96%, regardless of the type of syringe used or of the experience of the vaccinator. No significant adverse events were observed in children vaccinated with the new syringes. Although incomplete emptying was noted in 87% of the Ezeject syringes used, this had no effect on the serologic response to measles vaccine. Aspiration for detection of blood before injection of the vaccine was performed significantly (P less than .001) less frequently with Ezeject than with 3-cc syringes by both experienced and inexperienced personnel. Inexperienced vaccinators administered measles vaccine significantly faster (P less than .001) with Ezeject than with 3-cc syringes, but the times were similar for experienced vaccinators. Ezeject is an acceptable alternative to standard syringes for the administration of measles vaccine. Several design modifications that would improve the handling of the device and eliminate the possibility of its reuse have been suggested.

Antibodies, Viral↗