Control Of Poliomyelitis Research Articles

The control of poliomyelitis in Brazil.

A program of mass vaccination with oral polio vaccine was launched in 1980 in Brazil. The aim was to reach in a single day, twice a year, the whole population of children younger than five years of age, irrespective of their vaccination history. More than 20 million children were vaccinated in each of the six campaigns carried out until 1982. Recorded rates of immunization exceeded 90% in the target age group. The incidence of poliomyelitis dropped from an average of 2,330 cases in the 1975-1980 period to only 122 cases in 1981. Provisional figures for 1982 indicate that the total number of confirmed cases will be close to 70. Similar campaigns are intended for 1983 and 1984, but the continuation of this strategy after 1984 is still under discussion.

Control of poliomyelitis in Africa.

In Africa, an estimated 168,000 children are disabled by poliomyelitis every year. With the use of lameness surveys to estimate incidence before immunization, surveys to measure vaccination coverage, and surveillance to monitor disease trends, poliomyelitis control in Yaound é, Cameroon; The Gambia; and Abidjan, Ivory Coast was examined. Three doses of oral poliovirus vaccine have been administered to 50%-70% of the children. The incidence of poliomyelitis has decreased significantly. Oral poliovirus vaccine administered during the first year of life has been effective in controlling poliomyelitis in tropical Africa.

Poliomyelitis control in Japan.

The Sabin oral poliovirus vaccine ( OPV ) has been used in Japan since 1961. Since then the number of paralytic cases has decreased markedly. The incidence of paralytic and positive rates for antibodies to poliovirus were analyzed. The number of paralytic cases associated with OPV was low for cases due to type 1 virus and high for those due to type 2 virus. As for cases due to type 3 virus, the number was high until 1969 and has been low since 1970. This difference was brought about by changing the batch of type 3 virus used in the preparation of OPV . The analysis of titers of neutralizing antibody showed that response to type 1 virus in OPV used in 1977 and to type 3 virus in OPV used in 1972 and 1973 was not adequate. Both situations were improved by changing the batches of virus used for OPV . These experiences suggest that the use of good batches is necessary for safety and efficacy of OPV .

Priorities in health care: a discussion.

I wish to make two points related to the notion that the more limited resources are, the more important careful choice among competing options becomes. The first point is that polio immunization alone is not self-evidently the top priority for increased resource allocation in most developing countries, but that its priority is enhanced when it is considered as a part of the package of services combatting infectious childhood diseases. The second point is that there are just three potential sources of increased economic support for immunization: foreign aid, domestic economic growth, or a shift in priorities for domestic expenditure. Dr. Robinson raised the question of priority for control of poliomyelitis in his presentation [1] and appropriately considered its political context, which of course is always present. The major function that health planners can exercise in this forum is to raise the level of debate by introducing evidence, reasons, and a wider spectrum of values into the decision-making process. There have been very few attempts to apply the kind of explicit criteria suggested in discussion by Dr. Foster for measuring the relative priority of alternative basic health actions. But there are two recent scaling exercises in which poliomyelitis was assessed together with a long list of other disease problems. The Ghana Health Assessment Project Team [2] ranked 48 disease problems in that country in terms of economic burden-measured as days of healthy life lost per 1,000 persons per year. Their calculations took account of estimated incidence, case fatality rate, age at death, and level and permanence of disability for each disease. Overall, poliomyelitis in Ghana ranked 33rd of the 48 diseases considered. Malaria and measles were at the top; and tuberculosis, neonatal and adult tetanus, typhoid, and pertussis were all in the top 25. The study was limited in not considering the effectiveness or the costs of available interventions, which would raise the relative position of poliomyelitis.

Political, administrative, and economic resources for the control of poliomyelitis.

Control of any major childhood disease in developing countries is dependent on the ability of health services to reach the susceptible population and to administer appropriate therapy or preventive action. Both of these needs are addressed by the development of primary health-care services. The vaccine-preventable diseases, including poliomyelitis, are likely to be controlled only through programs that are executed through the primary health-care system. The implications of the technical aspect of poliomyelitis control on economic resources are secondary to the administrative capability of the programs to manage these technical facilities effectively. The first prerequisite of any health program is the political will on the part of the decision makers to carry it through effectively. This will be reflected in the strength of the administrative structures and the economic resources made available. At present poliomyelitis, with its clinical visibility and its appeal to humanitarian instincts, has an importance as a leader for immunization programs and thus, for primary health care.

Can paralytic poliomyelitis be eliminated?

The question of whether paralytic poliomyelitis can be eliminated can be approached either from the theoretic and scientific perspective or from the practical perspective of a program. From the former perspective, the answer is probably yes; from the latter, the answer would be that global eradication of this disease cannot be achieved by the year 2000. The global eradication of smallpox was a remarkable achievement and is held up as an example to show that the deliberate worldwide elimination of a human infectious-disease agent can be scheduled and accomplished. However, there are significant differences in the epidemiology and in the control programs for smallpox and poliomyelitis that make the global eradication of poliomyelitis more difficult. Presently, scarce resources for improving health throughout the world cannot be easily diverted for the specific purpose of eradicating paralytic poliomyelitis. The control of poliomyelitis for the next decade will have to proceed at the same relative pace as other major disease control programs of the World Health Organization, such as the Expanded Programme on Immunization and the International Drinking Water Supply and Sanitation Decade. After 1990, the extent to which these programs have controlled or regionally eliminated paralytic poliomyelitis can be assessed. It may be more appropriate then to ask the question, can paralytic poliomyelitis be eliminated?

Poliomyelitis in India: prospects and problems of control.

Based on many surveys of residual paralysis and limited surveillance, the incidence of acute paralytic poliomyelitis in India has been calculated to be 20-40 per 100,000 population per year; thus greater than 200,000 cases occur annually, or 500 every day. Although oral polio vaccine ( OPV ) has been highly effective in controlling outbreaks, its introduction in routine immunization programs has not succeeded in controlling poliomyelitis in India. This failure is the result of inappropriate immunization strategy and low rates of antibody response to vaccine virus. Injectable polio vaccine, although found to be highly effective in routine immunization programs, is very costly and in short supply. The annual immunization of the susceptible age group with OPV during a short period (pulse immunization) has been found to be highly effective; this strategy is recommended for national control of poliomyelitis.

Prospects for worldwide control of paralytic poliomyelitis: a discussion.

In notes to speakers and other participants distributed prior to this symposium, it was stated that it is important that all presentations, comments and discussions be devoted to information. What new can last discussant on last day of such a remarkable three and one-half day meeting present that is relevant? In particular, how does that information relate to prospects for worldwide control, subject of this final session? The notes to speakers also stated that one purpose of symposium is the identification of research needs critical to worldwide control of poliomyelitis, suggesting, by inference, that products of this research would determine the feasibility of eradication of disease. As a representative of National Institutes of Health (NIH) and its National Institute of Allergy and Infectious Diseases (NIAID), major source of support for basic research in microbiology and infectious diseases, and as one who has listened to technologic and public-health achievements recounted by previous speakers, I propose to address joint questions of research and feasibility. As for new information, I report that NIAID currently (March 1983) supports only 10 research grants and four individual research training grants for studies on polioviruses, at a direct cost of $1,065,787. These investigators, three of whom discussed their research with you yesterday, are examining various aspects of molecular biology of polioviruses. Their goal is to learn more about viruses, not to develop a better vaccine, although it is clear that latter may result. This modest research effort may be contrasted with 31 research grants and one training grant funded in fiscal year 1982 by NIAID for research on genital herpes, at a cost of $3,777,000. Since

Practicalities of a global poliomyelitis control program.

Much progress has been achieved in making the world free of poliomyelitis. The countries that have achieved control should be giving practical help to those where the disease is still endemic, while developing their own competence in surveillance, laboratory support, and effective immunization policies. The polio vaccines have been proved effective. The need is now to implement programs by solving their practical difficulties in order to make use of the presently available vaccines.

Paralytic poliomyelitis can be eliminated.

Since the introduction and widespread use of inactivated and oral poliovirus vaccines, there has been a continued and increasing commitment to worldwide poliomyelitis control. The eradication of poliomyelitis in certain countries, smallpox eradication worldwide, the World Health Organization's (WHO) Expanded Programme on Immunization, and advances in poliovirus vaccine production augur well for worldwide elimination within the next few decades. The success of any such program rests firmly upon scientific feasibility, intensive epidemiologic surveillance, and economic justification. The development of a variety of disease-specific control/prevention programs worldwide have improved communicable disease reporting in many countries and established health-care infrastructure as well. Equally important has been the emergence of the concept of epidemiologic surveillance. The success of poliomyelitis elimination in large parts of the world, the WHO commitment, and the tragic, visible effects of poliomyelitis are sufficiently strong arguments to persuade the countries of the world to make the necessary effort to eliminate poliomyelitis within the next generation.

Mass vaccination against poliomyelitis in Mexico.

In 1959, oral poliovirus vaccine ( OPV ) was introduced as an antiepidemic measure in Mexico. As in many other developing countries, the vaccine was misused, coverages achieved were often poor, and an adequate cold chain was lacking. However, in 1972 a mass campaign reached 70% of children younger than five years of age, and consequently the reported cases declined sharply from 1.9 to 0.4 per 100,000 population. Due to economic restrictions, only single doses of monovalent type 1 OPV were administered to 80% of the target population in 1981, 1982, and 1983. The present incidence of poliomyelitis of 0.1 per 100,000 population represents a 96.7% reduction from the rate during the prevaccine era, when the annual average rate was 4.26 per 100,000. The present aim of poliomyelitis control is to maintain and decrease the present incidence of disease. Future plans are to continue mass vaccination in an attempt to reach small and isolated villages that have been without vaccination and limit possible rural foci of wild poliovirus.

Selective primary health care: strategies for control of disease in the developing world. IX. Poliomyelitis.

Poliomyelitis is an acute viral disease primarily afflicting children. It can be very mild, permanently crippling, or fatal. In the developed nations, poliomyelitis is controlled by the use of trivalent vaccines: killed virus administered by injection and/or attenuated virus administered orally. The latter is cheaper. A combination of the two may be required in some tropical countries. In many developing nations poliomyelitis remains endemic and prevalent, especially in children; 37,747 cases were reported to the World Health Organization in 1979, but greater than 200,000 cases probably occurred. Socioeconomic improvement and public health measures (i.e., immunizations) remain the major strategies for control. While global eradication may be a more distant goal, poliomyelitis could be controlled better. Effective programs for control include safe, efficacious, and inexpensive vaccines; methods for successful management of vaccine delivery systems; commitment and training of health personnel; public education; commitment of funds; and research to improve vaccines and their delivery. The major obstacle to control of poliomyelitis is failure to immunize an adequate number of susceptible children. Development of strategies for immunization is crucial to elimination of poliomyelitis as a major world health problem.

Control of poliomyelitis by pulse immunisation in Vellore, India.

In a simple study into the control of polio in the Third World a town was divided into 16 zones and pulses or oral polio vaccine given at one station in each zone, after extensive publicity about the campaign. Some 62% of children received three doses of the vaccine and the incidence of polio fell dramatically over the study period. It is suggested that this method is applicable to similar communities because it is cheap, effective, and able to be extended to unimmunised communities when resources allow.

Control of Poliomyelitis: A Continuing Paradox

Worldwide control of poliomyelitis efforts have encountered numerous complexities and problems. Although the disease has been eradicated from many geographic areas over the past 25 years it continues to defy control efforts in many tropical countries. This article describes the epidemiology and pathogenesis of polio infection and the mechanisms by which the 2 different vaccines inactivated poliovirus vaccine (IPV) and attenuated live oral poliovirus vaccine (OPV) induce protection against paralytic poliomyelitis. Oral vaccine take rates have been as low as 60% in tropical and semitropical areas in contrast to the almost 100% response characteristic in children in temperate climates. This problem appears to reflect a complex of anatomic physiologic and biochemical changes that accompany malnutrition associated with high rates of intestinal infection and diarrhea. The profound alterations of metabolic and immunologic mechanisms that result from repeated infection may produce a chronic state of imbalance. Lameness surveys in subtropical countries have indicated prevalence rates of residual paralysis in the 5-7/1000 range. OPV is currently being used in the Pan American Health Organization Expanded Program on Immunization and a saturation approach to immunization has been effective in countries such as Cuba. There is some evidence that in densely populated areas with constant introduction and circulation of virulent poliovirus a combined OPV-IPV schedule may be necessary to suppress the disease. Recombinant DNA technology should make it possible to construct safe nonvirulent strains of poliovirus vaccine that have the immunogenic advantages of live replicating viruses without the potential to undergo reversion and cause disease. In the interim it is essential that surveillance of cases and immunity levels of target populations continue.

The immunological response of Nigerian infants to attenuated and inactivated poliovaccines

A comparison was made of the immunity conferred by injected formalin-killed poliomyelitis vaccine and orally administered attenuated poliomyelitis vaccine in Nigerian infants under tropical conditions where interfering enteroviruses have caused poor conversion rates with attenuated poliomyelitis vaccine. Two hundred and thirty infants completed the immunization schedules. The levels of antibodies to polioviruses were assessed before immunization and at periodic intervals during the trial. Seventy-four per cent, 72% and 85% of the children lacked antibodies to poliovirus types 1, 2 and 3 respectively at 6 months if they received no vaccine, the comparative proportions respectively were 52%, 8% and 48% if they had oral attenuated poliovaccine and 2%, 4% and 0% if they had three doses of inactivated poliovaccine. It is suggested that killed poliovaccine incorporated in a quadruple vaccine may have a place in developing countries like Nigeria in the control of diphtheria, tetanus, whooping cough and poliomyelitis.

Erratum: Control of Influenza and Poliomyelitis with Killed Virus Vaccines

In "Control of influenza and poliomyelitis with killed virus vaccines" by J. Salk and D. Salk (4 March, page 834), the footnote to Table 2 should read "Total number of samples from 4866 different children." In Table 6, under year 3, type I, 99.4 and 96.0 should read 88.4 and 86.0 , respectively."

Erratum: Control of Influenza and Poliomyelitis with Killed Virus Vaccines

Erratum: Control of Influenza and Poliomyelitis with Killed Virus Vaccines

Control of Influenza and Poliomyelitis with Killed Virus Vaccines

The requirements for inducing immunity against an infectious disease are outlined, and the application of these requirements to the development of effective vaccines (vaccinology) is discussed. Influenza and poliomyelitis are examined from this viewpoint, and data are presented that demonstrate the effectiveness of killed virus vaccines against these diseases. A comparison between live and killed poliovirus vaccines suggests the desirability of returning to the use of a killed virus vaccine for the eradication of polio. The natural history of influenza and experience with vaccination suggest that influenza might be brought under effective control by routine immunization in childhood with a polyvalent killed virus vaccine potentiated by an immunologic adjuvant.

Trial by Fury: The Polio Vaccine Controversy.

It has been almost a quarter of a century since a paper by Enders, Weller, and Robbins was published in<i>Science</i>entitled "Cultivation of the Lansing Strain of Poliomyelitis Virus in Cultures of Various Human Embryonic Tissues." This report signaled the beginning of modern virology. Since then hundreds of animal viruses have been cultivated in tissue culture, diagnostic tests have been developed, and vaccines have been produced which have markedly reduced the prevalence of certain diseases. One of the great accomplishments of medicine in this or any other century has been the control of poliomyelitis. Most physicians can still remember the fear that swept the United States during the warmer months of the year. It is not surprising that the development of a vaccine against polio was of intense interest to the general public. This interest, kindled by a paralyzed President's remarkable ability to lead a country from a wheelchair,

Non-polio virus interference with oral polio vaccine immunization: possible influence of physical climate and socio-economic status.

In spite of the widespread use of oral polio vaccine (O.P.V.), vaccination programs in many tropical and subtropical countries have apparently failed to provide the expected results in the control of paralytic poliomyelitis (1). Among several factors considered responsible for these unsatisfactory results, an important role has been attributed to the interferences of naturally occurring enteroviral infections on the “take rate” in the intestine, following O.P.V. administration (2,3).KeywordsOral Polio VaccineSubtropical CountryEnteroviral InfectionParalytic PoliomyelitisLive Virus VaccineThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.