Postvaccinal immunity to polio-viruses of children with chronic renal pathology

41 children with chronic renal diseases (with different forms of chronic glomerulonephritis or chronic renal failure) previously vaccinated with 5 to 9 doses of oral poliovaccine (OPV) were examined. Analysis of immunity to polioviruses revealed insufficient serologic protection against all three types of polioviruses compared with general population. Algorithm of yearly serologic examination as well as a schedule of additional vaccination against poliomyelitis depending on chronic renal pathology were developed.     

State of collective immunity to poliomyelitis in Moscow donors

Immunity induced by immunization with oral poliomyelitis vaccine has long been considered to last for life, similarly to immunity developing after infection with wild poliomyelitis virus. Vaccine virus cannot circulate among the immune population for a long time. The vaccination of children against poliomyelitis, carried out in the course of many years, has made it possible to suggest that a considerable number of immune persons were present among the adult population. The examination of 1,030 Moscow donors has revealed that antibodies to poliomyelitis virus of types 1, 2 and 3 were detected in 47.3%, 45.5% and 76.4% of the examinees respectively, the values of the average geometric titers being low. It is known that passages of poliomyelitis vaccine virus through nonimmune persons may result in emergence of revertant viruses with increased neurovirulence. The nonimmune adult population, especially the mothers of vaccinated and revaccinated children, may serve as favorable environment for the circulation of vaccine viruses and the appearance of revertant viruses.     

Distribution of antibodies to poliovirus in the children of a large industrial city

The results of prolonged dynamic observations on the state of herd immunity against poliomyelitis virus in an industrial city are given. The survey covered 1304 children. The data thus obtained, when synchronized according to years, seasons, the age of the surveyed children and the methods used in the survey, indicated that in every age group 20-30% of children had no antibodies to group I poliomyelitis virus and 30% of children had no antibodies to group III poliomyelitis virus. The geometrical mean of antibody titers to different types of the virus fluctuated from 1.8 to 4.6 log2, the lowest value being obtained for the titer of antibodies to type III poliomyelitis virus. During the whole period of immunological control (1974-1978) no mass circulation of poliomyelitis virus and no outbreaks of poliomyelitis were registered despite the fact that a considerable proportion of children having no antibodies to one or several types of the virus was constantly present among the most susceptible part of children.     

Analysis of the results of serum studies of children and adults for antibodies to the poliomyelitis virus in a multiyear effort at vaccinal prevention of this infection

The results of testing the blood sera of children and adults for the presence of antibodies to poliomyelitis have shown the low level of immunity to this infection. The authors believe that the main reasons of the tendency towards the decrease in immunity to poliomyelitis, observed in recent years, are the drawbacks of the vaccinal prevention of this infection and the absence of a differentiated approach to the choice of immunization methods under concrete conditions. Mass immunization against poliomyelitis is recommended, especially in the southern and south-eastern regions of the U.S.S.R.     

The level of postvaccinal immunity to diphtheria, tetanus and poliomyelitis in relation to the number of inoculations]

The work was aimed at the comparative study of the intensity of immunity to diphtheria, tetanus and poliomyelitis, depending on the number of injections of adsorbed diphtheria-pertussis-tetanus (DPT) vaccine and poliomyelitis vaccine, for the purpose of finding out the possibility of reducing the antigenic load given to children without diminishing the intensity of immunity. To determine the level of immunity to diphtheria and tetanus, 1900 children under school age were serologically studied by the micromethod in the passive hemagglutination test. The intensity of immunity to poliomyelitis virus was studied in 333 children by means of the neutralization test. The immunogenic properties of the diphtheria component of adsorbed DPT vaccine were found to be less pronounced than those of the tetanus component of the vaccine, which made it impossible to reduce the antigenic load by decreasing the number of vaccinations against diphtheria. The results of the study of postvaccinal immunity to poliomyelitis suggest that during the first and second year of life the course of vaccination against poliomyelitis may be reduced to 3 injections.     

POLIOMYELITIS VACCINE—Epidemiologic Observations on the Safety and Effectiveness in California in 1955

During the past year California has participated with other states in a nationwide field evaluation of the safety and effectiveness of poliomyelitis vaccine. Among 227,000 children who received Cutter vaccine, and the household contracts of these children, the incidence of poliomyelitis was higher during the early postvaccinal period than in comparable age groups of the population at large. Among 238,000 children who received poliomyelitis vaccine made by other manufacturers early in 1955 no increase in poliomyelitis was observed in the inoculated children or their household contacts.Subsequent observation on over 500,000 additional children vaccinated in California alone since September 1955 with vaccine that was made under revised safety standards has uncovered no evidence of unsafe vaccine. In children who received a single inoculation of vaccine prior to the onset of the poliomyelitis season in 1955 the incidence of paralytic poliomyelitis was about 60 per cent less than in unvaccinated children. Among those who received two inoculations an 85 per cent reduction was observed. The average reduction in paralytic poliomyelitis for the entire vaccinated group was approximately 75 per cent. Data thus far on children vaccinated since September 1955 with poliomyelitis vaccine made by methods now approved indicate that a similar overall effectiveness is still being maintained.     

Immunity to poliomyelitis in adult population of Moscow region. Role of vaccine and wild polioviruses in its formation

Assessment of immunity to poliomyelitis in adults from 8 towns of Moscow region was conducted. Low levels of population immunity against some serotypes of poliovirus in several towns have been found. At the same time, these levels were high and very high in other towns. Measurement of levels of strain-specific antibodies to vaccine and wild polioviruses demonstrated wide circulation of wild polioviruses during past decades which had significant influence on formation of immunity. Substantial number of non-immune adults represents favorable conditions for circulation of vaccine polioviruses after cessation of vaccination, which, in its turn, could result in reestablishment of their neurovirulent properties and subsequent reemergence of poliomyelitis.     

Vaccination coverage in hard to reach Roma children in Slovenia

The results of the retrospective analysis of data on vaccination coverage in the preschool-aged and school-aged Roma children (436 preschool and 551 schoolchildren) in three geographical regions of Slovenia were analyzed to establish the differences concerning coverage for specific vaccinations: poliomyelitis, diphtheria, tetanus, pertussis, measles, mumps and rubella between the two generation. The data were obtained from health records, immunization records (Vaccination booklet) and National Computerized Immunization System (CEPI 2000). Vaccination coverage was calculated by comparing the number of children eligible for immunization with the number of vaccinated children. This article performs the log-rank statistical test, also known as the Mantel-Haenszel test. Log rang test is comparing survival curves for two generations. Preschool-aged Roma children showed higher vaccination coverage than the school-aged Roma generation. There was no significance difference in the generations of preschool aged and school aged Roma children fully vaccinated against poliomyelitis, diphtheria, tetanus and pertussis. Rubella vaccination was significantly lower in the school aged Roma generation. Only 33% of school aged Roma population received two doses of measles, mumps and rubella vaccine. Vaccination coverage of preschool Roma children in Slovenia against poliomyelitis, diphtheria, tetanus, pertussis and MMR (measles, mumps, rubella) were significantly lower then the national vaccination coverage for preschool aged Slovenia children. Many joint efforts will have to be made to improve the vaccination coverage in Roma communities.     

Outside Europe. Is poliomyelitis a serious problem in developing countries?--the Danfa experience.

Children were examined for lameness in the Danfa Project district of rural Ghana to assess the impact of endemic poliomyelitis and to test a widely held hypothesis that paralytic poliomyelitis is relatively rare in such districts (less than 1 per 1000 children affected). The observed prevalence of lameness attributable to poliomyelitis was 7 per 1000 school-aged children, and the annual incidence is estimated to be at least 28 per 100 000 population. Although no evidence for an epidemic was found, these rates are comparable with those in the USA and Europe during the years of severe epidemics and indicate that a high price is being paid in the Danfa district for the natural acquisition of immunity. As a result, immunisation against poliomyelitis has been given high priority. A teacher questionnaire was also tested for use in postal surveys as a rapid means of estimating the prevalence of lamenes attributable to poliomyelitis in countries with a reasonable network of primary schools.     

新型抗结核蛋白亚单位疫苗Ag85A-γ干扰素的免疫效果评价

本研究旨在评价新型抗结核融合蛋白亚单位疫苗Ag85A-γ干扰素(Ag85A-IFN-γ)的免疫效果.在成功表达并纯化了去除Ag85A信号肽的融合蛋白Ag85A-IFN-γ后,将其与免疫佐剂二甲基三十六烷基铵(DDA)混合,皮下免疫C57BL/6小鼠3次,每次间隔2周,末次免疫2周后进行效果评价.采用酶联免疫吸附试验(ELISA)检测血清中IgG、IgG1和IgG2c水平.结果显示,融合蛋白Ag85A-IFN-γ组的IgG水平均高于单独抗原组,且融合蛋白组IgG2c/IgG1 比值显著高于对照组,表明融合蛋白能刺激宿主产生更强烈的体液免疫反应,更倾向于激发T辅助细胞1型(Th1型)免疫反应.流式细胞术检测特异性CD4+和CD8+ T细胞比例,发现Ag85A-IFN-γ组CD8+/CD4+最高,显示该融合蛋白能显著增强CD8+ T细胞增殖.上述结果表明,融合蛋白Ag85A-IFN-γ有望成为有效的新型抗结核融合蛋白亚单位疫苗.     

Cross-immunity between Haemonchus contortus and Trichostrongylus colubriformis in sheep

Cross-protective immunity between the nematode parasites, Haemonchus contortus and Trichostrongylus colubriformis, was examined in sheep vaccinated with irradiated larvae of either species. Secondary immunological responsiveness stimulated in this manner protected only against challenge infection with the species used for vaccination. Significant cross-protective immunity was not observed. Titres of serum antibody to an extract of adult but not infective larval T. colubriformis reflected the specificity for protective immunity. Immediate hypersensitivity skin reactions to nematode extracts did not reflect the antigen-specificity for protective immunity.     

Impact of vaccination on the infectious diseases epidemiology: example of pertussis

Several vaccines are now routinely used since fifty years in different developed countries. Their principal impact has been to decrease morbidity and mortality of the infectious diseases they are targeting. One disease, smallpox, is eradicated, poliomyelitis will be soon, diphteria is controlled in several countries but pertussis is still endemic although an efficacious vaccine was used. Why? Pertussis is an example of an infection for which the immunity of the population has changed after the introduction of generalized vaccination with killed whole cell pertussis vaccines, from a natural immunity due to infection to different types of vaccine-induced immunity. These different types of immunity have changed the protection against infection, disease and transmission. The impact of the generalized vaccination in a human population has been an important change in the epidemiology of the disease. In fact, a child-to-child transmission observed before the introduction of vaccination is now replaced by an adolescent-adult to infant transmission. The major consequence is an increase in the mortality and morbidity in non vaccinated infants mostly contaminated by their parents. Researches undertaken on the agent of the disease, the bacterium, Bordetella pertussis, conducted to the development of subunits vaccines, efficacious and better tolerated by infants than whole-cell vaccines. Many developed countries decided to change vaccines but also to add vaccine boosters for adolescents and adults in order to stop the transmission of the disease to infants. However, even after 15 years of studies in many countries, pertussis is still underestimated in adults and generalized adult vaccination remains difficult. The new goal now is to give information to medical students and health care workers in general in order to increase adolescent and adult's vaccination coverage.     

Annual vaccination against influenza virus hampers development of virus-specific CD8⁺ T cell immunity in children

Infection with seasonal influenza A viruses induces immunity to potentially pandemic influenza A viruses of other subtypes (heterosubtypic immunity). We recently demonstrated that vaccination against seasonal influenza prevented the induction of heterosubtypic immunity against influenza A/H5N1 virus induced by infection with seasonal influenza in animal models, which correlated with the absence of virus-specific CD8(+) T cell responses. Annual vaccination of all healthy children against influenza has been recommended, but the impact of vaccination on the development of the virus-specific CD8(+) T cell immunity in children is currently unknown. Here we compared the virus-specific CD8(+) T cell immunity in children vaccinated annually with that in unvaccinated children. In the present study, we compared influenza A virus-specific cellular and humoral responses of unvaccinated healthy control children with those of children with cystic fibrosis (CF) who were vaccinated annually. Similar virus-specific CD4(+) T cell and antibody responses were observed, while an age-dependent increase of the virus-specific CD8(+) T cell response that was absent in vaccinated CF children was observed in unvaccinated healthy control children. Our results indicate that annual influenza vaccination is effective against seasonal influenza but hampers the development of virus-specific CD8(+) T cell responses. The consequences of these findings are discussed in the light of the development of protective immunity to seasonal and future pandemic influenza viruses.     

Immune-priming in ant larvae: social immunity does not undermine individual immunity

Social insects deploy numerous strategies against pathogens including behavioural, biochemical and immunological responses. While past research has revealed that adult social insects can generate immunity, few studies have focused on the immune function during an insect''s early life stages. We hypothesized that larvae of the black carpenter ant Camponotus pennsylvanicus vaccinated with heat-killed Serratia marcescens should be less susceptible to a challenge with an active and otherwise lethal dose of the bacterium. We compared the in vivo benefits of prior vaccination of young larvae relative to naive and ringer injected controls. Regardless of colony of origin, survival parameters of vaccinated individuals following a challenge were significantly higher than those of the other two treatments. Results support the hypothesis that ant larvae exhibit immune-priming. Based on these results, we can infer that brood care by workers does not eliminate the need for individual-level immunological responses. Focusing on these early stages of development within social insect colonies can start addressing the complex dynamics between physiological (individual level) and social (collective) immunity.     

Assessment of the separate elements of an epidemiological overview of poliomyelitis today

The materials on the epidemiological supervision of poliomyelitis in a large city, carried out in 1972-1981, are presented. Two periods differing in morbidity rate, in the level of population immunity to poliomyelitis and in the activity of the poliovirus circulation are defined. The supervision of poliomyelitis is shown to be capable of influencing the course of the epidemic process of this infection provided that the individual elements of such supervision are correctly evaluated in different epidemic situations.     

THE PRECIPITATION OF CLINICAL POLIOMYELITIS BY INJECTIONS

In records of 1,321 cases of poliomyelitis in the city of Los Angeles in 1948, notation was made as to whether or not the patient had been vaccinated against smallpox or had received an injection of one kind or another in the period preceding the onset of poliomyelitis.In children under 12 years of age, the incidence of poliomyelitis was slightly higher among those who had had recent vaccination or injection than among those who had not, and the incidence of paralysis was slightly greater also. However, the disparities were not considered statistically significant. They were not wide enough to warrant withholding immunization against other serious diseases on the strength of the possibility that in so doing a slight reduction in the incidence of crippling poliomyelitis might be effected.     

Congo polio immunisation campaign gets go ahead

Since the World Health Organization (WHO) set a goal in 1988 of eradicating polio worldwide by 2000, the incidence of the disease has declined by 90% around the world, with national immunization days conducted in more than 120 countries. More than 450 million children were immunized in 1998 alone. Now, with only about 5000 annual cases of polio occurring, complete eradication can be achieved. To that end, and in a first-ever initiative, the heads of the World Health Organization (WHO) and UNICEF, jointly appealed to UN Secretary General Kofi Annan for help in bringing immunization against polio to children in war-torn Democratic Republic of Congo. Mr. Annan subsequently announced an initiative to negotiate several special ceasefire agreements in Congo so that approximately 10 million children under age 5 years can be immunized against poliomyelitis during July-September 1999. Both the president of Congo, Laurent Kabila, and rebel leaders have given their preliminary assurances that weapons will be laid down while Congolese children are sought out and vaccinated. A joint WHO-UNICEF planning mission will travel to Kinshasa in April to advise the Congolese Ministry of Health, which has main responsibility for the areas under governmental control. The $15 million project is expected to cover 3 rounds of immunization to bring population immunity to the highest possible level.     

Vaccination against polio should not be stopped

The striking 50-year-long decline in the incidence of poliomyelitis has stalled in the past 7 years, which has led to calls for an urgent re-assessment of eradication and post-eradication campaign strategies. The current plan of eliminating the circulation of wild poliovirus so that further immunization will be unnecessary does not take into account recent scientific data and political realities that limit the likelihood that this strategy can sustain prevention of the disease. It is crucially important that high levels of population immunity are maintained against polio in the foreseeable future.     

Strain-specific antibodies as an indicator of the circulation of wild poliomyelitis viruses and their role in the formation of collective immunity in the population

Essential differences in the intensity of collective immunity to poliomyelitis in the donors of Moscow and Kaluga were established. To find out the nature of high characteristics of collective immunity to poliovirus, types 1 and 2, in the donors of Kaluga, strain-specific antibodies to wild and vaccine polioviruses were studied. In a considerable number of donors strain-specific antibodies to poliovirus, types 1 and 2, were detected. This made it possible to presume a sufficiently wide circulation of these viruses among the population of the city in the middle of the 20th century and, as a consequence, high level of collective immunity appeared. Strain-specific antibodies to poliovirus of type 3 were rarely detected. This made it possible to suggest that the circulation of viruses of this type among the population was limited. Immunity to viruses of this type was due only to immunization. For this reason the characteristics of collective immunity in the donors of Moscow and Kaluga coincided. The detection of strain-specific antibodies to poliomyelitis virus allowed to retrospectively form the opinion of the spread and time of the circulation of wild poliomyelitis viruses in the population.     

Immunoprophylaxis of poliomyelitis in Ukraine with the use of inactivated vaccine

In connection with the cessation of the circulation of "wild" poliovirus on the territory of the European region, including Ukraine, the strategy of the vaccinal prophylaxis of poliomyelitis is reviewed. Its main aims are the creation of a high level of the specific protection of the population, the prophylaxis of vaccine-associated paralytic poliomyelitis and a decrease in the intensity of the circulation vaccine polioviruses. These aims may be achieved only by the inclusion of vaccinations with inactivated poliomyelitis vaccine (IPV) into the immunization schedule. IPV "Imovax Polio" produced by the firm "Aventis Pasteur" (France) has been shown to have low reactogenicity and high effectiveness, especially with respect to type 3 poliovirus, under the conditions of Ukraine. On the basis of our studies all children, starting from the age of 3 months, are recommended to be vaccinated first with two injections of IPV, followed by further immunization with oral vaccine.