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Indian Pediatrics. 2007 Oct 17; 44(10):792-793.Asia accounts for approximately 90% of all rabies fatalities. WHO surveys reveal that half of deaths occur in children and only one third of them receive post exposure treatment (PET) majority being males. Many of these exposures are never reported as a child may be alone with the dog/may not impart significance to few abrasions/may be scared of some painful injections following dog bite and not report it to his caretakers deliberately. Children are more vulnerable to get dog bites as they tend to play with/tease them frequently and can be easily overpowered by dogs. Incubation period also tends to be shorter due to their lesser body surface area and frequent bites on head and neck because of small physique. (excerpt)
Clinical and Experimental Immunology. 1978 Aug; 33(2):360-375.Since guidelines for safety evaluation of antifertility vaccines do not exist, this WHO report attempts to define the parameters to be examined and the methodology which might be used for such a safety assessment. In principle, antifertility vaccines may: 1) prevent sperm transport and/or fertilization; 2) prevent or disrupt implantation; and 3) prevent blastocyst development. Potential advantages of this immunological approach to fertility regulation include: 1) possibility of infrequent administration, possibly by paramedicals; 2) use of antigens or antigen frangments that are not pharmacologically active; and 3) the possibility of large-scale synthesis and manufacture of vaccine at relatively low cost in the case of antigens of known chemical structure. To evaluate the efficacy and safety of placental antigen vaccines, placental antigens used should not possess significant immunological similarity with tissue other than placenta. Carriers or haptens may require structural remodifications of placental molecules to overcome natural immunological tolerance. Adjuvants may be needed to enhance the immune response required. Quality-control procedures for vaccine component production include tests for: 1) purity; 2) toxicity; 3) sterility; and 4) shelf-life. Acute, subacute, and chronic toxicity testing in animals is described for it must be performed separately for the haptenated antigen or conjugate and adjuvant. Such tests would include hematological parameters, blood chemistry, urinanaylsis, gross pathological and organ weight analysis, and ophthalmological tests. Animal models are suggested. Means of monitoring the immune reponse and potential hazards of immunization (e.g., allergy or autoimmune disease) are discussed. The rationale and protocol for safety and efficacy studies of human chorionic gonadotropin-peptide vaccine receive similar attention, with emphasis on tests to be performed before human clinical trials can start.
Geneva, WHO, 1973. (WHO Technical Report Series No. 520) 34 p.After summarizing current WHO research directed at the control of male fertility focusing on 1) gametogenesis and ultrastructure of the testis; 2) cytogenetic aspects; 3) hormonal regulation; 4) epididymal function (the maturation and preservation of spermatozoa); 5) vas deferens; and 6) semen analysis; recommendations for further research in the area are made. Studies are required on the following aspects of reproductive function in the male: 1) structural and cytochemical organization of the various classes of germ cells in humans and nonhuman primates; 2) interstitial tissues and the components of the blood-testis barrier and their role in the regulation of gametogenic function of the testis; 3) structural and functional state of the testis during growth and development, during aging, and in most histopathological conditions leading to partial or complete sterility; 4) the role of meiotic chromosome aberration in degeneration of germ cells; 5) role of abnormal chromosomes as an etiological factor in male infertility; 6) binding and metabolism of androgens and their effects on the seminiferous tubule; 7) role of gonadotropins, particularly follicle stimulating hormone (FSH), in regulation of spermatogenesis; 8) identification of tubular factors involved in regulation of FSH secretion; 9) elucidation of epididymal function in a number of species; 10) characteristics of sperm surface; 11) nature of epididymal plasma and the factors that control it; 12) anatomy, physiology, and functional role of human vas deferens, with emphasis on blood supply; 13) effect of vasectomy on male reproductive function and possible immunological sequelae of this operation; 14) relationship between fertility and such characteristics of sperm as number, motility, and morphology; 15) biochemical characteristics of the nucleus, acrosome, and midpiece of sperm, and their relationship to sperm motility and fertility; 16) chemical nature of substances secreted specifically in different accessory sex organs; 17) the possible relationship between autoimmune phenomenoa and testicular disease; and 18) immunological sequelae of vasectomy. In addition, studies on the cryobiology of human and animal sperm are expected to yield information on the biology of sperm.
Geneva, World Health Organization, 1966. (Technical Report Series No. 334.) 21 p.A WHO Scientific Group on Immunological Aspects of Human Reproduction met in Geneva October 4-9, 1965. Topics of discussion included: 1) immunology of human gonadotropins; 2) sperm and seminal fluid; 3) blood group antigens and human reproduction; and 4) maternal-fetal immunological interactions. It was concluded that further investigations are required to study: 1) the correlation between physiocochemical, biological, and immunological criteria for the purity of antigens concerned in human reproduction; 2) the chemical structure of hormones concerned with reproduction, with special reference to the biologically active sites and the nature of antibodies against these active sites; 3) production of antibodies to the gonadotropins by the use of adjuvants and/or chemically modified gonadotropins; 4) modification of hormones from other species to render them active but non-antigenic in man; 5) the use of immunological methods for assisting in the detection of the time of ovulation: these could aid in the control of fertility and in the treatment of infertility; 6) the development of strains of animals of high immunological competence; 7) characterization of the male antigens responsible for various immunological phenomena in males; 8) characterization of male antigens responsible for inducing circulating antibodies and reducing the fertility of immunized females; 9) the nature and biological significance of the antagglutinins; 10) possible ways of interfering with the transmission of antibodies in man; and 11) the possible occurrence of specific antitrophoblastic antibodies in pre and postpartum. Other research needs are also outlined.
NATION'S HEALTH. 1994 Mar; 12.Scientists have advanced in the struggle to develop a vaccine against malaria, which kills up to one million children a year in Africa and causes 300-500 million clinical cases worldwide. The vaccine is named SPf66, and it has passed new human trials in an endemic region of Africa. Preliminary results show that the vaccine induces a long immune response against malaria without any adverse side effects. These results have made it possible to advance to the ongoing final phase of human tests, which will determine whether the vaccine actually reduces the number of malaria attacks. If the tests are successful, an effective vaccine could be available for wide scale use by 1998. Tore Godal, the director of the UN development Programme/World Bank/World Health Organization Special Program for Research and Training in Tropical Disease, said that the test demonstrated that they were more than halfway to developing the first ever effective malaria vaccine. There are still scientific obstacles to overcome, but the search can be concluded as long as the flow of research funds continues. Malaria control through insecticides to kill the disease-carrying mosquitoes has been effective across much of the world, but these methods have not been practical or cost effective across much of Africa or in parts of Latin America and Asia, making a vaccine the best alternative. The new tests are taking place in Tanzania, where inhabitants can suffer an average of 300 bites from malaria-infected mosquitoes a year. SPf66 may be on only one component of malaria vaccine strategy, which itself is only one component of a full-scale malaria control strategy. The Global Malaria Control Strategy, adopted by governments and the Word Health Organization in 1992, emphasized early diagnosis, appropriate treatment with anti-malarial drugs, and selected preventive measures, including mosquito control.
[Immunocontraception -- current research status] Immunkontrazeption -- jetziger Stand der Forschung.
GYNAKOLOGE. 1990 Jun; 23(3):178-83.In 1972, WHO advanced the idea of a safe and reversible birth control vaccine lasting 1-2 years. This contraceptive could utilize the connection of sperm antibodies and sterility by active immunization (foreign antigens) and passive immunization (monoclonal antibodies). After long experimentation, a vaccine was introduced in 1984 based on the carboxyl-terminal peptide (CTP) of the beta subunit of human chorionic gonadotropic (HCG) couples with a diphtheria toxoid (DT) and mixed with a muranyldipeptide (MDP) adjuvant called 109-145-CPT-beta- HCG:DT mixed with MDP. When given to baboons, the pregnancy rate fell to 4.6% vs. the 70% rate in untreated animals. Out of 15 women with previous tubal ligations, 14 showed production of specific antibodies: in Group A, 80 ug beta-HCG antigen was injected 4 times 2 weeks apart, while Group B received 240 ug only twice, 1 month apart. Side effects included edema, adnexal pain, DNA-antibody increase, plasmacortisone fluctuations, and liver enzyme changes. Later refinements eliminated blood chemistry changes, and injection 4 times produced specific antibody formation after 500 days. Immunization against follicle stimulating hormone (FSH) produced reversible sterility in rhesus monkeys after 4 and 1/2 years; however, the controversial role of testosterone in spermatogenesis terminated this approach. The inactivation of LDH-C4-lactatedehydrogenase produced only reduction of fertility in rabbits and baboons. However, 25 guinea pigs immunized twice, 1 month apart, with PH 20, a sperm-coating antigen, exhibited 100% infertility compared to the fact that 94% of untreated controls had a litter. Zona-pellucida antigens affected not only the egg cells but also the ovarian follicles. Among embryonal antigens, F-9-oncofetal antigens reduced fertility in mice but produced teratocarcinoma. Passive immunization by mono- and polyclonal antibodies against early- pregnancy factor terminated pregnancy in mice, suggesting another possible avenue for immunocontraception.
Bulletin of the World Health Organization. 1978; 56(2):179-192.Strong evidence that specific immunogenic components of the reproductive system exist that are not represented in other body systems has led to efforts to develop an acceptable vaccine for fertility regulation. The aim is to create a vaccine administered infrequently by trained technicians outside the clinical environment. For safety and practical reasons, an approach using active immunization with a vaccine is preferred to passive immunization with antibodies. In current research with sperm antigens, a lactate dehydrogenase isoenzyme (LDH-X), an enzyme normally present on the sperm surface, reduced fertility in mice and rabbits. However, significant embryo mortality occurred. Other sperm antigens have been tested and rejected. Most of the research on ovum antigens is directed toward the zona pellucida, and work is in progress to isolate experimental quantities of specific zona pellucida antigens. Antibodies to human zona are reported to react with pig zona and vice versa, providing a model system. Antibodies to whole-placenta homogenates reportedly disrupt pregnancy in several laboratory animal species, and 2 placenta-specific proteins are potential antigens since antibodies to them do not react with any other tissue so far tested. Of 3 protein hormones isolated from placental tissue, 2 are potential antigens. The possible hazards of antifertility vaccines can be divided into 2 categories: problems related to immunization and problems caused by antibodies produced.