The duration and intensity of measles immunity after a repeat inoculation against this infection

Controlled study lasting 6 years showed that booster immunization against measles was highly effective in children remaining seronegative, i. e. susceptible to this infection, after primary immunization: E = 97.5 +/- 0.12% (K = 35.7). Annual serological examination of children given booster immunization revealed that 87.6% of initially seronegative children retained specific antihemagglutinins for 5.5 years (the term of observation). The effectiveness of booster immunization against measles did not depend on the age when primary immunization had been made.     

The protective role of postvaccinal immunity in mumps in children

The immunological study of children with infectious parotitis (IP) without complications and with such complications as pancreatitis, meningitis or orchitis in the glandular form was carried out. In accordance with the previously proposed principle, 4 types of immune response (IR) were established on the basis of differences in initial resistance and the IR profile: cell-mediated immunity (types I and III) and humoral immunity (types II and IV). The patients included nonvaccinated children, as well as children vaccinated on epidemic indications, 3-6, 7-9, 10 and more years before infection. The comparative analysis of the number of IP cases with and without complications in the groups of children, divided according to their immunization history and the type of IR, revealed that postvaccinal immunity in children vaccinated on epidemic indications (less than a month ago) or 3-6 years before infection had protective potential, sufficient for the prevention of complicated forms of IP. Immunity obtained 7-9 years ago was effective for the protection from IP complications only in cell-mediated, but not humoral IR. Postvaccinal immunity obtained more than 10 years ago did not ensure the decrease in the occurrence of complicated forms of IP (in comparison with that in nonvaccinated patients) in children with any type of IR.     

Immunoepidemiological observations on the duration of post-vaccinal immunity in children vaccinated against measles

In the course of 4 years the authors carried out an immunological and epidemiological observation over 4719 children which attended creches, kindergartens and schools, and were vaccinated with live measles vaccines L-16 and ASC in 1967--1972. A stable persistence of immunity was revealed in the majority of children vaccinated against measles which responded to the vaccination by the formation of humoral antibodies. Among these groups an insignificant number of persons with the appearance of measles sensitivity was noted during the observation period. The quality of the preparation, conditions of its storage, use, and different errors during the vaccination influenced the efficacy of the vaccination. Children immunized with the low-immunogenic series of the vaccine whose blood sera failed to display any specific antibodies in the reaction with 1 AU of the antigen, as a rule, were the ones that contracted the disease.     

Evaluation of postvaccinal pertussis immunity by using immunoenzyme analysis

The effectiveness of adsorbed DPT vaccine manufactured in the USSR, evaluated by its capacity of inducing the formation of the main classes of immunoglobulins and by the duration of immune response to the acellular complex of protective antigens (pertussis toxin and agglutinogen-2), was studied with the use of modified EIA. Out of 273 children immunized with adsorbed DPT vaccine in the course of this study, 87.2% had IgG-antibodies, 14.1% had IgA-antibodies and 3.2% of the children had IgM-antibodies. The level of immunity in children having received the full course of immunization with adsorbed DPT vaccine was significantly higher in comparison with children given only the primary course of immunization and nonimmunized children of the same age. Antipertussis immunity was found to decrease two years after the completion of the course of immunization with adsorbed DPT vaccine and in children over 5-6 years of age. Adsorbed DPT vaccine prevented the disease, but not infection. The level of postinfection immunity was higher than that of postvaccinal immunity.     

The effects of maternal immunity and age structure on population immunity to measles

Theoretical Ecology - Measles was successfully eradicated in the Pan-American Health Region in 2002. However, maintenance of elimination in parts of Africa, Europe, the USA, and other regions is...     

Proteus peritonitis-bacteremia in mice--a model for studying postvaccinal Proteus immunity

The dynamics of the formation of postvaccinal immunity after immunization with preparations obtained with the use of hydroxylamine (HA) preparations from Proteus strains of different O serogroups, Salmonella minnesota Re-mutant and the common antimicrobial antigen isolated from Escherichia coli 14 has been studied on mice with Proteus peritonitis-bacteremia used as a model. The study has revealed that intraperitoneal immunization with Proteus HA preparations stimulates the phagocytic activity of peritoneal mononuclear cells in mice and induces an increase in the titers of specific O antibodies. Proteus antigens ensure the formation of anti-Proteus immunity, preventing the death of the animals from peritonitis-bacteremia. The protection of mice from such infection resulting from the injection of the common antigens of gram-negative bacteria is considerably less. These data are indicative of the possibility of using Proteus peritonitis-bacteremia as a model for the study of the protective potency of Proteus vaccines.     

Duration and intensity of postvaccinal immunity to plague in experimental animals]

Experiments were conducted on guinea pigs and Papio hamadryas; it was shown that a reduction of the intensity of postvaccinal immunity occurred at various periods after a single vaccination. In inhalation method of immunization in guinea pigs it decreased in 6 months 135 times, in monkeys in one year--133 times. However, at the mentioned periods vaccination provided protection of 50% of the animals from infection with Past. pestis in a dose constitutin 20 to 25 aerosol LD50 for nonimmunized animals. Despite the more pronounced (57--640 times) reduction of the intensity of immunity than in the animals vaccinated by inhalation, in the subcutaneously vaccinated guinea pigs in subcutaneously infected with Past. pestis protection level remained high (resistance index in 3 and 6 months constituted 37.10(6) and 3-3-10(6), respectively).     

The results of multiyear observations on the duration of the maintenance of immunity in those vaccinated and revaccinated against and recovered from measles

The results of 5-year observations on the duration of immunity to measles virus in persons vaccinated and revaccinated against measles, as well as in persons having had this infection, are presented. The intensity of immunity was determined in the same persons with the use of the passive hemagglutination test. The study revealed differences in the formation, intensity and duration of postvaccinal immunity. A significant decrease in the concentration of antibodies over the period of 5 years was established in 50.0-52.3% of vaccines. Revaccination with live measles vaccine is an effective measure for enhancing immunity to measles virus in persons with initial antibody titers less than 1:10-1:20, but revaccination made in a single injection is not sufficient for the stable maintenance of measles morbidity at the sporadic level. Postinfectious immunity is characterized by stability and has no tendency towards decrease. Persons having had measles have no need in additional measures irrespective of the time elapsed after the disease.     

儿童麻疹初免时间的探索研究

通过对不同月龄儿童母传抗体衰减规律以及接种成功率的研究,论证麻疹初免时间提前的必要性与可能性,以及提前多少为合适,为进一步的科学决策提供依据。2004年7月至2005年6月,从鹰潭市疾病控制中心预防接种门诊部随机抽取5～8月龄未注射麻疹疫苗的婴儿各100名,检测其麻疹抗体的滴度,研究婴儿麻疹抗体衰减的规律,然后给受检婴儿接种麻疹疫苗0.5ml。初免一个月以后再检测婴儿体内的抗体滴度,研究婴儿对麻疹疫苗的免疫应答与月龄大小的关系,以及与初免前抗体的关系。结果认为儿童麻疹的初免时间应提前到6月龄为宜。     

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.     

Effectiveness of pertussis vaccination and duration of immunity

Background:A resurgence of pertussis cases among both vaccinated and unvaccinated people raises questions about vaccine effectiveness over time. Our objective was to study the effectiveness of the pertussis vaccine and characterize the effect of waning immunity and whole-cell vaccine priming.Methods:We used the test-negative design, a nested case–control study with test-negative individuals as controls. We constructed multivariable logistic regression models to estimate odds ratios (ORs). Vaccine effectiveness was calculated as (1 – OR) × 100. We assessed waning immunity by calculating the odds of developing pertussis per year since last vaccination and evaluated the relative effectiveness of priming with acellular versus whole-cell vaccine.Results:Between Dec. 7, 2009, and Mar. 31, 2013, data on 5867 individuals (486 test-positive cases and 5381 test-negative controls) were available for analysis. Adjusted vaccine effectiveness was 80% (95% confidence interval [CI] 71% to 86%) at 15–364 days, 84% (95% CI 77% to 89%) at 1–3 years, 62% (95% CI 42% to 75%) at 4–7 years and 41% (95% CI 0% to 66%) at 8 or more years since last vaccination. We observed waning immunity with the acellular vaccine, with an adjusted OR for pertussis infection of 1.27 (95% CI 1.20 to 1.34) per year since last vaccination. Acellular, versus whole-cell, vaccine priming was associated with an increased odds of pertussis (adjusted OR 2.15, 95% CI 1.30 to 3.57).Interpretation:We observed high early effectiveness of the pertussis vaccine that rapidly declined as time since last vaccination surpassed 4 years, particularly with acellular vaccine priming. Considering whole-cell vaccine priming and/or boosters in pregnancy to optimize pertussis control may be prudent.Whooping cough, or pertussis, is a highly contagious respiratory infection that has been inadequately controlled compared with other vaccine-preventable diseases. The incidence of pertussis in Canada decreased from 156 cases per 100 000 population during the prevaccination era to a historic low of 2.0 per 100 000 in 2011, increased to 13.9 in 2012, and then decreased to 3.6 in 2013.¹Ontario, Canada’s most populous province with a population of 13.5 million in 2013, experienced a localized outbreak in 2012. This outbreak started in a largely unvaccinated religious community and disproportionately affected infants, but then spread to the general population and mostly involved adolescents.² Consequently, the outbreak raised questions about product-specific vaccine effectiveness and waning immunity.Pertussis vaccines have been available in Ontario for more than 70 years. In 1997, owing to concerns about safety and effectiveness, acellular pertussis vaccine replaced the whole-cell product that had been in use since 1984.^3–5 In Ontario, only the 5-component acellular vaccine (containing pertussis toxoid, filamentous hemagglutinin, pertactin, and fimbriae types 2 and 3) has been available for infants and toddlers. Vaccination against pertussis is recommended at 2, 4, 6 and 18 months, and at 4–6 years. In 2003, an adolescent dose at 14–16 years was introduced, and in 2011, a program was started for single-dose adult vaccination against pertussis.⁶Other jurisdictions in Canada, the United States and Australia have reported lower effectiveness with the acellular product and rapidly waning immunity.^7–11 Canada has a unique history of using a whole-cell vaccine with lower effectiveness, and also has different secular trends in pertussis incidence and vaccination coverage, necessitating local evaluation of the effectiveness of the pertussis vaccine to inform vaccination policy. Our objective was to study the effectiveness of the pertussis vaccine in Ontario while characterizing the effect of waning immunity and whole-cell vaccine priming.     

The adaptive potential of human immunity during strength training

Quantitative and functional characteristics of human T-and B-cell-related immunity and natural cytotoxicity were studied during nine-week strength training. Long-term classic strength training and low-intensity strength training without relaxation did not change the peripheral blood contents of the main subpopulations of immunocompetent cells, the phytohemagglutinin-induced proliferative activity of T lymphocytes, serum levels of immunoglobulins A, M, and G (IgA, IgM, and IgG, respectively) and the cytotoxic activity of natural killer cells. At the same time, training was accompanied by activation of the immune system, which was evident from increased counts of CD25⁺ lymphocytes observed in the peripheral blood and in the mitogen-stimulated and nonstimulated cell cultures, as well as from the higher spontaneous and mitogen-induced productions of IgA, IgM, and IgG by B lymphocytes.