Four and 6 months after immunization, we observed that the decrease of antibody levels induced by the MenB vaccine was more marked compared to the fall of antibodies to DT. At 4 months after immunization with DTP vaccine, protective DT antibody levels were present in all DTP-vaccinated mice but only in 20% of mice immunized against MenB. After 6 months of primary immunization, about 70% of the animals still had protective neutralizing DT antibodies, but none had significant bactericidal antibodies to MenB. A long-lasting antibody-secreting cell response was also seen for the Figure 3. Neutralizing antibody levels to diphtheriatoxoid (DT) of mice immunized with the diphtheria-tetanus-pertussis (DTP) vaccine. The lines show the average antibody titers detected at (A) 14 days after each vaccine injection during the primary immunization schedule and (B) before (pre-booster) and 14 days after boosting at 2, 4, and 6 months (mo) after the primary immunization schedule. The dashed line in A and B represents the protective neutralizing antibody level (.0.1 IU/mL). Points represent each individual antibody level, which was tested at least twice for each sample. *P , 0.05 compared to 2 doses. #
The construction of a hexahistidine-tagged version of the B fragment of diphtheria toxin (DTB) represents an important step in the study of the biological properties of DTB because it will permit the production of pure recombinant DTB (rDTB) in less time and with higher yields than currently available. In the present study, the genomic DNA of the Corynebacterium diphtheriae Park Williams 8 (PW8) vaccine strain was used as a template for PCR amplification of the dtb gene. After amplification, the dtb gene was cloned and expressed in competent Escherichia coli M15™ cells using the expression vector pQE-30™. The lysate obtained from transformed E. coli cells containing the rDTB PW8 was clarified by centrifugation and purified by affinity chromatography. The homogeneity of the purified rDTB PW8 was confirmed by immunoblotting using mouse polyclonal anti-diphtheriatoxoid anti- bodies and the immune response induced in animals with rDTB PW8 was evaluated by ELISA and dermonecrotic neutralization assays. The main result of the present study was an alternative and accessible method for the expression and purification of immunogenically reactive rDTB PW8 using commercially available systems. Data also provided preliminary evidence that rabbits immunized with rDTB PW8 are able to mount a neutralizing response against the challenge with toxigenic C. diphtheriae.
All individuals received one dose (0.5 mL) of Td vaccine (Butantan Institute, São Paulo, SP, Brazil) containing 10 Lf (Limes flocculation unit) per dose of tetanus toxoid and 2 Lf per dose of diphtheriatoxoid adsorbed onto aluminum toxoid and with thimerosal as a preservative. Blood samples were collected from all participants immedi- ately before vaccination and 30 days after the procedure. Serum was separated and stored at -20ºC until analysis. Antibodies against tetanus and diphtheria were meas- ured by the double-antigen ELISA test, as previously described (7).
7. Kretsinger K, Broder KR, Cortese MM, Joyce MP, Ortega-Sanchez I, Lee GM, et al. Preventing teta- nus, diphtheria, and pertussis among adults: use of tetanus toxoid, reduced diphtheriatoxoid and acellular pertussis vaccine recommendations of the Advisory Committee on Immunization Practic- es (ACIP) and recommendation of ACIP, supported by the Healthcare Infection Control Practices Advi- sory Committee (HICPAC), for use of Tdap among health-care personnel. MMWR Recomm Rep 2006; 55(RR-17):1-37.
Autologous and allogeneic bone marrow transplantation (BMT) re- cipients lose immune memory of exposure to infectious agents and vaccines accumulated through a lifetime and therefore need to be revaccinated. Diphtheriatoxoid, tetanus toxoid, pertussis vaccine (children <7 years old), Haemophilus influenzae type b conjugate, 23- valent pneumococcal polysaccharide, inactivated influenza vaccine, inactivated polio vaccine and live-attenuated measles-mumps-rubella vaccine are the currently recommended vaccines to be included in a vaccination program after BMT. For most of them, the best time to vaccinate, the number of vaccine doses and/or the duration of immu- nity after vaccination have not been established. Vaccination proto- cols vary greatly among BMT centers, suggesting that the lack of sufficient data has not permitted the formulation of reliable recom- mendations. The use of other vaccines and the perspectives for differ- ent vaccination protocols are analyzed in this review.
Groups of eight mice (FVB; female; 3–5 weeks of age) were immunized intraperitoneally (IP) with 0.4 ml of heat-inactivated (56 uC for 30 min) immune goat sera raised to dPNAG-ClfA, dPNAG-DT (dPNAG conjugated to diphtheriatoxoid protein) vaccines, or NGS 48 and 24 h before infection. Mice were challenged IV with the S. aureus strains Newman (4.3610 7 CFUs), MN8 (8.6610 6 CFUs), 476 (6.7610 5 CFUs), Newman Dica (7.5610 7 CFUs) or DU5852 (3.5610 7 CFUs), at the doses indicated, in 0.2 ml of PBS. Two hours later mice were sacrificed and samples of 0.5 ml blood obtained from the heart, mixed with 20 m l of heparin (Sigma), and plated onto TSA plates. Bacteremia was quantified by colony counts after overnight growth and values expressed as CFU/ml of blood.
The antigen Dtxd (Diphtheriatoxoid) was a gift from Dr Célia S. Takata , Instituto Butantan (Lot AnD/PAG 14/05, 1650 Lf/mL, SPC (Soy phosphatidylcholine) was purchased from Avanti Polar Lipids (USA); Chi (Chitosan, low molecular weight, deacetylation degree 75-85 %) and PVA (poly- vinilic alcohol, Mw 127 kDa), Cho (cholesterol); Mu (Types1S and III mucin) were obtained from Sigma and Aldrich, respectively. All other chemicals and solvents used were of analytical grade. Equipments: Probe sonifier Branson, model 450; rotatory evaporator Tecnal TE-210; Zetasizer (Brookhaven Zeta Pals); spectrophotometer Pharmacia Ultraspec 2000, TEM, transmission electronic microscope LEO model 906E, JEOL 100CX electronic microscope, criofracturer JEOL JED-9000 and an ELISA automatic reader Titerteck Multiscan MCC/340 (Labsystems).
Despite the dramatic decline in the incidence of diphtheria after routine childhood immunization (2), studies from Europe (13) and North America (14) have shown that the adult population is not fully protected against the disease. During an epidemic in Eastern Europe the highest mortality rate (62%) was detected among persons aged 41 to 64 years (15). Nowadays, booster doses of diphtheriatoxoid in Brazil and many other countries are recommended every 10 years for adults, but this recommendation is not regularly enforced (6,15).
For children under six years of age: DPT, consisting of tetanus toxoid, diphtheriatoxoid and pertussis component. Should be given as three initial doses at 4–8-week intervals, with at least one month between doses. Ideally, the doses should be given at the ages of two, four and six months. Two booster doses should be given, with the irst at the age of 15 months and the second between the ages of four and six years. Adolescents For adolescents who previously received three or more doses of DPT, DT or dT, give one booster dose.
Some examples of preventive interventions (the type which provide the greatest average gain in lifespan at the populational level) can be cited, such as immunization against diphtheria, which provides an average gain of 10 months of life at the populational level; immunization against tetanus or poliomyelitis, an average gain of 3 months each; screening for detection of arterial hypertension, an average gain of 2 months; screening for detection of uterine cervical cancer, an average gain of 2 weeks of life. It must be emphasized that, in all these examples, the average gain in life provided by that particular intervention is estimated at a whole-population level, or in other words, if all of a population of children was vaccinated against tetanus, the average gain in life at a populational level would today be estimated as 3 months. Likewise, in the field of therapeutics it is estimated that the gains in life expectancy over the whole population
These facts may contribute towards situations in which individuals vaccinated with diphtheric toxoid or under- going serum therapy do not present full protection against infections caused by C. ulcerans. Even if it is considered that the diphtheric toxoid may have a protec- tive effect against diphtheria caused by C. ulcerans (i.e. through the presence of attenuated clinical symp- toms), it should be remembered that the vaccination only presents the action of DT and probably does not impede colonization by toxigenic corynebacteria. There is agreement among researchers that, in the absence of a proven vaccine against C. ulcerans, diphtheric toxoid remains a reasonable alternative, especially in cases of convalescence. On the other hand, it is also believed that there is a scarcity of evidence to show that vaccina- tion with diphtheric toxoid, even when kept up-to-date, would impede zoonotic diphtheria or other diseases caused by C. ulcerans. 94,107
Tetanus-diphtheria is another vaccine recommended for HCW. Only 54.7% residents were up-to-date for Td, but none had received Tdap. Of note, Td vaccine is offered free of charge in Brazil, but not the tetanus- diphtheria-acellular pertussis vaccine (Tdap). Different studies have shown an increase in cases of pertussis among adults and adolescents over the last 20 years 7,18 . This has been attributed to the waning immunity
mice. The L+/10/50 test dose was defined as the amount of tetanus toxin that, combined with 0.1 IU standard tetanus antitoxin (NIBSC), caused death of 18-20 g mice 96 h after injection. Anti-diphtheria antibody ti- ters were determined by mixing different dilutions of guinea pig serum samples with L+/10/50 doses of diphtheria toxin, incubat- ing for 45 min at 37ºC, and subcutaneously injecting them into 250-300 g guinea pigs. The L+/10/50 test dose was defined as the amount of diphtheria toxin that, combined with 0.1 IU standard diphtheria antitoxin (NIBSC), caused the death of 250-300 g guinea pigs 96 h after injection. The mice and guinea pigs were observed for 96 h and all deaths were recorded. Parallel control tests with L+/10/50 doses of toxins mixed with three dilutions of the standard antitox- ins (NIBSC) were also performed.
ABSTRACT: Objectives: Vaccines represent an important advancement for improving the general health of a population. The efective recording of vaccine data is a factor for the deinition of its supply chain. This study investigated vaccine data recording relatively to data collected from vaccination rooms and data obtained from a government-developed Internet platform. Methods: The monthly recorded total number of diphtheria and tetanus toxoids and pertussis vaccine (alone or in combination with the Haemophilus inluenzae type b conjugate vaccine) doses administered in a medium-sized city of the Southeast region of Brazil was collected for the period January/2006 through December/2010 from two sources: City level (directly from vaccination rooms, the study “gold standard”), and Federal level (from an Internet platform developed by the country government). Data from these sources were compared using descriptive statistics and the Percentage error. Results: The data values made available by the Internet platform difered from those obtained from the vaccination rooms, with a Percentage error relatively to the actual values in the range [-0.48; 0.39]. Concordant values were observed only in one among the sixty analyzed months (1.66%). Conclusions: A frequent and large diference between the number of diphtheria and tetanus toxoids and pertussis vaccine doses administered in the two levels was detected.
color test was performed to check for the presence of metachromatic granules; if pres- ent, the C. diphtheriae would appear as green or blue color, sometimes chestnut brown. The diphtheria bacilli were identified after biochemical tests for the detection of sugar fermentation, urea hydrolysis, nitrate reduc- tion, and the presence of catalase and oxi- dase. The first reading was performed at 24 h, when sugar fermentation was observed and the nitrate enzymatic test was carried out. The biochemical tests were incubated for 5 days because of the possibility of later fermentation of sugars.
Immunological heterogeneity has long been the major challenge in developing broadly ef- fective vaccines to protect humans and animals against bacterial and viral infections. En- terotoxigenic Escherichia coli (ETEC) strains, the leading bacterial cause of diarrhea in humans, express at least 23 immunologically different colonization factor antigens (CFAs) and two distinct enterotoxins [heat-labile toxin (LT) and heat-stable toxin type Ib (STa or hSTa)]. ETEC strains expressing any one or two CFAs and either toxin cause diarrhea, therefore vaccines inducing broad immunity against a majority of CFAs, if not all, and both toxins are expected to be effective against ETEC. In this study, we applied the multiepitope fusion antigen (MEFA) strategy to construct ETEC antigens and examined antigens for broad anti-CFA and antitoxin immunogenicity. CFA MEFA CFA/I/II/IV [CVI 2014, 21(2):243- 9], which carried epitopes of seven CFAs [CFA/I, CFA/II (CS1, CS2, CS3), CFA/IV (CS4, CS5, CS6)] expressed by the most prevalent and virulent ETEC strains, was genetically fused to LT-STa toxoid fusion monomer 3xSTa A14Q -dmLT or 3xSTa N12S -dmLT [IAI 2014,
This study was part of a phase IV, single center, open-label study to determine an appropriate age for an adolescent MenCC booster vaccination. Detailed information on the study design and participants has been described previously . Briefly, healthy 10-, 12- and 15-year-old children were recruited in October 2011 from the Utrecht metropolitan area, The Netherlands. Participants had been vaccinated nine years earlier with a single dose of the MenC-polysaccha- ride conjugated to tetanus toxoid vaccine (MenC-TT, NeisVac C TM , Baxter) at 14 months, 2.8 years and 5.8 years, respectively. In addition, all participants were vaccinated according to the Dutch NIP, which includes a tetanus vaccination (DTaP-IPV) at the age of 2, 3, 4 and 11 months and a booster dose (DT-IPV) at the age of 4 years and 9 years. Written informed con- sent was obtained from both parents and from participants aged 12 years. Ethical approval for the study was obtained from a local ethics committee (Verenigde Commissies Mensgebon- den Onderzoek). The study was registered at the Dutch Trial register (http://www.trialregister. nl; NTR3521).