Evaluation of INSTAND e.V.'s external proficiency testing program for tetanus and diphtheria antitoxin detection: Lessons for assessing levels of immunoprotection.

OBJECTIVES: The aim of this study was to evaluate the development and status quo of the quality of high throughput in vitro diagnostic testing for tetanus and diphtheria antitoxin antibody (ATX) concentrations based on external quality assessment (EQA) data. METHODS: We analyzed manufacturer-specific data of 22 EQA surveys-each for the detection of tetanus and diphtheria ATX-to check the diagnostic strength of the corresponding in vitro diagnostic systems. RESULTS: While the results were mostly well aligned, individual surveys showed widely dispersed ATX concentrations. The medians of manufacturer collectives deviated from the overall median by up to 8.9-fold in the case of diphtheria ATX and by up to 3.5-fold in the case of tetanus ATX. Such a distribution in the results is particularly critical in the cut-off range for immunity and may lead to an incorrect assessment of vaccination status. CONCLUSION: These results were surprising as there are International Standards for both ATX; however, the results may be linked to the high ATX concentration of the reference material, which deviates considerably from clinically significant concentrations. To increase the accuracy and diagnostic strength of both assays, we recommend a recalibration of the test systems and verification of their traceability to the International Standards.

Higher Tetanus Toxoid Immunity 2 Years After PsA-TT Introduction in Mali.

BACKGROUND: In 2010, mass vaccination with a then-new meningococcal A polysaccharide-tetanus toxoid protein conjugate vaccine (PsA-TT, or MenAfriVac) was undertaken in 1- to 29-year-olds in Bamako, Mali. Whether vaccination with PsA-TT effectively boosts tetanus immunity in a population with heterogeneous baseline tetanus immunity is not known. We assessed the impact of PsA-TT on tetanus toxoid (TT) immunity by quantifying age- and sex-specific immunity prior to and 2 years after introduction. METHODS: Using a household-based, age-stratified design, we randomly selected participants for a prevaccination serological survey in 2010 and a postvaccination survey in 2012. TT immunoglobulin G (IgG) antibodies were quantified and geometric mean concentrations (GMCs) pre- and postvaccination among all age groups targeted for vaccination were compared. The probability of TT IgG levels ≥0.1 IU/mL (indicating short-term protection) and ≥1.0 IU/mL (indicating long-term protection) by age and sex was determined using logistic regression models. RESULTS: Analysis of 793 prevaccination and 800 postvaccination sera indicated that while GMCs were low pre-PsA-TT, significantly higher GMCs in all age-sex strata were observed 2 years after PsA-TT introduction. The percentage with short-term immunity increased from 57.1% to 88.4% (31.3-point increase; 95% confidence interval [CI], 26.6-36.0;, P < .0001) and with long-term immunity increased from 20.0% to 58.5% (38.5-point increase; 95% CI, 33.7-43.3; P < .0001) pre- and postvaccination. CONCLUSIONS: Significantly higher TT immunity was observed among vaccine-targeted age groups up to 2 years after Mali's PsA-TT mass vaccination campaign. Our results, combined with evidence from clinical trials, strongly suggest that conjugate vaccines containing TT such as PsA-TT should be considered bivalent vaccines because of their ability to boost tetanus immunity.

Key protection factors against tetanus: Anti-tetanus toxin antibody affinity and its ability to prevent tetanus toxin - ganglioside interaction.

Antibodies capable to neutralize tetanus toxin (TeNT) are key factors in protection against tetanus disease. Although antibody-based therapeutics for treatment of tetanus exist on the market its production is tedious. Hence, the tetanus-specific antibodies preparation that could be easily produced in large scale in vitro would be beneficial. Monoclonal antibodies (MAbs) are considered for a long time as a reagent of choice, but the core drawback is how to select a MAb that would be safe in providing efficacious protection. In this study we have investigated the parameters crucial for a single MAb to be assigned as protective. Eight murine MAbs were characterized in vitro for their reactivity toward TeNT and assessed in vivo for protectiveness against TeNT intoxication. Correlation of in vitro and in vivo data has revealed that in vitro selection of MAb that is protective in vivo could be performed by a combination of two assays: the measurement of MAb affinity toward TeNT taking Ka 1 × 10(8) M(-1) as a threshold level, and the evaluation of its capability to prevent TeNT-ganglioside interaction. Single MAb could be taken into consideration as a potential therapeutic only if it has a capacity to completely inhibits TeNT-ganglioside complex formation.

Antitoxins for diphtheria and tetanus decline more slowly after vaccination with DTwP than with DTaP: a study in a Chinese population.

OBJECTIVES: DTP vaccines are used for the prevention of pertussis, diphtheria and tetanus. In 2007, in Gaobeidian city, China, the DTwP vaccine was replaced with DTaP. This study described the diphtheria and tetanus sero-epidemiology in subjects vaccinated solely with DTwP or DTaP. METHODS: Blood samples were obtained between October 2012 and June 2013 from 587 healthy subjects aged 2-17 years. Serum IgG antibodies against diphtheria and tetanus were determined using ELISA. Interrupted time series analyses examined the changes in antitoxin levels over time and analyzed the alterations in diphtheria and tetanus antitoxin levels after the vaccine switch. RESULTS: Mean concentrations of diphtheria antitoxin and tetanus antitoxin were 0.074 IU/ml (95% CI 0.065-0.084) and 0.063 IU/ml (95% CI 0.053-0.076). The protection rates (antitoxins >0.01 IU/ml) for diphtheria and tetanus were 88.25% and 82.11%. Mean antitoxin levels for both diphtheria and tetanus decreased with increasing age, but this decrease was much slower for DTwP than DTaP. CONCLUSIONS: Although the observed protection rates for diphtheria and tetanus were sufficient to prevent an outbreak at present, the means levels of diphtheria and tetanus antitoxins decreased with increasing age; therefore, booster vaccinations at 7 and 12 years of age would be strengthened in Gaobeidian city, China.

A case of tetanus infection in an adult with a protective tetanus antibody level.

Tetanus is a bacterial infection caused by Clostridium tetani and most commonly presents as trismus or other muscle spasms. Despite the development of the tetanus toxoid vaccine, tetanus infection has not been eradicated. Additionally, while there are hypothesized protective levels of tetanus antibody, tetanus infection may still occur in properly vaccinated individuals. We report the case of a 31-year-old male that presented to the emergency department (ED) with a 2-day history of neck and jaw pain. He reports puncturing his hand with a rusty nail 10 days prior. His reported vaccination history was that he received his last booster vaccination 13 years prior to presentation. In the ED, tetanus vaccine, tetanus immune globulin, and metronidazole were administered. His symptoms improved over the next 2 days and resolved at day 6. Despite his presentation of tetanus infection and rule out of other causes for his symptoms, his tetanus antibody level was reported at 8.4 U/mL, which is considered to be protective.A tetanus antibody level that is adequate for protective immunity should not preclude a patient from treatment of tetanus infection. This case demonstrates that a thorough history, physical exam, and rule out of other causes should guide treatment when there is concern for a tetanus infection.

Tetanus immunity in individuals aged 50 years or older in Kashan, Iran.

Tetanus can be only prevented by vaccination because immunity against this disease is rarely acquired, even by natural infections. To maintain long-term protective immunity against tetanus, booster immunization is essential for adolescents and adults. Most hospitalized cases and virtually all deaths occur in people over 60 years of age. The purpose of this study was to investigate the degree of protective tetanus immunity among 50 years of age and older people in Kashan city, Iran. This cross-sectional study carried out on 180 randomly individuals aged 50 years or older who were visiting a central laboratory for health examinations in 2008. Participants' serum levels of tetanus antitoxin were measured by enzyme linked immunosorbent assay. A standard questionnaire was used to collect demographic data and information about risk factors. The prevalence of protective tetanus immunity in various age groups was described and sociodemographic factors that potentially influenced the degree of tetanus immunity were analyzed. Overall, 180 persons were included. Of these, 72 (40%) had never received a toxoid booster, while 47 (26.1%) had received a booster at least once. Among all participants, 30 (16.7%) had protective tetanus antitoxin levels (≥ 0.11 IU/mL), and 34 (18.9%) had protective antitoxin levels without the need of an immediate booster ≥0.51 IU/mL. Among 86 participants aged >60 years, 6 (7%) had protective antitoxin levels ≥0.1-1 IU/mL, and 5(5.8%) had protective antitoxin levels ≥1 IU/mL. Male gender and prior receipt of toxoid booster(s) were associated with protective tetanus immunity. Tetanus antitoxin levels declined with age. It appears that most 50 years of age and older adults do not have protective levels of tetanus antitoxin because of inadequate vaccination coverage. There is a need to improve the immunity levels of this age group. It is recommended to vaccinate elderly people against tetanus.

Maternal immunization with tetanus-diphtheria-pertussis vaccine: effect on maternal and neonatal serum antibody levels.

OBJECTIVE: We sought to determine whether tetanus-diphtheria-pertussis vaccination (Tdap) in pregnancy provides newborns antibodies against pertussis when compared to mothers who did not receive Tdap. STUDY DESIGN: Paired maternal and umbilical cord blood samples were collected at the time of delivery and the serum stored at -86°C. For each paired sample of maternal and cord blood, the medical chart and vaccine history was reviewed to determine whether Tdap was received or not. RESULTS: Newborns born from mothers who received Tdap during pregnancy had significantly higher concentrations of diphtheria antitoxin (P < .001), tetanus antitoxin (P = .004), and antibodies to pertussis toxin (P < .001), filamentous hemagglutinin (P = .002), pertactin (P < .001), and fimbriae 2/3 (P < .001) when compared to newborns from mothers who did not receive Tdap. There was a significant increase in the odds that newborns from mothers who received Tdap during pregnancy have antibodies that may provide protection against diphtheria (P = .0141), pertussis toxin (P < .0001), and fimbriae 2/3 (P = .0146). CONCLUSION: Administering Tdap during pregnancy increases antibody titers against diphtheria and pertussis antigens. Maternal Tdap may prevent neonatal pertussis infection.

[Immunization of patients with chronic obstructive pulmonary disease with vaccines of Bubo-M and hepatitis B].

AIM: To assess tolerability and immunological activity of Bubo-M vaccine and hepatitis B vaccine in patients with chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: Sixty-three patients with moderate and severe COPD aged 35-65 years were immunized against diphtheria, tetanus, and hepatitis B. Bubo-M vaccine as well as vaccine against hepatitis B were used for immunization. Immunologic effect of vaccination was assessed by measurement of serum antibody level to HBsAg as well as to diphtheria and tetanus toxoids. Assessment of antibody level to HBsAg was performed by ELISA, and levels of antibodies to diphtheria and tetanus toxoids--by micromethod in direct hemagglutination assay. Reactogenicity of Bubo-M vaccine was measured according to duration and intensity of local and systemic reactions. RESULTS: The local and systemic reactions were infrequent, serious adverse events after vaccination were not observed. Six months after vaccination, protective antibody titers to hepatitis B, diphtheria and tetanus were determined in all immunized persons--either healthy, or with COPD. During completion of vaccination schedule, significant reduction of acute respiratory infections rate and main disease exacerbations was noted in patients with COPD. CONCLUSION: Good tolerability and high immunogenicity of Bubo-M and hepatitis B vaccines were demonstrated in both groups of vacinees. These vaccines could be recommended for booster vaccination of adults with COPD.

Comparison of five commercial anti-tetanus toxoid immunoglobulin G enzyme-linked immunosorbent assays.

Five commercially available enzyme-linked immunosorbent assays for the measurement of anti-tetanus toxoid immunoglobulin G (IgG) antibodies were evaluated for performance. The data suggest that there are manufacturer-dependent differences in sensitivity and accuracy for the determination of tetanus toxoid IgG antibodies that could result in different diagnostic interpretations.

Serological immunity to diphtheria and tetanus in healthy adults in Delhi, India.

Widespread childhood immunization with DPT (diphtheria, pertussis and tetanus) has largely eradicated diphtheria and tetanus from many countries. The reduction in the circulation of toxigenic strains has resulted in less natural boosting of adult immunity. As a result, the adult population in countries with high childhood immunization coverage have become susceptible to the disease. The duration of immunity after primary immunization to diphtheria and tetanus is limited and a reduction in immunity is common in adults. With this perspective, the present study was carried out on a random serum sample of 255 healthy individuals aged 20-50 years. The serum samples were tested for immunoglobulin G levels against diphtheria and tetanus by enzyme immuno assays. Fifty-three per cent of adults were unprotected; 22 % were seen to have only a basic protection against diphtheria; 25% were protected against both diseases; and 47% were susceptible to tetanus. The susceptibility was seen to increase with age. To avoid epidemics in the future, immunity must be improved. It is important to treat even the most trivial wound with care and tetanus toxoid immunization. Also, it is necessary to monitor the community for immunity to diphtheria using standard techniques in order to undertake epidemiological surveillances of, and prevention from, these dreadful diseases.

Decline of tetanus antitoxin level with age in taiwan.

BACKGROUND/PURPOSE: Tetanus is caused by Clostridium tetani, and is a vaccine-preventable infectious disease. The purpose of this study was to investigate the degree of protective tetanus immunity among adolescents and adults in Taiwan, which may provide valuable information for recommendations for tetanus vaccination strategy. METHODS: Individuals aged 16 years or older who were visiting a local hospital for health examinations were invited to participate in the study. Participants' serum levels of tetanus antitoxin were measured. A standard questionnaire was used to collect demographic data and information about risk factors. The prevalence of protective tetanus immunity in various age groups was described and sociodemographic factors that potentially influenced the degree of tetanus immunity were analyzed. RESULTS: Overall, 326 persons were included. Of these, 217 (67%) had never received a toxoid booster, while 109 (33%) had received a booster at least once. Among all participants, 95% had protective tetanus antitoxin levels (> or = 0.11 IU/mL), and 60% had protective antitoxin levels without the need of an immediate booster, i.e. > or = 0.51 IU/mL. Among 70 participants aged > 60 years, 89% had protective antitoxin levels > or = 0.11 IU/mL, and 31% had protective antitoxin levels > or = 0.51 IU/mL. Tetanus antitoxin levels declined with age. Male gender, birth after 1955, and prior receipt of toxoid booster(s) were independently associated with protective tetanus immunity (> or = 0.51 IU/mL) by multivariate analysis. Compared with those without tetanus toxoid boosters, individuals with a prior booster had higher antitoxin levels. The percentage of people with protective immunity declined if the interval between the last toxoid booster increased. CONCLUSION: Waning immunity to tetanus was observed after primary tetanus vaccination or toxoid booster. The public health policy that one dose of toxoid booster after primary vaccination should be emphasized for continuing protection against tetanus.

Vacunación antitetánica / No disponible

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Characterization of rotavirus specific B cells and their relation with serological memory.

We quantified circulating total, rotavirus (RV) and Tetanus toxin (TT) memory B cells (mBc) in healthy adults using a limiting dilution assay (LDA) and a flow cytometry assay (FCA) that permit evaluation of both CD27+ and CD27- mBc. RV mBc were enriched in the CD27-, IgG+ and in the CD27+, IgM+ subsets. The numbers of RV mBc were higher by FCA than by LDA and results of the two assays did not correlate. TT IgGmBc and RV IgA mBc determined by FCA and by LDA correlated with TT plasma IgG and RV plasma IgA, respectively. The mean ratio of specific mBc/mug/ml of the corresponding plasma immunoglobulin was lower for TT IgG than for RV IgA mBc. Our studies contribute to understand the relationship between circulating mBc and serological memory, and enhance our capacity to develop better correlates of protection against RV disease.

Bioneedles as vaccine carriers.

Bioneedles are small hollow mini implants fabricated from biodegradable polymers which can be filled with antigen. Bioneedles can be used for vaccination without syringes and needles. Formulations have been prepared containing tetanus toxoid with and without aluminum phosphate. Stability and immunogenicity of Bioneedles were compared with liquid formulations. The antigen, when formulated in Bioneedles, retained fully its antigenicity up to 60 degrees C for 1 week whereas the antigen, in its liquid form, lost all activity at 60 degrees C after 1 week. After 3 weeks at 60 degrees C, a recovery of 60% was still found in the Bioneedles. Mice injected with Bioneedles with adjuvanted tetanus toxoid showed a comparable functional antibody response to the group receiving conventional liquid injections. This response was achieved with a four times lower antigen concentration when using the Bioneedles compared to the regular injections. We conclude that Bioneedles are good alternatives for injections using needles and syringes.

Nasal immunization studies by cationic, fusogenic and cationic-fusogenic liposomes encapsulated with tetanus toxoid.

Particulate antigens are more effective than soluble antigens in induction of systemic and mucosal immunity; possibly because they are more efficiently endocytosed by mucosal-associated lymphoid tissue (MALT) M cells. In this study, we determined the systemic and mucosal immune responses in rabbits following intranasal immunization with tetanus toxoid (TT) entrapped in cationic, fusogenic and cationic-fusogenic liposomes. Liposomes containing TT were prepared by dehydration-rehydration method. The volume mean diameter of cationic, fusogenic and cationic-fusogenic liposomes were 3.4 +/- 0.6, 4.3 +/- 2.3 and 3.4 +/- 1.5 microm, respectively. Encapsulation efficiency of TT in cationic, fusogenic and cationic-fusogenic liposomes was respectively determined as 49.1 +/- 8.4%, 48.5 +/- 2.1% and 50.8 +/- 4.9%. After 3 months, the leaking of encapsulated TT from liposomes ranged between 2.02 - 5.46%. Immunoreactivities of encapsulated TT in all kinds of liposomes were completely preserved, as studied by Sodium Dodecyl Sulfate - Polyacrylamide Gel Electrophoresis (SDS-PAGE) and Enzyme-Linked Immunosorbent Assay (ELISA). The highest serum immunoglobulin G (IgG) and antitoxin titers were observed in groups immunized with solution formulation (P< 0.001). However, the highest mucosal secretory IgA (sIgA) titers were achieved by fusogenic liposomes (five times more titers compared with TT solution, and 15 times more titers compared with i.m. vaccine), followed by cationic-fusogenic liposomes. No hemolysis was occurred on incubation of liposomes and human erythrocytes. Also after nasal administration of plain liposomes to human volunteers, no local irritation was seen. This study suggests that intranasal administration of fusogenic and cationic-fusogenic liposomes encapsulated with vaccines could be an effective way for inducing mucosal immune responses.