Levels of diphtheria and tetanus specific IgG of Portuguese adult women, before and after vaccination with adult type Td. Duration of immunity following vaccination

Acquired hypogammaglobulinemia and pathogen-specific antibody depletion after solid organ transplantation in human immunodeficiency virus infection: A brief report

Hypogammaglobulinemia (HGG) frequently occurs in recipients after types of (SOT). The incidence and significance of HGG in HIV+ recipients of SOT are just being explored. We reported that 12% of the recipients in the SOT in multi-center HIV-TR (HIV-TR) Study developed moderate or severe HGG at 1 year. In LT recipients, this was associated with serious infections and death. We have now further characterized the decreased antibodies in HIV+ SOT recipients who developed HGG. We measured the levels of pathogen-specific antibodies and poly-specific self-reactive antibodies (PSA) in relation to total IgG levels from serial serum samples for 20 HIV+ SOT recipients who developed moderate to severe HGG following SOT. Serum antibody levels to measles, tetanus toxoid, and HIV-1 were determined by EIA. Levels of PSAs were determined by incubating control lymphocytes with patient serum, staining with anti-human IgG Fab-FITC, and analysis by flow cytometry. Levels of PSA were higher compared to healthy, HIV-uninfected controls at pre-transplant baseline and increased by weeks 12 and 26, but the changes were not significant. Likewise, anti-HIV antibody levels remained unchanged over time. In contrast, antibody levels against measles and tetanus were significantly reduced from baseline by week 12, and did not return to baseline, even after 2 years. For HIV patients who develop moderate to severe HGG after transplant, the reduction in IgG levels is associated with a significant decrease in pathogen-specific antibody titers, while PSA levels and anti-HIV antibodies are unchanged. This may contribute to infectious complications and other clinical endpoints.

Determinants of Tetanus Vaccination among Adult Immigrants: Findings from the Portuguese National Health Survey 2014

Vaccination is an effective strategy to prevent tetanus, and in Portugal this service is provided free of charge. Despite this, immigrants reported lower tetanus vaccination coverage than did Portuguese natives. The objective of this study was to identify sociodemographic, migration-related, and access-to-care factors associated with tetanus vaccination coverage among adult immigrants, using data from the Portuguese National Health Survey 2014. For the sample of 1277 immigrants aged ≥18 years, we estimated self-reported tetanus vaccination within the preceding 10 years and its determinants using complex samples logistic regression. The overall self-reported tetanus vaccination coverage was 79.5% (95% CI: 75.8-82.8). Age (adjusted odd ratio (aOR) per 1 year age increase = 0.97, 95% CI: 0.95-0.99), higher household income per adult (aOR = 0.42, 95% CI: 0.19-0.96), having Portuguese citizenship (aOR = 2.30, 95% CI: 1.25-4.24), having private health insurance (aOR = 1.99, 95% CI: 1.06-3.71), and contact with family/general physician in the last 12 months (aOR = 1.59, 95% CI: 1.01-2.51) were associated with self-reported tetanus vaccination coverage among adult immigrants. We also found significant disparities in coverage between regions of residence. This study identified several determinants associated with self-reported tetanus vaccination coverage among adult immigrants in Portugal. These findings may help policymakers to design specific interventions to increase tetanus vaccination coverage among this population.

Tetanus-diphtheria vaccination in adults: the long-term persistence of antibodies is not dependent on polyclonal B-cell activation and the defective response to diphtheria toxoid re-vaccination is associated to HLADRB1∗01

Cellular and humoral immune responses to tetanus-diphtheria vaccine (Td) were assessed in human leukocyte antigen (HLA)-typed Italian military personnel who received multiple concomitant vaccines. Td-specific antibodies and T-lymphocytes were measured in individuals with one (group-1) and more than one (group-2) Td boosters. A third group (group-3), who received several vaccines, but not Td, was studied to verify the hypothesis of the polyclonal B-cell activation as mechanism for antibody persistence. The antibody response to Td toxoids was higher in group-1, who showed lower baseline antibody levels, than in group-2 subjects. The antibody response to tetanus was higher than to diphtheria toxoid in both groups. No correlation between antibody and cellular response, and no interference in the response to Td by co-administration of different vaccines were observed. HLA-DRB1∗01 allele was detected at significant higher frequency in subjects unable to double the baseline anti-diphtheria antibody levels after the vaccination. Anti-tetanus and diphtheria antibodies half-lives were assessed and the long-lasting persistence above the threshold for protection (0.1 IU/ml) was estimated in over 65 and 20 years, respectively. No significant increase of anti-diphtheria antibodies was observed in consequence of polyclonal B-cell activation. This study emphasizes the duration of Td vaccination-induced seroprotection, suggesting that re-vaccination should probably be performed at intervals longer than 10 years. No reciprocal interference by concomitantly administered vaccines has been observed. HLA-DRB1∗01 allele was significantly associated with anti-diphtheria defective response. Finally, this study does not confirm that anti-diphtheria antibody levels are maintained by polyclonal B-cell activation. Clinical trial registry: The study was registered with NCT01807780.

[Adult immunisation: General points, hot topics and perspectives]

Vaccination in immunocompetent adult mainly concerns booster vaccination against diphtheria, tetanus, polio and pertussis. Some chronic diseases may also require the achievement of pneumococcal and influenza vaccines. In addition, from the age of 65, annual influenza vaccination as well as one dose of a live attenuated shingles vaccine between 64 and 75 years are recommended. Immunocompromised adults, due to the increased risk of serious infections responsible of significant morbidity and mortality, are particularly concerned by vaccination. Main issues in this population are the decreased immunogenicity and efficacy of vaccination and the risk of infection with live attenuated vaccines and. Depending on the type of immunosuppression, the recommended vaccines and vaccination schemes differ. Vaccination of healthy persons caring or residing with immunocompromised patients is an important point in the vaccine strategy. The current perspectives in vaccinology concern the development of vaccines against healthcare associated infections (Clostridium difficile and Staphylococcus aureus in particular), the strategy of vaccination during pregnancy to protect new-borns (respiratory syncytial virus, group B streptococcus) and the development of new adjuvants and new routes of immunization. With the overall decline in immunization coverage and increasing distrust of vaccination, the problem of vaccine hesitancy is also a hot topic. The reasons for doubt in the vaccine usefulness and the solutions to be applied are also crucial issues.

Booster vaccination against tetanus and diphtheria: insufficient protection against diphtheria in young and elderly adults

We have recently demonstrated that single shot vaccinations against tetanus and diphtheria do not lead to long-lasting immunity against diphtheria in elderly persons despite administration at 5 year intervals. In the present study we have immunized a group of young adults against tetanus and diphtheria to compare the pre- and 28 days post-vaccination immune responses in the young group with results of the same vaccination performed in an elderly group of a previous study. We also studied protection in both groups 5 years after vaccination. We compared antibody titers at all three time points and also analyzed the T cell responses in both age groups 5 years after vaccination. Before vaccination 9 % of the elderly persons were not protected against tetanus, and 48 % did not have protection against diphtheria. In the young group all participants were protected against tetanus, but 52 % were also unprotected against diphtheria before vaccination. 28 days after vaccination 100 % of all participants had protective antibody concentrations against tetanus and only a small percentage in each age group (<10 %) was unprotected against diphtheria. 5 years later, 100 % of both cohorts were still protected against tetanus, but 24 % of the young and 54 % of the elderly group were unprotected against diphtheria. Antibody concentrations against diphtheria measured by ELISA correlated well with their neutralizing capacity. T cell responses to tetanus and diphtheria did not differ between young and old persons. We conclude that booster vaccinations against tetanus and diphtheria according to present recommendations provide long-lasting protection only against tetanus, but not against diphtheria, independently of age. In elderly persons, the level of protection is even lower, probably due to intrinsic age-related changes within the immune system and/or insufficient vaccination earlier in life.

Decennial diphtheria-tetanus adult boosters: are they really necessary?

Available epidemiological data shows that an average number of 59 cases of tetanus per year are still reported in Italy. Most of cases (80.2%) occur in subjects > 64 years-old. Furthermore, the proportion of females among subjects ≥ 65 years-old is significantly higher than males (87.7% vs. 64.4%, p < 0.0001). Seroprevalence data show that the percentage of subjects with protective tetanus antibody levels (> 0.1 IU/ml) decreases with increasing age. Most people aged ≥ 65 years are unprotected. The antibody levels are higher in males than females (p < 0.001) in subjects > 25 years-old. Conversely, extensive childhood immunization and adequate boosting vaccination of adults led to the near-elimination of diphtheria in Western countries. The current Italian National Immunization Prevention Plan 2012- 2014 recommends the administration of a primary vaccine course in the first year of life and booster at the preschool age, in adolescents and in adults every 10 years. Nevertheless, the need for decennial booster doses is debated by some experts, who state that the best time to offer a single dose of vaccine against tetanus and diphtheria is the age of 50, since low levels of antibody titers are observed. Considering the availability of combined vaccines against diphtheria, tetanus and pertussis (DTaP or dTaP), and the increasing incidence of pertussis in infants, who are at highest risk of serious complications, in adolescents and in adults, some countries have introduced decennial dTaP in the adults immunization schedule. It is desirable that this recommendation is also introduced in the future Italian Immunization Prevention Plan. The present review overviews the epidemiological data and the immunization strategies against tetanus, diphtheria and pertussis in Italy, discussing the rationale not only of decennial dT booster but also of the dTaP booster.

Tetanus in Italy 2001-2010: a continuing threat in older adults

Despite being a completely preventable disease, tetanus cases continue to occur in Italy and notification and hospitalization rates have been reported to be higher with respect to European and other industrialized countries. We examined statutory notification, hospitalization, mortality and seroprevalence data to describe tetanus epidemiology in Italy from 2001 to 2010. A total of 594 tetanus cases were notified, with an average annual incidence of 1.0/1,000,000 population. Most cases were unvaccinated or incompletely vaccinated. Eighty percent of cases occurred in subjects aged >64 years and a higher proportion of females with respect to males were reported in this age group. The annual number of hospital admissions was 1.4-1.7 times greater than the number of notifications in the same year. The mean annual number of reported deaths was 21. Seroprevalence data show progressively higher susceptibility levels with increasing age. Over 50% of persons aged 45-64 years and over two thirds of subjects ≥65 years had tetanus antibody levels <0.01 IU/ml. Results show that tetanus is a continuing problem in Italy and, as in other countries, most cases occur in older adults, especially elderly women. The observed differences in notification and hospitalization rates suggest underreporting by physicians. In recent years, Italy has accounted for most cases reported annually in the European Union (EU) but different case definitions are used. In Italy, a confirmed case is one that meets the clinical case definition while the EU case definition classifies confirmed cases as those with laboratory confirmation of disease. The incidence of clinical tetanus in Italy is ten-fold higher than in other industrialized countries, like Australia and Canada, likely due to higher susceptibility levels in Italy. In view of the low prevalence of tetanus antibodies in adults ≥45 years, strategies to improve vaccine uptake in this population group need to be implemented.

Prevalence of susceptibility to tetanus and diphtheria in health care workers in Catalonia

A seroprevalence study of tetanus and diphtheria was carried out in a sample of 537 health care workers in Catalonia. The prevalence of protective antibodies against tetanus was 93.9% (95% confidence interval: 91.5-95.7). The prevalence of protective antibodies against diphtheria was 46.4% (95% confidence interval: 42.1-50.7). Tetanus protection should be improved in health care workers born before 1975. The immune status against diphtheria was poor, with less than half of people born before 1975 correctly immunized.

Technical and diagnostic performance of five commercial anti-diphtheria toxoid IgG enzyme-linked immunosorbent assay kits

The technical and diagnostic performances of five commercially available enzyme-linked immunosorbent assays for the measurement of anti-diphtheria toxoid IgG antibodies were evaluated. There was good agreement between the relative sensitivities of the five assays, but the relative specificity of one of the assays differed from that of the other four assays. Three of the five assays possessed recoveries of the international reference material NIBSC 00/496 within the range of 90% to 110% at antibody levels >0.1 IU/ml. The data suggest that there are manufacture-dependent differences in relative sensitivity, specificity, and accuracy for the determination of anti-diphtheria toxoid IgG antibodies that could result in different diagnostic interpretations.