Subcutaneous immunoglobulin replacement for treatment of humoral immune dysfunction in patients with chronic lymphocytic leukemia

Background

Patients with chronic lymphocytic leukemia (CLL) experience hypogammaglobinemia and non-neutropenic infections. In this exploratory proof of concept study, our objective was to determine the prevalence of humoral immunodeficiency in patients with CLL and serum IgG ≥ 400 mg/dL, and to evaluate the efficacy of subcutaneous immunoglobulin (SCIG) in this population.

Patients and methods

Patients with CLL with serum IgG ≥ 400 mg/dL were evaluated for serum IgG, IgM, IgA, along with pre/post vaccine IgG titers to diphtheria, tetanus, and Streptococcus pneumoniae. Patients with evidence of humoral dysfunction were treated with SCIG with Hizentra every 7±2 days for 24 weeks.

Results

Fifteen patients enrolled with median IgG = 782 mg/dL [IQR: 570 to 827], and 6/15 (40%) responded to vaccination with Td, while 5/15 (33%) responded to vaccination with PPV23. 14/15 (93.3%) demonstrated humoral immunodeficiency as evidenced by suboptimal vaccine responses, and were treated with SCIG. In patients treated with SCIG, serum IgG increased from 670 mg/dL [IQR: 565 to 819] to 1054 mg/dL [IQR: 1040 to 1166] after 24 weeks (95% CI: 271–540). For streptococcus pneumoniae, the median protective serotypes at baseline was 8 [IQR: 4 to 9] and increased to 17 [IQR: 17 to 19] after 24 weeks (95% CI: 6.93–13.72). Non-neutropenic infections (NNI) decreased from 14 to 5 during treatment with SCIG.

Conclusions

Patients with CLL demonstrate humoral immunodeficiency despite IgG > 400 mg/dL. For these patients, SCIG is well tolerated and efficacious in improving serum IgG, specific IgG to streptococcus pneumoniae, and may decrease reliance on antibiotics for the treatment of NNIs.

Clinical trials registration

NCT 03730129.

[Diphtheria: a 'forgotten' disease?]

Respiratory diphtheria is an acute respiratory tract infection. The high mortality rates (5-10%) are related to airway obstruction and local and systemic effects of the diphtheria toxin. Vaccination against diphtheria has been available through the Dutch national vaccination programme since the 1950s. The disease has now become rare as a result of herd immunity by these vaccinations. As a consequence, the disease has largely been forgotten, which can result in it not being recognised and treated in time. In addition, diphtheria antitoxin is not always available. In this article, we are drawing attention to the need for immunisation. We also look back at how diphtheria prevention started in the Netherlands.

Persistence of bactericidal antibodies 4 years after a booster dose of quadrivalent meningococcal diphtheria toxoid conjugate vaccine (MenACWY-D)

One dose of quadrivalent meningococcal conjugate vaccine (MenACWY) was first recommended for US adolescents (ages 11-12 years) in 2005 to protect against invasive meningococcal disease (IMD). In 2010, after evidence emerged about waning protection within 5 years after MenACWY vaccination, the US Advisory Committee on Immunization Practices (ACIP) recommended a MenACWY booster at age 16 years. We used a serum bactericidal assay with human complement (hSBA) to evaluate antibody persistence after a MenACWY-D booster in a sample of 110 participants who received the booster 4 years earlier in a phase 2 study. High proportions (89.9-98.2%) of participants maintained hSBA titers (≥1:4) associated with protection against IMD; a majority (81.7-97.2%) also had hSBA titers ≥1:8, a more conservative threshold. These findings support ACIP recommendations regarding MenACWY booster vaccination, which are aimed at protecting adolescents and young adults throughout the period in which they are at increased risk of IMD.

Safety and Immunogenicity of Two Doses of a Quadrivalent Meningococcal Polysaccharide Diphtheria Toxoid Conjugate Vaccine in Indian and Russian Children Aged 9 to 17 Months

OBJECTIVE

Evaluation of tolerability, safety and immunogenicity of a two-dose series of a quadrivalent meningococcal polysaccharide diptheria toxoid conjugate (ACYW-D) vaccine in Indian and Russian infants/toddlers.

DESIGN

Open-label, single-arm, phase III multi-national trial.

STUDY PARTICIPANTS

300 children aged 9-17 months, previously unvaccinated against meningococcal disease from four sites each in India (n=200) and the Russian Federation (n=100).

INTERVENTION

Two 0.5 mL doses of ACYW-D by intramuscular injection, 3-6 months apart.

MAIN OUTCOME MEASURES

Meningococcal antibody titers to serogroups A, C, W-135 and Y, determined using a serum bactericidal assay in the presence of human complement before vaccination and 28 days after the second vaccination. Titers ≥1:8 against either/all of the A, C, W-135 or Y were considered sero-protective.

RESULTS

After dose 2, 95.7-99.5% and 92.9-99.0% of infants/toddlers achieved seroprotection across the four serogroups in India and the Russian Federation, respectively. No immediate adverse events were reported after any dose of ACYW-D. Solicited reactions were reported in 49.2% of participants, and were mainly of Grade 1 severity, and resolved within three days. Unsolicited adverse events were reported in 19.1% of infants: one event (Grade 3 diarrhea, resolving within one day) was considered related to study vaccine. No non-serious adverse events led to premature withdrawal from the study. Four serious adverse events were reported; none were considered related to study vaccine. No deaths occurred during the study.

CONCLUSIONS

A two-dose series of ACYW-D vaccine in Indian and Russian children (9-17 month) was well-tolerated with no safety concerns, and induced robust bactericidal antibody responses against the meningococcal serogroups contained in the vaccine.

Reactogenicity and immunogenicity of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) in pregnant and nonpregnant women

OBJECTIVE

Tetanus toxoid, reduced diphtheria toxoid, and acellular pertusiss (Tdap) vaccine is recommended during each pregnancy, regardless of prior receipt. Data on reactogenicity and immunogenicity, particularly after repeated Tdap, are limited. We compared local injection-site and systemic reactions and serologic response following Tdap in (1) pregnant and nonpregnant women and (2) pregnant women by self-reported prior Tdap receipt.

STUDY DESIGN

Pregnant women (gestational age 20-34 weeks) and nonpregnant women receiving Tdap were enrolled in this observational study. Injection-site and systemic reactions were assessed for one week post-vaccination. Pertussis toxin, filamentous hemagglutinin, pertactin, fimbriae, tetanus and diphtheria specific IgG antibody titers were determined by standardized enzyme-linked immunosorbent assay at baseline and 28 days post-vaccination. Reactogenicity and serologic responses were compared by pregnancy status, and within pregnant women by self-reported prior Tdap receipt.

RESULTS

374 pregnant and 225 nonpregnant women were vaccinated. Severe local or systemic reactions or "any" fever were uncommon (≤3% for both groups). Moderate/severe injection-site pain was significantly higher in pregnant (17.9%) versus nonpregnant (11.1%) women, but did not prompt a healthcare visit. Proportions of other moderate/severe or any severe reactions were not significantly higher in pregnant compared to nonpregnant women. Moderate/severe (including pain) and severe reactions were not significantly higher in pregnant women receiving repeat versus first-time Tdap. Antibody titers increased from baseline to post-vaccination for all vaccine antigens in pregnant and nonpregnant women; post-vaccination titers against pertussis toxin and filamentous hemagglutinin were significantly higher in nonpregnant versus pregnant women (p < 0.01).

CONCLUSION

Tdap was well-tolerated in pregnant and nonpregnant women. Pregnant women were more likely to report moderate/severe pain at the Tdap injection-site compared with nonpregnant women, but did not necessitate medical visits. Prior Tdap receipt did not increase occurrence of moderate/severe local or systemic reactions in pregnant women. Serologic responses to all vaccine antigens were robust. Clinical Trial Registration@ClinicalTrials.gov. NCT02209623. https://clinicaltrials.gov/ct2/show/NCT02209623.

Coated and Hollow Microneedle-Mediated Intradermal Immunization in Mice with Diphtheria Toxoid Loaded Mesoporous Silica Nanoparticles

PURPOSE

To examine the immunogenicity of diphtheria toxoid (DT) loaded mesoporous silica nanoparticles (MSNs) after coated and hollow microneedle-mediated intradermal immunization in mice.

METHODS

DT was loaded into MSNs and the nanoparticle surface was coated with a lipid bilayer (LB-MSN-DT). To prepare coated microneedles, alternating layers of negatively charged LB-MSN-DT and positively charged N-trimethyl chitosan (TMC) were coated onto pH-sensitive microneedle arrays via a layer-by-layer approach. Microneedle arrays coated with 5 or 3 layers of LB-MSN-DT were used to immunize mice and the elicited antibody responses were compared with those induced by hollow microneedle-injected liquid formulation of LB-MSN-DT. Liquid DT formulation with and without TMC (DT/TMC) injected by a hollow microneedle were used as controls.

RESULTS

LB-MSN-DT had an average size of about 670 nm and a zeta potential of -35 mV. The encapsulation efficiency of DT in the nanoparticles was 77%. The amount of nano-encapsulated DT coated onto the microneedle array increased linearly with increasing number of the coating layers. Nano-encapsulated DT induced stronger immune responses than DT solution when delivered intradermally via hollow microneedles, but not when delivered via coated microneedles.

CONCLUSION

Both the nano-encapsulation of DT and the type of microneedles affect the immunogenicity of the antigen.

Adult Diphtheria Vaccination

Low adult vaccination coverage in Indonesia may contribute to a recent outbreak of diphtheria in Indonesia. Although well known as a pediatric vaccine, diphtheria vaccination should be administered as booster to adolescence and adults for longer prevention. Adult vaccine differs from pediatric vaccine but have similar protection. Additionally, there is special recommendation to vaccinate pregnant women and elderly people aged 65 years or more.

Postbooster Antibodies from Humans as Source of Diphtheria Antitoxin

Diphtheria antitoxin for therapeutic use is in limited supply. A potential source might be affinity-purified antibodies originally derived from plasma of adults who received a booster dose of a vaccine containing diphtheria toxoid. These antibodies might be useful for treating even severe cases of diphtheria.

Vaccines to combat the opioid crisis: Vaccines that prevent opioids and other substances of abuse from entering the brain could effectively treat addiction and abuse

Novel vaccines against substances of abuse generate a strong antibody response that prevents the drug from entering the brain. These could become a safe and efficient tool to combat a growing crisis of opioid abuse.

Serum Vaccine Antibody Concentrations in Adolescents Exposed to Perfluorinated Compounds

BACKGROUND

Postnatal exposure to perfluorinated alkylate substances (PFASs) is associated with lower serum concentrations of specific antibodies against certain childhood vaccines at 7 y.

OBJECTIVES

We prospectively followed a Faroese birth cohort to determine these associations at 13 y.

METHODS

In 516 subjects (79% of eligible cohort members) who were 13 years old, serum concentrations of PFASs and of antibodies against diphtheria and tetanus were measured and were compared with data from the previous examination at 7 y. Multiple regression analyses and structural equation models were applied to determine the association between postnatal PFAS exposures and antibody concentrations.

RESULTS

Serum concentrations of PFASs and antibodies generally declined from 7 y to 13 y. However, 68 subjects had visited the emergency room and had likely received a vaccination booster, and a total of 202 children showed higher vaccine antibody concentrations at 13 y than at 7 y. Therefore, separate analyses were conducted after exclusion of these two subgroups. Diphtheria antibody concentrations decreased at elevated PFAS concentrations at 13 y and 7 y; the associations were statistically significant for perfluorodecanoate (PFDA) at 7 y and for perfluorooctanoate (PFOA) at 13 y, both suggesting a decrease by ∼25% for each doubling of exposure. Structural equation models showed that a doubling in PFAS exposure at 7 y was associated with losses in diphtheria antibody concentrations at 13 y of 10–30% for the five PFASs. Few associations were observed for anti-tetanus concentrations.

CONCLUSIONS

These results are in accord with previous findings of PFAS immunotoxicity at current exposure levels. https://doi.org/10.1289/EHP275.

Immunogenicity and efficacy of a rationally designed vaccine against vascular endothelial growth factor in mouse solid tumor models

Vascular endothelial growth factor (VEGF) plays an important role in the progression of various cancers. The VEGF-specific antibody bevacizumab combined with chemotherapy was shown to significantly improve progression-free survival in certain cancers. However, repeated administration is necessary for effective suppression of VEGF, thereby making the therapy expensive and cumbersome. Thus, it is urgent to develop alternative reagents such as VEGF vaccines. Here we report that DTT-VEGF, a VEGF-based antigen consisting of the receptor-binding domain of VEGF and diphtheria toxin T domain (DTT), not only stimulated neutralizing antibody response, but also induced type 1 immune response as well as anti-tumor cytotoxic T lymphocytes in mice when administered with aluminum hydroxide adjuvant. The antibodies triggered by DTT-VEGF immunization inhibited the binding of VEGF to VEGF receptor and downregulated the serum VEGF levels in tumor-bearing mice. VEGF-specific IgG2a and IgG2b antibodies as well as type 1 cytokines were stimulated by DTT-VEGF vaccination. The splenocytes from DTT-VEGF-immunized mice showed cytotoxic activity against B16-F10 cells expressing VEGF. Extensive necrosis with severe hemorrhage and enhanced CD8+ T cell infiltration were observed in tumors from DTT-VEGF-immunized mice. The percentages of CD31+ vascular areas in the tumor sections from DTT-VEGF-immunized mice were significantly lower than those of control mice. DTT-VEGF significantly inhibited tumor growth in preventive and therapeutic vaccination settings in mouse models. Our data suggest that DTT is an effective antigen carrier to break immune self-tolerance and our vaccine design has potential to be used for human cancer therapy.

Does vaccination ensure protection? Assessing diphtheria and tetanus antibody levels in a population of healthy children: A cross-sectional study

Vaccination effectiveness is proven when the disease does not develop after a patient is exposed to the pathogen. In the case of rare diseases, vaccination effectiveness is assessed by monitoring specific antibody levels in the population. Such recurrent analyses allow the evaluation of vaccination programs. The primary schedule of diphtheria and tetanus vaccinations is similar in various countries, with differences mainly in the number and timing of booster doses. The aim of the study was to assess diphtheria and tetanus antibody concentrations in a population of healthy children.Diphtheria and tetanus antibody levels were analyzed in a group of 324 children aged 18 to 180 months. All children were vaccinated in accordance with the Polish vaccination schedule.Specific antibody concentrations greater than 0.1 IU/mL were considered protective against tetanus or diphtheria. Levels above 1.0 were considered to ensure long-term protection.Protective levels of diphtheria antibodies were found in 229 patients (70.46%), and of tetanus in 306 patients (94.15%). Statistically significant differences were found in tetanus antibody levels in different age groups. Mean concentrations and the percentage of children with high tetanus antibody titers increased with age. No similar correlation was found for diphtheria antibodies. High diphtheria antibody levels co-occurred in 72% of the children with high tetanus antibody levels; 95% of the children with low tetanus antibody levels had low levels of diphtheria antibodies.The percentage of children with protective diphtheria antibody levels is lower than that in the case of tetanus antibodies, both in Poland and abroad, but the high proportion of children without diphtheria protection in Poland is an exception. This is all the more puzzling when taking into account that Polish children are administered a total of 5 doses containing a high concentration of diphtheria toxoid, at intervals shorter than 5 years. The decrease in antibody titers occurring over time is a significant factor in vaccination program planning.Tetanus antibody concentrations were found to be high, but responses to the diphtheria and tetanus components were divergent. The percentage of children protected against diphtheria was significantly lower than protected against tetanus.

Immunogenicity of MenACWY-CRM in Korean Military Recruits: Influence of Tetanus-Diphtheria Toxoid Vaccination on the Vaccine Response to MenACWY-CRM

The quadrivalent meningococcal conjugate vaccine (MenACWY-CRM) has been introduced for military recruits in Korea since 2012. This study was performed to evaluate the immunogenicity of MenACWY-CRM in Korean military recruits. In addition, the influence of tetanus-diphtheria toxoids (Td) vaccination on the vaccine response to MenACWY-CRM was analyzed. A total of 75 military recruits were enrolled. Among them, 18 received a dose of MenACWY-CRM only (group 1), and 57 received Td three days before MenACWY-CRM immunization (group 2). The immunogenicity of MenACWY-CRM was compared between the two groups. The serum bactericidal activity with baby rabbit complement was measured before and three weeks after immunization against serogroups A, C, W-135, and Y. The geometric mean titers (GMTs) against four serogroups were significantly increased in both groups after immunization. Compared to group 2, group 1 exhibited significantly higher vaccine responses in several aspects: post-immune GMTs against serogroup A and C, seroresponse rates against serogroup A, and a fold increases of titers against serogroup A, C, and Y. MenACWY-CRM was immunogenic against all vaccine-serogroups in Korean military recruits. Vaccine response to MenACWY-CRM was influenced by Td administered three days earlier.

IMMUNOGENICITY AND SAFETY OF QUINVAXEM® (DIPHTHERIA, TETANUS, WHOLE-CELL PERTUSSIS, HEPATITIS B AND HAEMOPHILUS INFLUENZAE TYPE B VACCINE) GIVEN TO VIETNAMESE INFANTS AT 2 TO 4 MONTHS OF AGE

Vietnam plans to replace the routine childhood diphtheria, pertussis and tetanus combination (DPT) vaccine with a pentavalent vaccine. The present study was performed to assess the immunogenicity and safety of the combined diphtheria, tetanus, whole-cell pertussis, hepatitis B (HepB), and Haemophilus influenzae type b (Hib) (DTwP-HepB-Hib) Quinvaxem® vaccine in children. A total of 131 infants received the Quinvaxem® vaccine at 2, 3 and 4 months. Antibody levels were measured at baseline, at one month after the third injection and one year after the first injection. Seroprotection rates were high for each vaccine antigen at one month after the third dose: 93.1% for diphtheria, 98.5% for tetanus, 99.2% for pertussis (seroconversion rate), 93.1% for HepB, and 100% for Hib (anti-PRP ≥ 0.15 µg/ml). The rate of children with protective antibodies persisting at one year after the first dose was 88.4% for diphtheria, 49.6% for pertussis, 82.2% for tetanus, 76.7% for HepB and 97.7% for Hib (anti-PRP ≥ 0.15 µg/ml). The Quinvaxem® vaccine was well tolerated and has a low rate of adverse events. Quinvaxem® given at 2, 3 and 4 months of age was immunogenic and safe for primary immunization among infants in Vietnam.

Diphtheria in Lao PDR: Insufficient Coverage or Ineffective Vaccine?

Background

During late 2012 and early 2013 several outbreaks of diphthe-ria were notified in the North of the Lao People’s Democratic Republic. The aim of this study was to determine whether the re-emergence of this vaccine-preventable disease was due to insufficient vaccination coverage or reduction of vaccine effectiveness within the affected regions.

Methods

A serosurvey was conducted in the Huaphan Province on a cluster sampling of 132 children aged 12–59 months. Serum samples, socio-demographic data, nutri-tional status and vaccination history were collected when available. Anti-diphtheria and anti-tetanus IgG antibody levels were measured by ELISA.

Results

Overall, 63.6% of participants had detectable diphtheria antibodies and 71.2% tetanus antibodies. Factors independently associated with non-vaccination against diphtheria were the distance from the health centre (OR: 6.35 [95% CI: 1.4–28.8], p = 0.01), the Lao Theung ethnicity (OR: 12.2 [95% CI:1,74–85, 4], p = 0.01) and the lack of advice on vac-cination given at birth (OR: 9.8 [95% CI: 1.5–63.8], (p = 0.01) while the level of maternal edu-cation was a protective factor (OR: 0.08 [95% CI: 0.008–0.81], p = 0.03). Most respondents claimed financial difficulties as the main reason for non-vaccination. Out of 55 children whose vaccination certificates stated that they were given all 3 doses of diphtheria-containing vaccine, 83.6% had diphtheria antibodies and 92.7% had tetanus antibodies. Furthermore, despite a high prevalence of stunted and underweight children (53% and 25.8%, respectively), the low levels of anti-diphtheria antibodies were not correlated to the nutritional status.

Conclusions

Our data highlight a significant deficit in both the vaccination coverage and diphtheria vaccine effectiveness within the Huaphan Province. Technical defi-ciencies in the methods of storage and distribution of vaccines as well as unreliability of vac-cination cards are discussed. Several hypotheses are advanced to explain such a decline in immunity against diphtheria and recommendations are provided to prevent future outbreaks.

Differential activation of CD57-defined natural killer cell subsets during recall responses to vaccine antigens

Natural killer (NK) cells contribute to the effector phase of vaccine-induced adaptive immune responses, secreting cytokines and releasing cytotoxic granules. The proportion of responding NK cells varies between individuals and by vaccine, suggesting that functionally discrete subsets of NK cells with different activation requirements may be involved. Here, we have used responses to individual components of the DTP vaccine [tetanus toxoid (TT), diphtheria toxoid (DT), whole cell inactivated pertussis] to characterize the NK cell subsets involved in interleukin-2-dependent recall responses. Culture with TT, DT or pertussis induced NK cell CD25 expression and interferon-γ production in previously vaccinated individuals. Responses were the most robust against whole cell pertussis, with responses to TT being particularly low. Functional analysis of discrete NK cell subsets revealed that transition from CD56bright to CD56dim correlated with increased responsiveness to CD16 cross-linking, whereas increasing CD57 expression correlated with a loss of responsiveness to cytokines. A higher frequency of CD56dim CD57− NK cells expressed CD25 and interferon-γ following stimulation with vaccine antigen compared with CD56dim CD57+ NK cells and made the largest overall contribution to this response. CD56dim CD57int NK cells represent an intermediate functional phenotype in response to vaccine-induced and receptor-mediated stimuli. These findings have implications for the ability of NK cells to contribute to the effector response after vaccination and for vaccine-induced immunity in older individuals.

A palindromic CpG-containing phosphodiester oligodeoxynucleotide as a mucosal adjuvant stimulates plasmacytoid dendritic cell-mediated T(H)1 immunity

BACKGROUND

CpG oligodeoxynucleotides (ODNs), resembling bacterial DNA, are currently tested in clinical trials as vaccine adjuvants. They have the nuclease-resistant phosphorothioate bond; the immune responses elicited differ according to the CpG ODN sequence and vaccination method. To develop a CpG ODN that can induce plasmacytoid dendritic cell (pDC)-mediated T(H)1 immunity through the mucosa, we constructed phosphodiester G9.1 comprising one palindromic CpG motif with unique polyguanosine-runs that allows degradation similar to naturally occurring bacterial DNA.

METHODS

T(H)1 and T(H)2 immunity activation was evaluated by cytokine production pattern and T-bet/GATA-3 ratio in human peripheral blood mononuclear cells and mouse bone marrow cells. Adjuvanticity was evaluated in mice administered G9.1 with diphtheria toxoid (DT) through nasal vaccination.

RESULTS

G9.1 exhibited stronger IFN-α-inducing activity than A-class CpG ODN2216 and increased T-bet/GATA-3 ratio by enhancing T-bet expression. Nasally administered G9.1 plus DT induced DT-specific mucosal IgA and serum IgG, but not IgE, responses with antitoxin activity in C57BL/6 and BALB/c mice, possibly due to IFN/BAFF production. Induction of T(H)1, but not T(H)2-type Abs depended completely on pDCs, the first in vivo demonstration by CpG ODNs.

CONCLUSIONS

G9.1 is a promising mucosal adjuvant for induction of pDC-mediated T(H)1 immunity.

[Persistant perfluorinated compounds cause immunotoxic effects]

Perfluorinated compounds are highly stable and useful industrial chemicals. Both perfluorooctane sulfonic acid and perfluorooctanoic acid cause immunotoxic effects in animal models at serum concentrations similar to human levels. In children who have undergone routine vaccinations, serum concentrations of these substances are inversely associated with concentrations of antibodies against diphtheria and tetanus. Prevention of such effects will require a decrease of exposure limits by at least 100-fold. Immunotoxicity is not included in routine testing of industrial chemicals but urgently needs attention.

Seroprevalence of diphtheria toxoid IgG antibodies in children, adolescents and adults in Poland

BACKGROUND

Recommendations for diphtheria immunization are to apply an effective primary immunization in infancy and to maintain immunity throughout life. Immunity against diphtheria depends primarily on antibody to the diphtheria toxin. This study evaluated the seroprevalence of IgG diphtheria antitoxin in sera of healthy children, adolescents and adults in Poland.

METHODS

A total of 1387 serum samples collected between 2010 and 2012 from individuals with ages ranging from 1 month to 85 years were investigated. Antibody concentrations were measured with an enzyme-linked immunosorbent assay (Anti-Diphtheria Toxoid ELISA IgG, Euroimmun, Germany).

RESULTS

The results showed that among 1387 individuals examined, 547 (39.4%) had anti-diphtheria toxoid IgG antibody levels below 0.1 IU/ml (36.9% ≤ 18 years and 40.5% >18 years old, respectively). The 212 (50.8%) children and 542 (55.9%) adults showed only basic protection (0.1-1.0 IU/ml) and need immediate booster. High levels of anti-diphtheria toxoid IgG antibodies (>1.0 IU/ml) were found more often in children and adolescent (12.2%) than in adults (3.6%) and this was statistically significant (P < 0.05). The proportion of seronegatives (< 0.1 IU/ml) in children below 2 years old, adolescents and young adults to 25 years old decreased from 53.5% to 17.4%. However, in older individuals the seronegative proportion tended to increase with age, from 22.7% in adults (26-30 years old) to 67.1% in subjects > 60 years old. Characteristically, in individuals > 40 years old high levels of anti-diphtheria toxoid IgG antibodies (>1.0 IU/ml) were not seen. There were no statistically significant differences in results in relation to gender.

CONCLUSIONS

The present study showed inadequate immunity levels to diphtheria amongst the Polish population, especially in adults > 40 years old and children ≤ 2 years old. To prevent reemergence of diphtheria an information campaign reminding people about recommendations concerning diphtheria booster vaccination in adults should be conducted. Moreover, the immunogenicity of the DTP vaccine used in Poland should be verified.

Serum vaccine antibody concentrations in children exposed to perfluorinated compounds

CONTEXT

Perfluorinated compounds (PFCs) have emerged as important food contaminants. They cause immune suppression in a rodent model at serum concentrations similar to those occurring in the US population, but adverse health effects of PFC exposure are poorly understood.

OBJECTIVE

To determine whether PFC exposure is associated with antibody response to childhood vaccinations.

DESIGN, SETTING, AND PARTICIPANTS

Prospective study of a birth cohort from the National Hospital in the Faroe Islands. A total of 656 consecutive singleton births were recruited during 1997-2000, [corrected] and 587 participated in follow-up through 2008.

MAIN OUTCOME MEASURES

Serum antibody concentrations against tetanus and diphtheria toxoids at ages 5 and 7 years.

RESULTS

Similar to results of prior studies in the United States, the PFCs with the highest serum concentrations were perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). Among PFCs in maternal pregnancy serum, PFOS showed the strongest negative correlations with antibody concentrations at age 5 years, for which a 2-fold greater concentration of exposure was associated with a difference of -39% (95% CI, -55% to -17%) in the diphtheria antibody concentration. PFCs in the child's serum at age 5 years showed uniformly negative associations with antibody levels, especially at age 7 years, except that the tetanus antibody level following PFOS exposure was not statistically significant. In a structural equation model, a 2-fold greater concentration of major PFCs in child serum was associated with a difference of -49% (95% CI, -67% to -23%) in the overall antibody concentration. A 2-fold increase in PFOS and PFOA concentrations at age 5 years was associated with odds ratios between 2.38 (95% CI, 0.89 to 6.35) and 4.20 (95% CI, 1.54 to 11.44) for falling below a clinically protective level of 0.1 IU/mL for tetanus and diphtheria antibodies at age 7 years.

CONCLUSION

Elevated exposures to PFCs were associated with reduced humoral immune response to routine childhood immunizations in children aged 5 and 7 years.

Measurement of antibodies to pneumococcal, meningococcal and haemophilus polysaccharides, and tetanus and diphtheria toxoids using a 19-plexed assay

The measurement of antibody responses to vaccination is useful in the assessment of immune status in suspected immune deficiency. Previous reliance on enzyme-linked immunoabsorbent assays (ELISA) has been cumbersome, time-consuming and expensive. The availability of flow cytometry systems has led to the development of multiplexed assays enabling simultaneous measurement of antibodies to several antigens. We optimized a flow cytometric bead-based assay to measure IgG and IgM concentrations in serum to 19 antigens contained in groups of bacterial subunit vaccines: pneumococcal vaccines, meningococcal vaccines, Haemophilus influenzae b (Hib), and tetanus and diphtheria toxoid vaccines. 89-SF was employed as the standard serum. The assay was used to determine specific antibody levels in serum from 193 healthy adult donors. IgG and pneumococcal IgM antibody concentrations were measurable across 3 log10 ranges encompassing the threshold protective IgG antibody levels for each antigen. There was little interference between antibody measurements by the 19-plexed assay compared with monoplexed assays, and a lack of cross-reactive IgG antibody, but evidence for cross-reacting IgM antibody for 3/19 pneumococcal antigens. 90th centile values for 15/19 IgG concentrations and 12/12 IgM concentrations of the 193 adult sera were within these ranges and percentages of sera containing protective IgG antibody levels varied from 4% to 95% depending on antigen. This multiplexed assay can simultaneously measure antibody levels to 19 bacterial vaccine antigens. It is suitable for use in standard clinical practice to assess the in vivo immune response to test vaccinations and measure absolute antibody levels to these antigens.

Immunogenicity and safety of combined adsorbed low-dose diphtheria, tetanus and inactivated poliovirus vaccine (REVAXIS (®)) versus combined diphtheria, tetanus and inactivated poliovirus vaccine (DT Polio (®)) given as a booster dose at 6 years of age

This randomized, comparative, phase-IIIb study conducted in France aimed to demonstrate whether seroprotection against diphtheria, tetanus and poliomyelitis 1 month after a single dose of REVAXIS (low-dose diphtheria) is non-inferior to seroprotection 1 month after a single dose of DT Polio (standard-dose diphtheria), both vaccines being given as a second booster to healthy children at 6 years of age. Children were randomly assigned to receive a single intramuscular dose of REVAXIS or DT Polio. Primary endpoints were the 1-month post-booster seroprotection rates for diphtheria, tetanus and poliovirus type-1, -2 and -3 antigens. Secondary endpoints were immunogenicity and safety observations. Of 788 children screened, 760 were randomized: REVAXIS group, 384 children; DT Polio group, 376 children. No relevant difference in demographic characteristics at baseline was observed between REVAXIS and DT Polio groups. Non-inferiority of REVAXIS compared with DT Polio for seroprotection was demonstrated against diphtheria (respectively 98.6% and 99.3%), tetanus (respectively 99.6% and 100%), and poliovirus antigens (100% for each types in both groups). No allergic reactions to REVAXIS were reported. A benefit/risk ratio in favor of REVAXIS was suggested by the trend towards a better tolerability of REVAXIS compared with DT Polio regarding the rate of severe solicited injection-site reactions. The results support the use of REVAXIS as a booster at 6 years of age in infants who previously received a three-dose primary series within the first 6 months of life and a first booster including diphtheria, tetanus and poliovirus vaccine(s) given before 2 years of age.

An alternative method for purifying and detoxifying diphtheria toxin

Infections caused by Corynebacterium diphtheriae frequently induce situations in which very small doses of antigens injected intradermally can cause strong inflammatory reactions. This bacterium secretes the diphtheria toxin (DT), a virulence factor that can be lethal to the human organism at doses below 0.1 μg/kg of body weight. The present work proposes alternative methods of DT purification using affinity chromatography and of DT detoxification through conjugating with the polymer methoxypolyethylene glycol activated (mPEG). Tests were performed to evaluate: the formation of edemas and the presence of dermonecrotic activity, in vitro cytotoxicity to Vero cells, the neutralizing activity of serum from guinea pigs immunized with the diphtheria toxoid inactivated with mPEG, and the immunogenic activity of the purified and modified toxin. The results indicated that purification with Blue Sepharose was an efficient method, yielding antigen purity equivalent to 2600 Lf/mg of protein nitrogen. The modification of the Purified Toxin with mPEG did not result in the formation of edema or necrosis although it was immunogenic and stimulated the formation of antibodies that could neutralize the Purified Toxin. The toxoid obtained from the purified toxin maintained its immunogenic characteristics, inducing antibodies with neutralizing activity; edema and necrosis were still observed, however.

A cohort study of developmental polychlorinated biphenyl (PCB) exposure in relation to post-vaccination antibody response at 6-months of age

BACKGROUND

Extensive experimental data in animals indicate that exposure to polychlorinated biphenyls (PCBs) during pregnancy leads to changes in offspring immune function during the postnatal period. Whether developmental PCB exposure influences immunologic development in humans has received little study.

METHODS

The study population was 384 mother-infant pairs recruited from two districts of eastern Slovakia for whom prospectively collected maternal, cord, and 6-month infant blood specimens were available. Several PCB congeners were measured in maternal, cord, and 6-month infant sera by high-resolution gas chromatography with electron capture detection. Concentrations of IgG-specific anti-haemophilus influenzae type b, tetanus toxoid, and diphtheria toxoid were assayed in 6-month infant sera using ELISA methods. Multiple linear regression was used to estimate the relation between maternal, cord, and 6-month infant PCB concentrations and the antibody concentrations evaluated at 6-months of age.

RESULTS

Overall, there was little evidence of an association between infant antibody concentrations and PCB measures during the pre- and early postnatal period. In addition, our results did not show specificity in terms of associations limited to a particular developmental period (e.g. pre- vs. postnatal), a particular antibody, or a particular PCB congener.

CONCLUSIONS

At the PCB concentrations measured in this cohort, which are high relative to most human populations today, we did not detect an association between maternal or early postnatal PCB exposure and specific antibody responses at 6-months of age.

Transcutaneous immunization studies in mice using diphtheria toxoid-loaded vesicle formulations and a microneedle array

Purpose

To determine the immunogenicity of diphtheria toxoid (DT) formulated in two types of vesicles following transcutaneous immunization (TCI) of mice onto microneedle array-treated skin.

Methods

DT-containing cationic liposomes or anionic surfactant-based vesicles were prepared by extrusion and sonication. The physicochemical properties were characterized in terms of size, ζ-potential, vesicle elasticity and antigen association. TCI was performed by applying formulations onto intact or microneedle array-pretreated mice skin, using cholera toxin as an adjuvant. Subcutaneous and intradermal immunizations were as control. Immune responses were evaluated by IgG and neutralizing antibody titers, and the immune-stimulatory properties were assessed using cultured dendritic cells.

Results

Stable DT-containing cationic liposomes (∼150 nm) and anionic vesicles (∼100 nm) were obtained. Incorporation of Span 80 increased liposome elasticity. About 90% and 77% DT was associated with liposomes and vesicles, respectively. TCI of all formulations resulted in substantial antibody titers only if microneedle pretreatment was applied. Co-administration of cholera toxin further augmented the immune responses of TCI. However, vesicle formulations didn’t enhance the immunogenicity on either intact or microneedle-treated skin and showed low stimulatory activity on dendritic cells.

Conclusions

Microneedle pretreatment and cholera toxin, but not antigen association to vesicles, enhances the immunogenicity of topically applied DT.

[Toxin-neutralizing properties of antibodies to diphtheria toxin recombinant subunits A and B and a new method of their estimation]

Development of complications during diphtheria depends to a large extent on toxin-neutralizing antibodies level in the patient's blood. Active immunization of people with diphtheria anatoxin is widely used for diphtheria prevention and passive immunization with hyperimmune antitoxic horse serum is used for diphtheria treatment. A traditional component of anti-diphtheria vaccines--diphtheria anatoxin has a number of serious disadvantages, which are mainly associated with complicated procedure of its production. Thus, the search for new antigen substances, which can effectively stimulate protective humoral response to diphtheria toxin, is an urgent task in anti-diphtheria vaccine development. Furthermore, one of the most important objects is the development of new in vitro methods for estimation of diphtheria toxin-neutralizing polyclonal and monoclonal antibodies, which allow to avoid using active diphtheria toxin and toxin-sensitive laboratory animals. Comparative studies of toxin-neutralizing antibodies induction after immunization of laboratory animals with recombinant subunits A and B of diphtheria toxin were carried out. The new method for detection of protective antibodies in serum was proposed. This method is based on the ToBI test (Toxin Binding Inhibition test); namely on the property of anti-diphtheria antibodies to inhibit the biding of toxin subunit B fused with enhanced green fluorescent protein (EGFP) to the sensitive to diphtheria toxin Vero cells. The ability of subunit B to induce toxin-neutralizing antibodies in laboratory animals (rabbits and guinea pigs) was confirmed by the intradermal test, which is traditionally used to detect protective antitoxic antibodies in the serum, and by flow cytometry method, developed for this purpose. The results suggest that diphtheria toxin recombinant subunit B may be used for the induction of the protective immune response. The new developed approach for estimation diphtheria toxin-neutralizing antibodies is more ethical and safe and can substitute successfully the traditional methods.

Immune modulation by adjuvants combined with diphtheria toxoid administered topically in BALB/c mice after microneedle array pretreatment

Purpose

In this study, modulation of the immune response against diphtheria toxoid (DT) by various adjuvants in transcutaneous immunization (TCI) with microneedle array pretreatment was investigated.

Methods

TCI was performed on BALB/c mice with or without microneedle array pretreatment using DT as a model antigen co-administrated with lipopolysaccharide (LPS), Quil A, CpG oligo deoxynucleotide (CpG) or cholera toxin (CT) as adjuvant. The immunogenicity was evaluated by measuring serum IgG subtype titers and neutralizing antibody titers.

Results

TCI with microneedle array pretreatment resulted in a 1,000-fold increase of DT-specific serum IgG levels as compared to TCI. The immune response was further improved by co-administration of adjuvants, showing a progressive increase in serum IgG titers when adjuvanted with LPS, Quil A, CpG and CT. IgG titers of the CT-adjuvanted group reached levels comparable to those obtained after DT-alum subcutaneous injection. The IgG1/IgG2a ratio of DT-specific antibodies decreased in the following sequence: plain DT, Quil A, CT and CpG, suggesting that the immune response was skewed towards the Th1 direction.

Conclusions

The potency and the quality of the immune response against DT administered by microneedle array mediated TCI can be modulated by co-administration of adjuvants.

Efficacy of diphtheria and tetanus vaccination in Gaza, Palestine

This study evaluated the effectiveness and usefulness of vaccination against diphtheria and tetanus in different age groups in Gaza, Palestine. Blood samples were collected from 180 children aged <12 years, 90 males and 90 females. Using ELISA methods, the efficacy of vaccination was estimated at 87.8% for diphtheria and 98.3% for tetanus. Mean serum titres varied significantly by age group: for diphtheria 0.24 IU/mL at age 2-4 years, 0.63 IU/mL at 7-8 years and 0.46 IU/mL at 11-12 years, and for tetanus 1.01 IU/mL, 2.63 IU/mL and 1.20 IU/mL respectively. The relatively low antibody titres, especially for diphtheria, suggest the need for a booster dose.

The novel arthritis-drug substance MCS-18 attenuates the antibody production in vivo

Influence of the novel arthritis drug-substance MCS-18 on the antibody (Ab) production against tetanus toxoid (TT) and diphtheria toxoid (DT) antigens was tested in vivo. Possible involvement of MCS-18 in Toll-like receptor (TLR) signalling pathway was further considered.

MATERIALS AND METHODS

Immunization of male CD1 mice was done with subcutaneous injection of TT emulsified in Freund's Complete (FCA) or Incomplete Adjuvant (FIA) and mixed diversly with MCS-18 and different test substances. To investigate the influence of TLR activation Pam3Cys and lipopolysaccharide (LPS) emulsified in FIA were tested in combinations with MCS-18. Antibody production was analysed in vivo by tetanus- or diphtheria-toxin neutralization test.

RESULTS

Immunogenicity of TT was significantly enhanced if administered together with FCA or TLR agonists Pam3Cys or LPS emulsified in FIA. It was shown that MCS-18 attenuated strongly the production of anti-TT Ab if administered together with the Ab elicitor FCA or TLR agonists in various combinations. MCS-18 was also active via oral administration.

DISCUSSION

These findings suggest that MCS-18 could be a potent, non-toxic antagonist or a down-regulator of TLR signalling pathway. Investigations on further models are needed to establish ifMCS-18 may influence particularly the production of RA-specific auto-antibodies, too.

Investigation of immunity level against diphtheria and reinforcement of immunity by booster vaccination for infection control staff in Okayama prefecture

The prevalence of immunity against diphtheria among Okayama local government staff members involved in diphtheria infection control was measured. Diphtheria booster vaccination was administered to staff members with low antitoxin levels (<0.1 IU/ml) in order to reinforce of immunity. Ninety-one (36.7%) of 248 staff members, 20-69 years of age, had fully protective antitoxin levels (> or =0.1 IU/ml), and the remaining 157 (63.3%) showed levels of <0.1 IU/ml. The rate of full protection was higher in females (44.9%) than in males (22.8%) and was also higher in the diphtheria-pertussis mixed vaccine (born in 1958-1967) and diphtheria-pertussis-tetanus mixed vaccine (born in 1968-) (58.3-61.0%) groups than in diphtheria vaccine (born in 1948-1957) and non-vaccinated (born until 1947) (7.4-18.9%) groups. Though antitoxin levels of 13 (68.4%) out of 19 staff members given booster vaccinations increased to 0.1 IU/ml, 50% of these individuals then showed levels of <0.1 IU/ml after 3 years. Most of the staff members with antitoxin levels of > or =0.1 IU/ml in the non-booster vaccination group maintained their immunity levels for 2-4 years, independent of their history of vaccination. To ensure that staff members of the local government have fully protective antitoxin levels against diphtheria, periodical confirmation of antitoxin levels and booster vaccination should both be systematically carried out.

Quality control of routine, experimental and real-time aged diphtheria toxoids by in vitro analytical techniques

Physicochemical and immunochemical techniques can be used to assess the quality of diphtheria toxoid vaccines. In a previous paper [Metz B, Jiskoot W, Hennink WE, Crommelin DJA, Kersten GFA. Physicochemical and immunochemical techniques predict the quality of diphtheria toxoid vaccines. Vaccine 2003;22(2):156-67], techniques were introduced which indicated toxoid quality with respect to safety and potency: SDS-PAGE, primary amino group determination, fluorescence/denaturation, circular dichroism and biosensor analyses. These analyses were performed with experimental toxoids from one toxin batch. In the present study, the quality of regular vaccine batches of different manufacturers, the properties of real-time aged products and a number of experimental toxoids were investigated, using the above-mentioned analytical techniques. We had the unique opportunity to analyse toxoids that were up to 40 years old. The real-time aged diphtheria toxoids showed hardly any structural differences as compared to the recently prepared products in both the analytical chemical techniques and the conventional potency and safety tests. The analytical assays discriminated between regular diphtheria toxoids and experimental toxoids prepared by methylation, acetylation or glutaraldehyde treatment. The analytical data showed a clear correlation with potency and safety of these toxoids. Based on the results, we refined the described physicochemical and immunochemical criteria that a standard diphtheria toxoid has to meet. We recommend further validation of these techniques for quality control of diphtheria toxoid vaccine because of their high precision and easy performance as compared to conventional in vivo procedures.

No influence of atopic diseases on antibody titres following tetanus, diphtheria and hepatitis B immunisation among adults

Several studies have reported associations between reduced humoral immune response to vaccine antigens and diseases with modified reactions of the immune system. We have investigated the influence of atopic diseases on specific IgG levels to tetanus, diphtheria and hepatitis B (HB), following immunisation, in a general adult population. From the Study of Health in Pomerania, a total number of 3,920 subjects aged 20 to 79 years were included in the analyses. Information on immunisation history, as well as behavioural and socio-demographic characteristics were collected. Anti-tetanus IgG, anti-diphtheria IgG and anti-HBs IgG were measured by indirect enzyme-linked immunosorbent assay (ELISA). Odds ratios and 95% confidence intervals were calculated using logistic regression. Atopic diseases were reported by 14% of participants. Proportions of 67%, 34% and 10% had been vaccinated against tetanus, diphtheria and hepatitis B within the past ten years, respectively. Multi-variable analyses revealed no associations between the presence of atopic diseases and all of the three vaccine-specific antibody titres. We conclude that there is no reduced immune response related to antibody production following immunisations against tetanus, diphtheria and hepatitis B in adults with atopic diseases.

[Study of diphtheria anatoxins in immunochemical and tissue culture assays]

Equine diphtheria antitoxins from different manufacturers were studied. Their immunochemical interaction with diphtheria toxin, toxoid, and antigens of Corynebacterium diphtheriae in ELISA and immunoblotting assays as well as biological activity in CHO cell assay were compared. The discovered differences between antitoxin samples with stated equal activity in IU/ml point to heterogeneity of antigen composition in preparations used for immunization. Mentioned methods allow to standardize antitoxins basing on their biological activity and immunochemical characteristics.

[The humoral immunity against diphtheria]

Results of the conducted study showed that naturally acquired antibacterial and postvaccinal antitoxic antibodies against diphtheria were found in human blood sera. Challenge of ADT-M toxoid to adults resulted in production of antitoxic as well as antibacterial antibodies in high concentrations. In response to challenge of ADT-M toxoid simultaneously with bacterial vaccine against diphtheria Codivac both antibacterial and antitoxic antibodies were synthesized in blood on optimal physiologic levels. This study revealed dynamics of some specific characteristics of humoral immune response after challenge of two different vaccines against diphtheria--ADT-M toxoid and Codivac vaccine.

Diphtheria toxoid-containing microparticulate powder formulations for pulmonary vaccination: preparation, characterization and evaluation in guinea pigs

In this study, the potential of N-Trimethyl chitosan (TMC, degree of quaternization 50%) and dextran microparticles for pulmonary delivery of diphtheria toxoid (DT) was investigated. The antigen-containing microparticles were prepared by drying of an aqueous solution of polymer and DT through a supercritical fluid (SCF) spraying process. The median volume diameter of the dry particles, as determined by laser diffraction analysis, was between 2 and 3 microm and the fine particle mass fractions smaller than 5 microm, as determined by cascade impactor analysis, were 35 and 56% for the dextran and TMC formulations, respectively. The water content of the particles as measured by Karl-Fischer titration was 2-3% (w/w). Pulmonary immunization with DT-TMC microparticles containing 2 or 10 Lf of DT resulted in a strong immunological response as reflected by the induction of IgM, IgG, IgG subclasses (IgG1 and IgG2) antibodies as well as neutralizing antibody titers comparable to or significantly higher than those achieved after subcutaneous (SC) administration of alum-adsorbed DT (2 Lf). Moreover, the IgG2/IgG1 ratio after pulmonary immunization with DT-TMC microparticles was substantially higher as compared to SC administered alum-adsorbed DT. In contrast, pulmonarily administered DT-dextran particles were poorly immunogenic. Among the tested formulations only pulmonarily administered DT-containing TMC microparticles induced detectable pulmonary secretory IgA levels. In conclusion, in this paper it is demonstrated that TMC microparticles are a potent new delivery system for pulmonary administered DT antigen.

Revaccination of Children after Completion of Standard Chemotherapy for Acute Leukemia

BACKGROUND

After the treatment of patients with acute leukemia, there is a decrease in vaccine-specific antibody and an increased susceptibility to certain vaccine-preventable diseases. A simple revaccination schedule is warranted.

METHOD

Fifty-nine children (age, 1-18 years) who had completed standard chemotherapy in accordance with Medical Research Council of United Kingdom protocols were recruited. All children received a single dose of Haemophilus influenzae type b (Hib), tetanus, diphtheria, acellular pertussis, meningococcus C, polio, measles, mumps, and rubella vaccines > or = 6 months after completion of treatment. Antibody concentrations were measured before vaccination and 2-4 weeks and 12 months after vaccination.

RESULTS

Prevaccination antibody levels were protective for all patients for tetanus (geometric mean concentration [GMC], 0.13 IU/mL; 95% CI, 0.1-0.17 IU/mL), for 87% for Hib (GMC, 0.5 microg/mL; 95% CI, 0.37-0.74 microg/mL), for 71% for measles (GMC, 301 mIU/mL; 95% CI, 163-557 mIU/mL), for 12% for meningococcus C (geometric mean titer [GMT], 1:2.9; 95% CI, 1:2.2 to 1:3.9), and for 11% for all 3 poliovirus serotypes. Revaccination resulted in a significant increase in levels of antibody to each vaccine antigen, with 100% of patients achieving optimal antitetanus antibody concentrations (defined as > 0.1 IU/mL; 1.5 IU/mL; 95% CI, 1.1-2.1 IU/mL), 93% achieving optimal antibody concentrations to Hib (defined as > 1.0 microg/mL; 6.5 microg/mL; 95% CI, 5.1-8.2 microg/mL), 94% achieving optimal antibody concentrations to measles (defined as > or = 120 mIU/mL; 2720 mIU/mL; 95% CI, 1423-5198 mIU/mL), 96% achieving optimal antibody concentrations to meningococcus C (defined as > or = 1:8; 1:1000; 95% CI, 1:483-1:2064), and 85% achieving optimal antibody concentrations to all the 3 poliovirus serotypes (defined as > or = 1:8). For the majority of subjects, protection persisted for at least 12 months after vaccination.

CONCLUSION

Revaccination of children after standard chemotherapy is important, and protection can be achieved in the majority of these children using a simple schedule of 1 vaccine dose at 6 months after completion of leukemia therapy.

Comparison of the safety and immunogenicity of concomitant and sequential administration of an adult formulation tetanus and diphtheria toxoids adsorbed combined with acellular pertussis (Tdap) vaccine and trivalent inactivated influenza vaccine in adults

The annual contact for influenza vaccination provides an opportunity to ensure that adults have received other recommended vaccines such as Tdap. Healthy 19-64 year-olds were randomized to receive concomitant administration of Tdap and influenza vaccines or influenza vaccine followed (in 4-6 weeks by) Tdap. 720 participants were enrolled. No clinically relevant between-group differences were observed in the rates or severities of erythema, swelling, or pain at the Tdap injection site. Injection-site pain was the most commonly reported adverse event (66.6% concomitant administration group versus 60.8% sequential administration group); most pain was graded as mild and resolved by day 3. Seroprotection and seroresponse rates for all influenza strains were comparable between the two groups. For diphtheria and tetanus, seroprotection rates and post-vaccination GMTs were non-inferior in the concomitant administration group compared to the sequential administration group. A trend for lower antibody responses to pertussis antigens PT, FHA, and FIM was observed after concomitant administration and, for PRN, this difference failed the non-inferiority criteria. While there is a small diminution in antibody response to tetanus and pertussis antigens, concomitant administration of Tdap and influenza vaccine was well tolerated and immunogenic and may offer practical advantages including convenience, compliance, and cost-savings.

[Transfer factor of immune reactivity to diphtheria-tetanus anatoxin modulates the action of neurotransmitters in the intestinal smooth muscle]

Transfer factor (TF) of immune reactivity (10(-5) - 10(-3) mg/ml) to diphtheria-tetanus anatoxin modulates slow waves and spontaneous contractile activity of non-atropinized smooth muscle stripes (SMS) of guinea-pig taenia coli. TF (10(-4) mg/ml) transforms slow waves into stable depolarization and tonic contraction. After SMS atropinization, the substance acts in the same way. In the presence of methylene blue (10(-5) M), a guanylatecyclase blocker, FT induces transitory increase of SMS muscle tone, which is followed by their stable relaxation. ATP and UTP, purinoceptors agonists, evoke substantial hyperpolarization of smooth muscle cells membrane and their relaxation. FT enhances post-inhibitory excitation in SMS. In the presence of acetylcholine (10(-5) M) FT (10(-4) mg/ml) transforms the inhibitory ATP action on tonic contraction into excitative. This substance (10(-5), 10(-4) mg/ml) enhances Ca2+ mobilization from ryanodine-sensitive calcium store, inhibits the release of these cations from IP3-sensitive calcium store of sarcoplasmic reticulum. TF demolishes the inhibitory actions of sodium nitroprusside (nitric oxide donor), and noradrenaline in taenia coli smooth muscles.

Are there altered antibody responses to measles, mumps, or rubella viruses in autism?

The role that virus infections play in autism is not known. Others have reported that antibodies against measles virus are higher in the sera/plasma of children with autism versus controls. The authors investigated antibody titers to measles, mumps, and rubella viruses and diphtheria toxoid in children with autism, both classic onset (33) and regressive onset (26) forms, controls (25, healthy age- and gender-matched) and individuals with Tourette's syndrome (24) via enzyme-linked immunosorbent assays. No significant differences in antibody titers to measles, mumps, and rubella viruses and diphtheria toxoid were found among the four groups. Additionally, there were no significant differences between the four groups for total immunoglobulin (Ig)G or IgM. Interestingly, the authors did find a significant number (15/59) of autism subjects (classic and regressive onset combined) who had a very low or no antibody titer against rubella virus, compared to a combine control/Tourette's group (2/49).

Toxoid flocculation assay by laser light-scattering

Internationally accepted designations of antigen content for toxoid vaccines are provided by the WHO in Lf (limes flocculationis) units, based on the formation of antigen-antibody complexes. The current assay method for Lf determination involves observation of the complexes by eye, making the development of a more objective system highly desirable. Here we report a novel detection system using a laser light-scattering platelet aggregometer. The system was highly reproducible and more objective than the current method. Only three sets of duplicate data were sufficient for statistically significant determination of toxoid Lf by parabolic regression.

Diphtheria boosters for adults: Balancing risks

Combined tetanus-diphtheria vaccines are now the only means of protecting adults from tetanus or diphtheria. When advising on the benefits and risk of vaccinating for one disease, clinicians now have to consider the other vaccine component, and questions have arisen about where the balance of risk lies for different patients. Five doses of diphtheria-toxoid containing vaccine are probably sufficient protection for individuals who remain in low-incidence countries such as those in most of Western Europe. Adults who remain in the UK are extremely unlikely to be exposed to diphtheria and this needs to be taken into account when assessing the balance of risk where individuals have received fewer than five doses of diphtheria toxoid but five or more doses of tetanus toxoid. In contrast to diphtheria, if someone has received fewer than five doses of tetanus toxoid but is up to date for diphtheria toxoid, the balance of lifelong risk is probably in favour of giving tetanus toxoid irrespective of the individual's diphtheria status. For travellers to diphtheria endemic countries boosters are recommended if more than 10 years has elapsed since the last dose. For individuals who have already received five or more doses of tetanus vaccine in the past, receiving further boosters of tetanus in combination with diphtheria toxoid is unlikely to cause any significant reactions. The only absolute contraindication to such boosters is a previously documented anaphylactic reaction to either diphtheria or tetanus toxoid. Individuals who have a history of such a reaction should be well advised regarding probable risk of infection, symptoms of the disease and the need to seek early treatment.

Prevalence and correlates of diphtheria toxoid antibodies in children and adults in Israel

A seroepidemiological study was performed to evaluate immunity to diphtheria and to determine the correlates of diphtheria toxoid antibody levels among children and adults in Israel. In total, 3,185 sera from an age-stratified sample of children and adults, obtained in 2000-2001, were tested for diphtheria toxoid antibodies by an in-house double-antigen ELISA. A level of <or=0.01 IU/mL (no immune protection or seronegativity) was found in 168 (5.3%) of the 3,185 subjects, 639 (20.1%) had antibody levels of 0.011-0.099 IU/mL (basic immunity or low seropositivity), and 2,378 (74.7%) had antibody levels >or=0.1 IU/mL (full protection or seropositivity). Seronegativity increased significantly in subjects aged >50 years, reaching levels of 9.7%, 12.6% and 18.9% in the groups aged 50-54, 55-59 and >60 years, respectively (p 0.001), with rates of basic immunity following a similar pattern. Subjects born abroad had higher seronegativity rates than those born in Israel (7.7% vs. 4.9%; p 0.019). No difference in diphtheria toxoid antibody levels was found according to other demographical variables, such as gender, Jewish or Arab ethnicity, urban or rural settlements, and the subjects' place of residence. The level of immunity to diphtheria among children and adults in Israel was satisfactory, with the exception of individuals aged >50 years. The risk of diphtheria outbreaks is low, but sporadic cases may occur among individuals lacking basic immunity against the disease.