Specific IgG Titers Research Articles

Anti-helicobacter pylori activities of shoya powder and essential oils of thymus vulgaris and eucalyptus globulus.

Background:Helicobacter pylori, an infective agent of more than 50% of the world population is prominent to be the main causative factor in the etiologies of chronic, active or type B gastritis, peptic and duodenal ulcer, gastric carcinoma, and mucosa-associated lymphoid tumors. A high prevalence of this bacterium in dental plaque is always reported. Pharmacological treatment of H. pylori infections includes administration of 3-fold therapeutic regimens which are typically used to suppress H. pylori activity. However, antibiotic resistance frequently develops as a consequence of such treatment. Thus, searching for alternative therapies for H. pylori infections is of special interest.Materials and Methods:In this study, anti H. pylori activities of a traditional antimicrobial drug so-called Shoya and also essential oils of Thymus vulgaris and Eucalyptus globulus were investigated using antimicrobial analysis and serological screening methods.Results:The agar dilution method results revealed the Shoya with the highest inhibitory effect against H. pylori. Also serological screening on tested mice showed a significant effect of this drug in lowering the sera amount of anti H. pylori specific IgA and IgG titers. Both of the essential oils showed different degrees of antibacterial effect against H. pylori.Conclusion:The obtained results showed the antibacterial effect of Shoya powder and Essential oils from Thymus vulgaris and Eucalyptus globulus and purposes new therapeutical alternatives to control the H. pylori infection. Additional studies and clinical trials are necessary to approve the use of these data in health care and pharmacopeia systems.

Relatively high serum vitamin D levels do not impair the antibody response to encapsulated bacteria

Vitamin D skews the immune system towards a more tolerogenic state. Therefore, a relatively high vitamin D status, i.e., within the normal physiological range, might result in a lower antibody response to infection and vaccination. We hypothesized, however, that vitamin D is primarily important in establishing immune homeostasis, implying that a relatively high vitamin D status would not hamper an adequate antibody response against pathogens. Our results show that the vitamin D status did not differ between responders and hypo-responders in patients infected with Streptococcus pneumoniae, as well as patients vaccinated against S. pneumoniae, Neisseria meningitidis type C (MenC), and/or Haemophilus influenzae type b (Hib). Furthermore, specific IgG titers were not associated with the vitamin D status in patients vaccinated against S. pneumoniae and MenC, while there was a weak inverse association in Hib-vaccinated patients. These data indicate that a relatively high vitamin D status does not seem to hamper an adequate antibody response upon infection or vaccination, suggesting that vitamin D, in this setting, is not immunosuppressive.

HIV-specific antibodies capable of ADCC are common in breastmilk and are associated with reduced risk of transmission in women with high viral loads.

There are limited data describing the functional characteristics of HIV-1 specific antibodies in breast milk (BM) and their role in breastfeeding transmission. The ability of BM antibodies to bind HIV-1 envelope, neutralize heterologous and autologous viruses and direct antibody-dependent cell cytotoxicity (ADCC) were analyzed in BM and plasma obtained soon after delivery from 10 non-transmitting and 9 transmitting women with high systemic viral loads and plasma neutralizing antibodies (NAbs). Because subtype A is the dominant subtype in this cohort, a subtype A envelope variant that was sensitive to plasma NAbs was used to assess the different antibody activities. We found that NAbs against the subtype A heterologous virus and/or the woman's autologous viruses were rare in IgG and IgA purified from breast milk supernatant (BMS) – only 4 of 19 women had any detectable NAb activity against either virus. Detected NAbs were of low potency (median IC50 value of 10 versus 647 for the corresponding plasma) and were not associated with infant infection (p = 0.58). The low NAb activity in BMS versus plasma was reflected in binding antibody levels: HIV-1 envelope specific IgG titers were 2.2 log10 lower (compared to 0.59 log10 lower for IgA) in BMS versus plasma. In contrast, antibodies capable of ADCC were common and could be detected in the BMS from all 19 women. BMS envelope-specific IgG titers were associated with both detection of IgG NAbs (p = 0.0001)and BMS ADCC activity (p = 0.014). Importantly, BMS ADCC capacity was inversely associated with infant infection risk (p = 0.039). Our findings indicate that BMS has low levels of envelope specific IgG and IgA with limited neutralizing activity. However, this small study of women with high plasma viral loads suggests that breastmilk ADCC activity is a correlate of transmission that may impact infant infection risk.

Seroprevalence of measles among children affected by national measles elimination program in Korea, 2010

BackgroundFollowing the implementation of national measles elimination plan in Korea, the elimination was declared in 2006. In order to sustain the elimination, high population immunity should be continuously monitored. To evaluate the current age-related susceptibility within the Korean population, we conducted the seroprevalence in children and adolescents who were affected by the national measles elimination plan. MethodsWe used residual serum specimens to measure measles specific IgG and geometric mean titer (GMT) in birth cohorts 2007–2008 and 1997–2003. Among birth cohorts, 2007–2008 cohorts were grouped to evaluate the timeliness of first dose of MMR, 1994–2003 cohorts were grouped to evaluate the effect of keep-up MMR2 campaign, and 1992–1993 cohorts were grouped to evaluate the effect of catch-up campaign in 2001. ResultsOverall, measles seropositivity rate was 86%. The highest seroprevalence of measles IgG was in birth cohorts 2007–2008. Measles seropositivity declined continuously in age groups. The birth cohorts 1994–1996 showed significantly lower levels of seropositivity and GMT than did the other birth cohorts. ConclusionDespite efforts to eliminate measles for the past 10 years in Korea, our study revealed specific birth cohorts remaining at risk for transmission. The adolescents born during 1994–1996 had the lowest measles seropositivity levels, and might represent a ‘pocket’ that has potential at increased risk for measles transmission. Further discussion for follow-up immunization should be placed for consideration in the near future.

Streptococcus suis serotype 9 bacterin immunogenicity and protective efficacy

Streptococcus suis diseases in pigs, most importantly meningitis, are worldwide responsible for major economic losses in the pig industry. About one fourth of invasive S. suis diseases are caused by S. suis serotype 9 strains in Europe. However, little is known about serotype 9 since most studies were performed with serotype 2. The objective of this study was to determine the immunogenicity and protective efficacy of a serotype 9 bacterin in piglets. Challenge was conducted with a reference serotype 9 strain, belonging to the same clonal complex but to a different sequence type as the bacterin strain. The bacterin induced protection against mortality but not morbidity. Eleven days post infection, 3 of 7 vaccinated survivors were not fully convalescent and had not eliminated the challenge strain from inner organs completely. In accordance with the clinical findings, the majority of piglets showed fibrinous–suppurative lesions in at least one inner organ or tissue. In contrast to the placebo group such lesions were not detected in one third of bacterin-vaccinated piglets. Determination of specific serum IgG titers revealed that the bacterin elicited seroconversion against muramidase-released protein and basic membrane lipoprotein. Furthermore, vaccination was associated with induction of opsonizing antibodies against the serotype 9 challenge strain. However, titers of opsonizing antibodies were rather low in comparison to those found in our previous serotype 2 vaccination trial. Piglets developed substantially higher titers of opsonizing antibodies after challenge. Opsonizing antibodies were absorbable with the serotype 9 challenge strain but not with an unencapsulated isogenic mutant of a serotype 2 strain indicating their specificity. The results indicate that a serotype 9 bacterin is less protective than a serotype 2 bacterin, most likely due to inducing only low titers of opsonizing antibodies. This might contribute to emergence of serotype 9 strains, in particular strains of this clonal complex, in Europe.

Humoral Immune Responses in a Human Case of Glanders

Within 2 months of acquiring glanders, a patient developed 8-, 16-, and 4-fold increases, respectively, in specific IgA, IgG, and IgM serological titers against Burkholderia mallei. Within 14 months of infection, the titers decreased to the baseline. Serum from this patient was also highly reactive against Burkholderia pseudomallei whole cells. Burkholderia mallei whole cells did not react with sera from patients with other diseases. Therefore, an assay using a B. mallei cellular diagnostic antigen may be useful for the serodiagnosis of glanders.

418 Frequency of Food Hypersensitivity Mediated by IGG in Patients Received in a Venezuelan Laboratory During 2011

BackgroundFoods could cause adverse reactions, which manifested with similar symptoms that could complicate the diagnosis, that is, gastrointestinal disease, rashes, edema, eczema, asthma, anaphylaxis, others; these reactions may be mediated or not by immunological processes. In the past years there were many research studies related with different types of immunological reactions, like for example those mediated by IgG, which are characterized with delayed and insidious manifestations. These reactions could appear in hours or days after ingestion of a particular food. The intake of “toxic food” can lead to immunological reactions, which includes the formation of immune complexes, able to increase the development of gastrointestinal, dermatological, neurological, muscular and respiratory disorders. The objective of this study was to evaluate the frequency of significant specific IgG titers against some foods in patients referred to Corpodiagnostica Laboratory, (Caracas, Venezuela, an ISO 9001:2008 certified laboratory) from January to August 2011.MethodsThere were a total of 148 patients referred for serum specific IgG evaluation against foods. We measured patient's specific IgG titers against 45 foods using a commercial direct ELISA method (Dr. Fooke Labs, Germany), which is designed for the detection and quantification of specific IgG.ResultsWe found detectable levels of specific IgG titers in highest frequency for: milk 69%, cheese 67%, egg 64%, gluten 54%, sugar cane 51%, followed by wheat meal, rye Meal, and other foods in smaller proportions. Moreover, in 46 patients with known clinical history, including gastrointestinal symptoms, respiratory symptoms, pervasive developmental disorder (PDD) and autism, we detected levels of specific IgG to a significant number of foods simultaneously.ConclusionsThe Specific serum IgG determination against foods could be a interesting tool to help the diagnosis of non type I Allergy reactions, and there are many published studies that have been established that the decrease or even disappearance of specific IgG titers against foods are related to the improvement of the initial clinical manifestations on some patients, but further investigations need to be performed to clearly understand the different mechanisms involved and to rule out false positive results for this test in patients without symptoms.

A Viral Vectored Prime-Boost Immunization Regime Targeting the Malaria Pfs25 Antigen Induces Transmission-Blocking Activity

The ookinete surface protein Pfs25 is a macrogamete-to-ookinete/ookinete stage antigen of Plasmodium falciparum, capable of exerting high-level anti-malarial transmission-blocking activity following immunization with recombinant protein-in-adjuvant formulations. Here, this antigen was expressed in recombinant chimpanzee adenovirus 63 (ChAd63), human adenovirus serotype 5 (AdHu5) and modified vaccinia virus Ankara (MVA) viral vectored vaccines. Two immunizations were administered to mice in a heterologous prime-boost regime. Immunization of mice with AdHu5 Pfs25 at week 0 and MVA Pfs25 at week 10 (Ad-MVA Pfs25) resulted in high anti-Pfs25 IgG titers, consisting of predominantly isotypes IgG1 and IgG2a. A single priming immunization with ChAd63 Pfs25 was as effective as AdHu5 Pfs25 with respect to ELISA titers at 8 weeks post-immunization. Sera from Ad-MVA Pfs25 immunized mice inhibited the transmission of P. falciparum to the mosquito both ex vivo and in vivo. In a standard membrane-feeding assay using NF54 strain P. falciparum, oocyst intensity in Anopheles stephensi mosquitoes was significantly reduced in an IgG concentration-dependent manner when compared to control feeds (96% reduction of intensity, 78% reduction in prevalence at a 1 in 5 dilution of sera). In addition, an in vivo transmission-blocking effect was also demonstrated by direct feeding of immunized mice infected with Pfs25DR3, a chimeric P. berghei line expressing Pfs25 in place of endogenous Pbs25. In this assay the density of Pfs25DR3 oocysts was significantly reduced when mosquitoes were fed on vaccinated as compared to control mice (67% reduction of intensity, 28% reduction in prevalence) and specific IgG titer correlated with efficacy. These data confirm the utility of the adenovirus-MVA vaccine platform for the induction of antibodies with transmission-blocking activity, and support the continued development of this alternative approach to transmission-blocking malaria subunit vaccines.

Anti-Gal Titers in Healthy Adults and Inflammatory Bowel Disease Patients

Introduction ALPHA-GAL is a glycoconjugate present on cell membranes of mammals and bacteria but not humans who display anti-Gal antibodies (AB) in high titers provoked by the commensal gut flora. In the present study, we sought to determine the longitudinal course of alpha-Gal specific AB titers of all isotypes over 8 weeks among healthy adult subjects. Furthermore, we hypothesized that inflammatory bowel disease (IBD) patients display increased anti-Gal titers. Materials and methods We drew serum from healthy probands ( n = 20) weekly for 8 weeks and obtained plasma samples of from patients suffering from Crohn's disease ( n = 20) and ulcerative colitis ( n = 20). We measured anti-Gal ABs of all isotypes and total immunoglobulin (Ig) content using an enzyme-linked immunosorbent assay technique. For statistical evaluation of the longitudinal titers, we calculated confidence intervals for the slopes of a random intercept model, comparing variances between and within the probands. For group comparisons, we performed paired student t-tests and Pearson correlations. Results Alpha-Gal specific IgG, IgM, IgD, and IgA titers remained unvaried within a narrow range upon longitudinal observation. Most probands did not display alpha-Gal specific IgE ABs. Crohn's disease patients showed highly increased alpha-Gal-specific IgA titers compared with control subjects ( P < .01). Conclusion Apart from IgE, alpha-Gal-specific ABs of all isotypes remained constant over longer time periods in healthy subjects. Thus, significant titer changes actually represent increased antigen exposure and a specific anti-alpha-Gal response. Crohn's disease patients display increased anti-Gal IgA titers compared with healthy controls, which reflects a chronically impaired mucosal gut barrier in this patient cohort.

Nanostructured SBA-15 silica as an adjuvant in immunizations with hepatitis B vaccine.

To evaluate the applicability of SBA-15 silica as an adjuvant in immunizations with purified particles of the viral protein HBsAg, the main component of hepatitis B vaccine, Butang®, produced by Instituto Butantan. BALB/c mice orally or subcutaneously received 0.5 μg of HBsAg adsorbed/encapsulated to SBA-15 or adsorbed to Al(OH)3. To assess the secondary immune response, a subcutaneous booster was administered 30 days after the first immunization. Individual serum and fecal samples of each group were periodically collected for specific antibody titration by ELISA. Analysis of secretory IgA showed that mice orally primed with HBsAg on SBA-15 had increased levels of specific antibodies in primary and secondary immune responses. Specific serum IgA and IgG titers in HBsAg:SBA-15-orally immunized mice reached higher levels after the booster, demonstrating the effectiveness of oral vaccination with the use of silica. All immunized groups showed higher IgG1 levels. Our results clearly indicate the promising use of SBA-15 as an adjuvant, especially in oral immunizations.

Modulation of the Humoral Response to Dermatophagoides pteronyssinus Allergens in BALB/c Mice by Extract Modification and Adjuvant Use

Background: Currently, several strategies are being used in order to improve the safety and efficacy of allergen-specific immunotherapy; these strategies include the use of modified hypoallergenic extracts as well as different adjuvants with immunomodulatory properties in combination with native or modified extracts. The objectives of this study were to investigate the humoral response generated in mice to modified Dermatophagoides pteronyssinus extracts in the presence or absence of two different adjuvants. Methods: BALB/c mice were inoculated either with native, depigmented or depigmented-polymerised D. pteronyssinus without adjuvants or combined with aluminium hydroxide or oligodeoxinucleotides containing CpG motifs. IgE concentration, specific total IgG, IgG1 and IgG2a titres were measured in mice sera and cross-reactivity inhibition experiments were performed. IgG antigenic profiles were obtained by immunoblotting for all formulations. Results: Inoculation of depigmented-polymerised extract induced statistically significant lower IgE levels than the native extract even when adsorbed onto aluminium hydroxide. When this extract was inoculated in the presence of oligodeoxinucleotides containing CpG motifs, it elicited high IgG levels, a high IgG2a/lgG1 ratio and low IgE production. Furthermore, the antigenic profiles observed after extract inoculation showed punctual differences between the depigmented-polymerised extract and the native or depigmented extracts. Conclusions: Our results suggest that the depigmentation and polymerisation process modifies the native extract’s antigenic and immunogenic properties and converts the depigmented-polymerised extract into a better choice for allergen-specific immunotherapy.

Antimicrobial and immunomodulatory effects of Aloe vera peel extract

The rapidly emerging rate of antibiotic resistance requires alternative solutions rather than new drugs. Aloe has been used for medical applications and exhibits antimicrobial activity as well as immunomodulation effects. Use of the aloe peel has not been considered, even though it may harbor many useful compounds. In this study, the antimicrobial activity of Aloe vera peel extract in distilled water against Staphylococcus aureus, Bacillus spp.,Enterococcus spp., Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, and Vibrio spp. was ascertained. The number of bacterial colonies were significantly reduced by the application of peel extracts (P<0.05). The antimicrobial activity was especially strong against E. coli and Vibrio spp. (P<0.001). In vivo antimicrobial activity and immunomodulation effects were tested in mice challenged with S. typhimurium DT104. Fecal shedding of S. typhimurium DT104 significantly decreased and intestinal Salmonella specific IgA and IgG titers significantly increased in mice fed with peel extracts. In splenocyte cultures stimulated by concanavalin A, the extract did not affect the production of interleukin IL-2 and interferon-gamma but did promote the production of IL-4 and IL-10. The in vitro and in vivo antimicrobial activities and immunomodulatory properties of A. vera peel extract may be of commercial value. Key words: Aloe vera, antimicrobial effect, immunomodulatory effect.

Structure–function relationship of the saponins from the roots of Platycodon grandiflorum for hemolytic and adjuvant activity

To assess the contribution of the aglycone and sugar chain to the biological activity of saponins from Platycodon grandiflorum, seven structurally consecutive saponins, platycodin D (PD), D2 (PD2), D3 (PD3), platycoside A (PA), E (PE), deapioplatycoside E (DPE), and polygalacin D2 (PGD) were compared for their hemolytic activities and adjuvant potentials on the immune responses to Newcastle disease virus-based recombinant avian influenza vaccine (rL-H5) in mice. Among seven compounds, the order of the hemolytic activity was PGD≈PD>PD2>PA>PD3>PE>DPE. PD, PD2, PA, and PGD significantly not only promoted concanavalin A (Con A)-, lipopolysaccharide (LPS)- and antigen-induced splenocyte proliferation, but enhanced the NK cell activity in mice immunized with rL-H5. PD and PD2 increased the antigen specific IgG, IgG1, IgG2a, and IgG2b antibody titers, while PA and PGD only induce the IgG and IgG1 antibody responses in the immunized mice. However, the other three saponins were not observed for adjuvant activity. The results suggested that the sugar chains attached to C-3, the glycidic moiety at C-28 of aglycone, as well as aglycone affect their biological activities. Interestingly, their hemolytic and adjuvant activities increased with the retention time by reverse phase HPLC analysis. The retention time may be useful for primary estimation of fundamental adjuvanticity of saponin with the same aglycone.

Study of the adjuvanticity of lysine lipopeptides; carbamate analogs elicit strong Th1 and Th2 response to ovalbumin in mice

Bacterial lipoproteins and their synthetic analogs are strong immune modulators of the early host responses. In view of the strong adjuvanticity of bacterial lipopeptide mimics bearing lysine residues, a focused library of lipidated dipeptides and tripeptides has been synthesized with a view to understand the pattern of activity vis a vis the site and extent of lipidation. Compounds 4, 5 and 14 stimulate OVA specific IgG titer, neutralization of antibodies (IgG1 and IgG2a), T lymphocyte sub-sets (CD4/CD8) and its production of soluble mediators for Th1 (IFN-γ)/Th2 (IL-4) cytokines and costimulatory molecules (CD80/CD86) which are ideal traits of immune adjuvants. The results support lipidated lysine dipeptides as potent enhancers of humoral and cell mediated immune responses and thus might become promising immune-adjuvants for self adjuvanted vaccines.

Evaluation of Toxoplasma gondii as a live vaccine vector in susceptible and resistant hosts

BackgroundToxoplasma gondii has been shown to trigger strong cellular immune responses to heterologous antigens expressed by the parasite in the inbred mouse model [1]. We studied the immune response induced by T. gondii as an effective vaccine vector in chickens and rabbits.ResultsT. gondii RH strain was engineered to express the yellow fluorescent protein (YFP) in the cytoplasm. A subcutaneous injection of the transgenic T. gondii YFP in chickens afforded partial protection against the infection of transgenic E. tenella YFP. T. gondii YFP induced low levels of antibodies to YFP in chickens, suggesting that YFP specific cellular immune response was probably responsible for the protective immunity against E. tenella YFP infection. The measurement of T-cell response and IFN-γ production further confirmed that YFP specific Th1 mediated immune response was induced by T. gondii YFP in immunized chickens. The transgenic T. gondii stimulated significantly higher YFP specific IgG titers in rabbits than in chickens, suggesting greater immunogenicity in a T. gondii susceptible species than in a resistant species. Priming with T. gondii YFP and boosting with the recombinant YFP can induce a strong anti-YFP antibody response in both animal species.ConclusionsOur findings suggest that T. gondii can be used as an effective vaccine vector and future research should focus on exploring avirulent no cyst-forming strains of T. gondii as a live vaccine vector in animals.

Phase III Multicenter Clinical Trial of the Sialyl-TN (STn)-Keyhole Limpet Hemocyanin (KLH) Vaccine for Metastatic Breast Cancer

This double-blind, randomized, phase III clinical trial evaluated time to progression (TTP) and overall survival in women with metastatic breast cancer (MBC) who received sialyl-TN (STn) keyhole limpet hemocyanin (KLH) vaccine. Secondary endpoints included vaccine safety and immune response. The study population consisted of 1,028 women with MBC across 126 centers who had previously received chemotherapy and had had either a complete or a partial response or no disease progression. All women received one-time i.v. cyclophosphamide (300 mg/m(2)) 3 days before s.c. injection of 100 μg STn-KLH plus adjuvant (treatment group) or 100 μg KLH plus adjuvant (control group) at weeks 0, 2, 5, and 9. Subsequently, STn-KLH without adjuvant or KLH without adjuvant was then administered monthly for 4 months, and then quarterly until disease progression, without cyclophosphamide. STn-KLH vaccine was well tolerated; patients had mild to moderate injection-site reactions and reversible flu-like symptoms. Week-12 antibody testing revealed high specific IgG titers and a high rate of IgM-to-IgG seroconversion; the median IgG titers in STn-KLH recipients were 320 (anti-ovine submaxillary mucin) and 20,480 (anti-STn), with no detectable antimucin antibodies in the control group. The TTP was 3.4 months in the treatment group and 3.0 months in the control group. The median survival times were 23.1 months and 22.3 months, respectively. Although STn-KLH was well tolerated in this largest to date metastatic breast cancer vaccine trial, no overall benefit in TTP or survival was observed. Lessons were learned for future vaccine study designs.

Recombinant (F1 + V) vaccine protects cynomolgus macaques against pneumonic plague

Cynomolgus macaques, immunised at the 80μg dose level with an rF1+rV vaccine (two doses, three weeks apart), were fully protected against pneumonic plague following inhalational exposure to a clinical isolate of Yersinia pestis (strain CO92) at week 8 of the schedule. At this time, all the immunised animals had developed specific IgG titres to rF1 and rV with geometric mean titres of 96.83±20.93μg/ml and 78.59±12.07μg/ml, respectively, for the 40μg dose group; by comparison, the 80μg dose group had developed titres of 114.4±22.1 and 90.8±15.8μg/ml to rF1 and rV, respectively, by week 8. For all the immunised animals, sera drawn at week 8 competed with the neutralising and protective Mab7.3 for binding to rV antigen in a competitive ELISA, indicating that a functional antibody response to rV had been induced. All but one of the group immunised at the lower 40μg dose-level were protected against infection; the single animal which succumbed had significantly reduced antibody responses to both the rF1 and rV antigens. Although a functional titre to rV antigen was detected for this animal, this was insufficient for protection, indicating that there may have been a deficiency in the functional titre to rF1 and underlining the need for immunity to both vaccine antigens to achieve protective efficacy against plague. This candidate vaccine, which has been evaluated as safe and immunogenic in clinical studies, has now been demonstrated to protect cynomolgus macaques, immunised in the clinical regimen, against pneumonic plague.

Immunogenicity of an AutogenousStreptococcus suisBacterin in Preparturient Sows and Their Piglets in Relation to Protection after Weaning

Streptococcus suis is an important porcine pathogen causing meningitis and other invasive diseases in piglets of different ages. Application of S. suis serotype 2 bacterins to specific-pathogen-free (SPF) weaning piglets has been demonstrated to protect against the homologous serotype. However, autogenous S. suis bacterins are also applied to sows and suckling piglets in the field. Therefore, comparative evaluation of different bacterin immunization regimes, including sow vaccination, was performed in this study. The main objectives were to determine the immunogenicity of an S. suis bacterin in sows prepartum and its influence on active immunization of piglets. Experimental infection of 6- and 8-week-old weaning piglets was performed to elucidate protective efficacies. Humoral immune responses were investigated by an enzyme-linked immunosorbent assay (ELISA) measuring muramidase-released protein (MRP)-specific IgG titers and by opsonophagocytosis assays. Bacterin application elicited high MRP-specific IgG titers in the serum and colostrum of sows, as well as opsonizing antibodies. Piglets from vaccinated sows had significantly higher MRP-specific titers than respective piglets from nonvaccinated sows until 6 weeks postpartum. Vaccination of suckling piglets did not result in high MRP-specific titers nor in induction of opsonizing antibodies. Furthermore, neither vaccination of suckling nor of weaning piglets from immunized sows was associated with a prominent active immune response and protection at 8 weeks postpartum. However, protection was observed in respective 6-week-old weaning piglets, most likely because of protective maternal immunity. In conclusion, this study provides the first results suggesting protective passive maternal immunity for S. suis serotype 2 after bacterin vaccination of sows and a strong inhibitory effect on active immunization of suckling and weaning piglets, leading to highly susceptible growers.

Equine granulocytic anaplasmosis in the Czech Republic

Twelve confirmed cases of equine granulocytic anaplasmosis (EGA) and five additional suspected cases, showing a compatible clinical history and specific IgG titres of 1280 or above, were recorded in the...

Clinical Trials Report: Progress Toward an Effective Malaria Vaccine: RTS,S/ASO1B and RTS,S/ASO2A

Kester et al. conducted a double-blind, randomized trial with 102 healthy adult volunteers assigned to receive either RTS, S/AS01B or RTS,S/AS02A vaccine at 0, 1, and 2 months, and another 36 volunteers who were enrolled as infectivity controls (no vaccine). Malaria challenge was introduced 2– 3 weeks following the vaccine series, and protected vaccinees were rechallenged 5 months later. A total of 52 volunteers were assigned to receive RTS,S/AS01B and 50 volunteers were assigned to receive RTS,S/AS02A. The investigators measured the following immune responses: circumsporozoite protein (CSP)-specific IgG titers, CSP-specific CD4 T cells expressing activation markers (IL-2, IFN-γ, TNF-α, or CD40L), and interferon (IFN)-γ production assayed by ex vivo enzyme-linked immunospots (ELISPOTs).