@article{SinghKingstonGuptaetal.2015, author = {Singh, Amit K. and Kingston, Joseph J. and Gupta, Shishir K. and Batra, Harsh V.}, title = {Recombinant Bivalent Fusion Protein rVE Induces CD4+ and CD8+ T-Cell Mediated Memory Immune Response for Protection Against Yersinia enterocolitica Infection}, series = {Frontiers in Microbiology}, volume = {6}, journal = {Frontiers in Microbiology}, number = {1407}, doi = {10.3389/fmicb.2015.01407}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-136114}, year = {2015}, abstract = {Studies investigating the correlates of immune protection against Yersinia infection have established that both humoral and cell mediated immune responses are required for the comprehensive protection. In our previous study, we established that the bivalent fusion protein (rVE) comprising immunologically active regions of Y pestis LcrV (100-270 aa) and YopE (50-213 aa) proteins conferred complete passive and active protection against lethal Y enterocolitica 8081 challenge. In the present study, cohort of BALB/c mice immunized with rVE or its component proteins rV, rE were assessed for cell mediated immune responses and memory immune protection against Y enterocolitica 8081 rVE immunization resulted in extensive proliferation of both CD4 and CD8 T cell subsets; significantly high antibody titer with balanced IgG1: IgG2a/IgG2b isotypes (1:1 ratio) and up regulation of both Th1 (INF-\(\alpha\), IFN-\(\gamma\), IL 2, and IL 12) and Th2 (IL 4) cytokines. On the other hand, rV immunization resulted in Th2 biased IgG response (11:1 ratio) and proliferation of CD4+ T-cell; rE group of mice exhibited considerably lower serum antibody titer with predominant Th1 response (1:3 ratio) and CD8+ T-cell proliferation. Comprehensive protection with superior survival (100\%) was observed among rVE immunized mice when compared to the significantly lower survival rates among rE (37.5\%) and rV (25\%) groups when IP challenged with Y enterocolitica 8081 after 120 days of immunization. Findings in this and our earlier studies define the bivalent fusion protein rVE as a potent candidate vaccine molecule with the capability to concurrently stimulate humoral and cell mediated immune responses and a proof of concept for developing efficient subunit vaccines against Gram negative facultative intracellular bacterial pathogens.}, language = {en} } @article{MuellerStoetterKalluvyaetal.2015, author = {Mueller, A. and Stoetter, L. and Kalluvya, S. and Stich, A. and Majinge, C. and Weissbrich, B. and Kasang, C.}, title = {Prevalence of hepatitis B virus infection among health care workers in a tertiary hospital in Tanzania}, series = {BMC Infectious Diseases}, volume = {15}, journal = {BMC Infectious Diseases}, number = {386}, doi = {10.1186/s12879-015-1129-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141786}, year = {2015}, abstract = {Background: Sub-Saharan Africa has a high prevalence of hepatitis B virus (HBV) infections. Health care workers (HCWs) are at high risk of contracting HBV infection through their occupation. Vaccination of HCWs against HBV is standard practice in many countries, but is often not implemented in resource-poor settings. We aimed with this cross-sectional study to determine HBV prevalence, HCW vaccination status, and the risk factors for HCWs contracting HBV infection in Tanzania. Methods: We enrolled 600 HCWs from a tertiary Tanzanian hospital. Their demographics, medical histories, HBV vaccination details and risk factors for contracting blood-borne infections were collected using a standardized questionnaire. Serum samples were tested for HBV and hepatitis C virus (HCV) markers by ELISA techniques, PCR and an anti-HBs rapid test. HCWs were divided in two subgroups: those at risk of contracting HBV (rHCW 79.2 \%) via exposure to potentially infectious materials, and those considered not at risk of contracting HBV (nrHCW, 20.8 \%). Results: The overall prevalence of chronic HBV infection (HBsAg+, anti-HBc+, anti-HBs-) was 7.0 \% (42/598). Chronic HBV infection was found in 7.4 \% of rHCW versus 5.6 \% of nrHCW(p-value = 0.484). HCWs susceptible to HBV (HBsAg-, anti-HBc-, anti-HBs-) comprised 31.3 \%. HBV immunity achieved either by healed HBV infection (HBsAg-, anti-HBc+, anti-HBs+) or by vaccination (HBsAg-, anti-HBc-, anti-HBs+) comprised 36.5 \% and 20.2 \%, respectively. 4.8 \% of participants had indeterminate results (HBsAg-, anti-HBc+, anti-HBc-IgM-, anti-HBs-). Only 77.1 \% of HCWs who received a full vaccination course had an anti-HBs titer > 10 ml/U. An anti-HBs point-of-care test was 80.7 \% sensitive and 96.9 \% specific. There was a significantly higher risk for contracting HBV (anti-HBc+) among those HCW at occupational risk (rHCW) of older age (odds ratios (OR) in rHCW 3.297, p < 0.0001 vs. nrHCW 1.385, p = 0.606) and among those HCW being employed more than 11 years (OR 2.51, p < 0.0001***). HCV prevalence was low (HCV antibodies 1.2 \% and HCV-RNA 0.3 \%). Conclusions: Chronic HBV infection is common among Tanzanian HCWs. One third of HCWs were susceptible to HBV infection, highlighting the need for vaccination. Due to high prevalence of naturally acquired immunity against HBV pre-testing might be a useful tool to identify susceptible individuals.}, language = {en} } @article{SauerbreiLangenhanBrandstaedtetal.2014, author = {Sauerbrei, A. and Langenhan, T. and Brandst{\"a}dt, A. and Schmidt-Ott, R. and Krumbholz, A. and Girschick, H. and Huppertz, H. and Kaiser, P. and Liese, J. and Streng, A. and Niehues, T. and Peters, J. and Sauerbrey, A. and Schroten, H. and Tenenbaum, T. and Wirth, S. and Wutzler, P.}, title = {Prevalence of antibodies against influenza A and B viruses in children in Germany, 2008 to 2010}, series = {Eurosurveillance}, volume = {19}, journal = {Eurosurveillance}, number = {5}, issn = {1560-7917}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117347}, pages = {20687}, year = {2014}, abstract = {The prevalence of influenza A and B virus-specific IgG was determined in sera taken between 2008 and 2010 from 1,665 children aged 0-17 years and 400 blood donors in Germany. ELISA on the basis of whole virus antigens was applied. Nearly all children aged nine years and older had antibodies against influenza A. In contrast, 40\% of children aged 0-4 years did not have any influenza A virus-specific IgG antibodies. Eighty-six percent of 0-6 year-olds, 47\% of 7-12 year-olds and 20\% of 13-17 year-olds were serologically naive to influenza B viruses. By the age of 18 years, influenza B seroprevalence reached approximately 90\%. There were obvious regional differences in the seroprevalence of influenza B in Germany. In conclusion, seroprevalences of influenza A and influenza B increase gradually during childhood. The majority of children older than eight years have basal immunity to influenza A, while comparable immunity against influenza B is only acquired at the age of 18 years. Children aged 0-6 years, showing an overall seroprevalence of 67\% for influenza A and of 14\% for influenza B, are especially at risk for primary infections during influenza B seasons.}, language = {en} } @article{RoierLeitnerIwashkiwetal.2012, author = {Roier, Sandro and Leitner, Deborah R. and Iwashkiw, Jeremy and Schild-Pr{\"u}fert, Kristina and Feldman, Mario F. and Krohne, Georg and Reidl, Joachim and Schild, Stefan}, title = {Intranasal Immunization with Nontypeable Haemophilus influenzae Outer Membrane Vesicles Induces Cross-Protective Immunity in Mice}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {8}, doi = {10.1371/journal.pone.0042664}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-135201}, pages = {e42664}, year = {2012}, abstract = {Haemophilus influenzae is a Gram-negative human-restricted bacterium that can act as a commensal and a pathogen of the respiratory tract. Especially nontypeable H. influenzae (NTHi) is a major threat to public health and is responsible for several infectious diseases in humans, such as pneumonia, sinusitis, and otitis media. Additionally, NTHi strains are highly associated with exacerbations in patients suffering from chronic obstructive pulmonary disease. Currently, there is no licensed vaccine against NTHi commercially available. Thus, this study investigated the utilization of outer membrane vesicles (OMVs) as a potential vaccine candidate against NTHi infections. We analyzed the immunogenic and protective properties of OMVs derived from various NTHi strains by means of nasopharyngeal immunization and colonization studies with BALB/c mice. The results presented herein demonstrate that an intranasal immunization with NTHi OMVs results in a robust and complex humoral and mucosal immune response. Immunoprecipitation revealed the most important immunogenic proteins, such as the heme utilization protein, protective surface antigen D15, heme binding protein A, and the outer membrane proteins P1, P2, P5 and P6. The induced immune response conferred not only protection against colonization with a homologous NTHi strain, which served as an OMV donor for the immunization mixtures, but also against a heterologous NTHi strain, whose OMVs were not part of the immunization mixtures. These findings indicate that OMVs derived from NTHi strains have a high potential to act as a vaccine against NTHi infections.}, language = {en} } @article{HolzmannLittigBraunischKrankeetal.2021, author = {Holzmann-Littig, Christopher and Braunisch, Matthias Christoph and Kranke, Peter and Popp, Maria and Seeber, Christian and Fichtner, Falk and Littig, Bianca and Carbajo-Lozoya, Javier and Allwang, Christine and Frank, Tamara and Meerpohl, Joerg Johannes and Haller, Bernhard and Schmaderer, Christoph}, title = {COVID-19 vaccination acceptance and hesitancy among healthcare workers in germany}, series = {Vaccines}, volume = {9}, journal = {Vaccines}, number = {7}, issn = {2076-393X}, doi = {10.3390/vaccines9070777}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242627}, year = {2021}, abstract = {Vaccination hesitancy is a threat to herd immunity. Healthcare workers (HCWs) play a key role in promoting Coronavirus disease 2019 (COVID-19) vaccination in the general population. We therefore aimed to provide data on COVID-19 vaccination acceptance/hesitancy among German HCWs. For this exploratory, cross-sectional study, an online survey was conducted in February 2021. The survey included 54 items on demographics; previous vaccination behavior; trust in vaccines, physicians, the pharmaceutical industry and health politics; fear of adverse effects; assumptions regarding the consequences of COVID-19; knowledge about vaccines; and information seeking behavior. Odds ratios with 95\% confidence intervals were calculated and chi-square tests were performed. Four thousand five hundred surveys were analyzed. The overall vaccination acceptance was 91.7\%. The age group ≤20 years showed the lowest vaccination acceptance. Factors associated with vaccination hesitancy were lack of trust in authorities and pharmaceutical companies. Attitudes among acquaintances were associated with vaccination hesitancy too. Participants with vaccination hesitancy more often obtained information about COVID-19 vaccines via messenger services or online video platforms and underperformed in the knowledge test. We found high acceptance amongst German HCWs. Several factors associated with vaccination hesitancy were identified which could be targeted in HCW vaccination campaigns.}, language = {en} }