F van Hemert-Kluitenberg

Wageningen University, Wageningen, Gelderland, Netherlands

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Publications (7)20.43 Total impact

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    ABSTRACT: Inactivated whole virus foot-and-mouth disease (FMD) vaccines are used worldwide for protection against FMD, but not all vaccines induce protection against all genetic variants of the same FMD virus serotype. The aim of this study is to investigate whether the "breadth" of the antibody response against different strains of the same FMD virus serotype in cattle could be improved by using a different adjuvant, a mix of antigens and/or different routes of administration. To this end, six groups of five cattle were vaccinated with different FMD virus serotype A strain vaccines formulated with Montanide ISA 206 VG adjuvant. Antibody responses for homologous and heterologous cross-reactivity against a panel of 10 different FMD virus serotype A strains were tested by a liquid-phase blocking ELISA. Results of cattle vaccinated with ISA 206 VG adjuvanted vaccine were compared with results obtained in a previous study using aluminium hydroxide-saponin adjuvant. No significant effect of adjuvant on the breadth of the antibody response was observed, neither for mixing of antigens nor for the route of administration (subcutaneous vs. intradermal). Comparison of antigen payload, however, increased both homologous and heterologous titres; a 10-fold higher antigen dose resulted in approximately four times higher titres against all tested strains. Our study shows that breadth of the antibody response depends mainly on the vaccine strain; we therefore propose that, for vaccine preparation, only FMD virus strains are selected that, among other important characteristics, will induce a wide antibody response to different field strains.
    Vaccine 08/2014; · 3.49 Impact Factor
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    ABSTRACT: Vaccination has been one of the most important interventions in disease prevention and control. The impact of vaccination largely depends on the quality and suitability of the chosen vaccine. To determine the suitability of the vaccine strain, antigenic matching is usually studied by in vitro analysis. In this study, we performed three in vitro test methods to determine which one gives the lowest variability and the highest discriminatory capacity. Binary ethylenimine inactivated vaccines, prepared from 10 different FMD virus serotype A strains, were used to vaccinate cattle (5 animals for each strain). Antibody titers in 3 weeks post-vaccination (WPV) sera were determined by virus neutralization, neutralization index and liquid phase blocking ELISA. The titers were then used to calculate r1-values. These r1-values were compared to the genetic lineage using receiver operating characteristics (ROC) analysis. In the two neutralization test methods the median titer observed against the test strains differed considerably, and sera of vaccinated animals did not always show the highest titers against their homologous virus strain. When titers were corrected for test strain effect (scaling) the variability (standard error of the mean per vaccinated group) increased because the results were on a different scale, but the discriminatory capacity improved. ROC analysis of the r1-value calculated on both observed and scaled titers showed that only r1-values of the liquid phase blocking ELISA gave a consistent statistically significant result. Under the conditions of the present study, the liquid phase blocking ELISA showed less variation and still had a higher discriminatory capacity.
    Clinical and vaccine Immunology: CVI 03/2014; · 2.37 Impact Factor
  • P L Eblé, K Weerdmeester, F van Hemert-Kluitenberg, A Dekker
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    ABSTRACT: The aim of this study was to investigate whether intradermal (ID) vaccination against foot-and-mouth disease (FMD) is suitable as an alternative for the usually used intramuscular (IM) route. We compared vaccine efficacy in groups of pigs in which vaccine administration differed with respect to antigen payload of the vaccine, administrated volume and administration route. When compared with pigs that were IM vaccinated with a full dose vaccine with a standard antigen payload, pigs vaccinated ID with 1/10 dose of the same vaccine were equally protected against clinical disease and subclinical virus shedding. The ID vaccinated pigs were protected against virus shedding at a significant lower VN-titre as compared to IM vaccinated pigs, suggesting that immune responses other than neutralising antibodies also contributed to protection. We conclude that the ID route might be a good alternative for IM application, as ID application might induce a very efficient immunological response against FMD and, moreover, because the dose required by the ID route is lower compared to the IM route, ID application may reduce the production costs per dose of FMD vaccine markedly.
    Vaccine 02/2009; 27(8):1272-8. · 3.49 Impact Factor
  • K Orsel, H I J Roest, E M Elzinga-Bril, F van Hemert-Kluitenberg, A Dekker
    The Veterinary record 07/2008; 162(23):753-4. · 1.63 Impact Factor
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    P L Eblé, M G M de Bruin, A Bouma, F van Hemert-Kluitenberg, A Dekker
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    ABSTRACT: This study compares the immune responses and protection induced by intra-typic heterologous vaccination with that induced by homologous vaccination against challenge with foot-and-mouth disease virus (FMDV). Humoral and cell-mediated immune responses and protection against challenge with FMDV O Taiwan were examined in a non-vaccinated group, a group vaccinated with O Taiwan FMD vaccine and a group vaccinated with O Manisa FMD vaccine. Five pigs from each group were challenged with FMDV type O Taiwan 14 days after vaccination and five other pigs were contact-exposed to the inoculated pigs. Both homologous and heterologous vaccination protected against challenge with FMDV O Taiwan at 2 weeks after vaccination. In the heterologous vaccinated group, cross-neutralizing antibody titres against O Taiwan could be detected although the ratio 'r(1)' was 0.4, which was significantly smaller than the critical r-value. Cell-mediated immune responses were detected after both homologous and heterologous vaccination. Virus-induced in vitro lymphocyte (cross-) proliferation and production of both a Th1-type (IFN-gamma) and a Th2-type (IL-10) cytokine response were demonstrated in cultures of peripheral blood mononuclear cells (PBMC). The findings show that heterologous (emergency) vaccination can prevent clinical disease and shedding of virus. The induction of the cell-mediated immune responses after (heterologous) vaccination needs more research but data on these responses might provide additional tools for both vaccine choice and vaccine development.
    Vaccine 03/2006; 24(9):1274-81. · 3.49 Impact Factor
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    ABSTRACT: The objective of this study was to investigate whether and at what time interval could vaccination reduce transmission of foot-and-mouth disease virus (FMDV) among pigs. Reduction of virus transmission by vaccination was determined experimentally. Transmission of FMDV was studied in three groups of ten pigs: one non-vaccinated group and two groups that were vaccinated 7 days (-7 dpi) and 14 days before inoculation (-14 dpi), respectively. Five randomly selected pigs from each group were inoculated with FMDV type O Taiwan, while the other five pigs left in the groups were exposed to the inoculated pigs by direct contact. Clinical signs were recorded, virus isolation and RT-PCR were carried out on oropharyngeal fluid (OPF), and the neutralizing antibody titres and the antibody response against non-structural (NS) proteins of FMDV were determined. No virus transmission was observed in the -14 dpi group, whereas virus transmission was observed in all contact pigs affecting both the non-vaccinated and the -7 dpi group. The reproduction ratio R in the -14 dpi vaccinated group was significantly lower than that of the non-vaccinated group. This study confirms the potential of vaccination as an important tool to reduce transmission of FMDV.
    Vaccine 04/2004; 22(11-12):1372-8. · 3.49 Impact Factor
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    A Dekker, F van Hemert-Kluitenberg, C Baars, C Terpstra
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    ABSTRACT: Isotype specific ELISAs to detect antibodies against swine vesicular disease, which may help to estimate the moment of infection, were developed and validated on sera from pigs experimentally infected with four different isolates of swine vesicular disease virus. Virus specific IgM antibodies could be detected from days 3-49 and occasionally up to day 91 after infection. IgG1 antibodies were first detected at day 8 and IgG2 at day 11. IgA antibodies coincided with IgG1 antibodies, but antibody titres varied widely. From the results obtained with the sera from the experimentally infected pigs, we calculated the day at which 50% of the pigs had become positive (D50). A D50 of 5, 4, 12, 12 and 24 days was calculated, respectively, for the appearance of antibodies in the virus neutralization test, the IgM, total IgG, IgG1 and IgG2 ELISA. A D50 of 49 days was calculated for the disappearance of IgM antibodies. The isotype specific ELISAs proved to be valuable tools to study the epidemiology of the disease.
    Epidemiology and Infection 05/2002; 128(2):277-84. · 2.49 Impact Factor