Skeletal muscle toxicity associated with tyrosine kinase inhibitor therapy in patients with chronic myeloid leukemia
Janssen, L. ; Frambach, S.J.C.M. ; Allard, N.A.E. ; Hopman, M.T.E. ; Schirris, T.J.J. ; Voermans, N.C. ; Rodenburg, R.J. ; Blijlevens, N.M.A. ; Timmers, S. - \ 2019
Leukemia 33 (2019). - ISSN 0887-6924 - p. 2116 - 2120.
Economic feasibility of animal welfare improvements in Dutch intensive livestock production: A comparison between broiler, laying hen, and fattening pig farms
Gocsik, E. ; Oude Lansink, A.G.J.M. ; Voermans, G. ; Saatkamp, H.W. - \ 2015
Livestock Science 182 (2015). - ISSN 1871-1413 - p. 38 - 53.
Economic feasibility, Stochastic simulation modeling, Decision making, Livestock production
This study compared the economic feasibility of production systems with different levels of animal welfare (AW) in the broiler, laying hen, and fattening pig sectors. Economic feasibility over a five-year time horizon was assessed using stochastic bio-economic simulation models. The results suggest that the main determinant of economic feasibility in each sector is the producer price. It is not only the level of the price premium but also the certainty and variability of this premium that is important in the decision to convert to an alternative system. From the perspective of the farm, different approaches should be followed in the three sectors to further develop the market for products with higher levels of AW. The results imply that the broiler sector has the best perspective in the short to medium term for developing this market. In the fattening pig sector, conversion options should be made more financially attractive, for example by increasing price premiums or providing conversion subsidies. The laying hen sector has the worst prospects for improving AW in the short to medium term. Therefore, given the current production systems in this sector, producer price premiums need to be increased in order to increase the adoption of alternative production systems.
|TAG biedt logistieke keten veel voordelen: efficiënter van boer naar consument
Voermans, F. ; Hoofman, R. ; Westra, E.H. - \ 2013
PT industrieel management 2013 (2013)4. - ISSN 1571-9405 - p. 22 - 23.
Made by Fairtrade : de Fairtrade Gemeente Campagne als impuls voor de Fairtrade markt
Voermans, K. ; Hendriksen, A. ; Oosterveer, P.J.M. ; Rossing, G. - \ 2012
Wageningen : Wageningen UR, Wetenschapswinkel (Rapport / Wageningen UR, Wetenschapswinkel 282) - ISBN 9789085857389 - 33
gemeenten - fair trade - gelderland - bewustwording - communicatie - maatschappelijk verantwoord ondernemen - samenwerking - multi-stakeholder processen - municipalities - fair trade - gelderland - conscientization - communication - corporate social responsibility - cooperation - multi-stakeholder processes
Dit rapport probeert allereerst een overzicht te geven van Fairtrade strategieën door enerzijds het beschrijven van de ontwikkelingsfasen binnen de Fairtrade beweging en anderzijds het belichten van bedrijfsstrategieën op lokaal niveau. Hiermee wordt een kader geschapen voor de aanzet tot dit onderzoeksproject van de Wetenschapswinkel van Wageningen UR: de vraag van de werkgroep Fairtrade Gemeente Renkum om ondersteuning bij het behalen van de titel Fairtrade Gemeente Renkum. Besloten is om de gemeente Renkum als voorbeeldcasus te gebruiken om hiermee andere gemeenten die de titel Fairtrade Gemeente willen halen te inspireren. Om de gemeente Renkum te ondersteunen in haar streven erkend te worden als Fairtrade Gemeente zijn scenario’s ontwikkeld met als doel verschillende keuzemogelijkheden te laten zien die kunnen leiden tot de status van Fairtrade Gemeente Renkum. Op basis van het gekozen scenario is een monitoring- & evaluatiestrategie ontwikkeld en is een lange termijn communicatieplan geschreven.
To claim or not to claim
Fortuin, F.T.J.M. ; Jong, L. de - \ 2010
Wageningen : Stichting Food Valley i.s.m. Dijkstra Voermans Advocatuur & Notariaat (Food valley innovation insights dl. 3) - ISBN 9789081609333 - 32
voedingsmiddelenwetgeving - eu regelingen - etiketteren van voedingsmiddelen - voeding en gezondheid - food legislation - eu regulations - nutrition labeling - nutrition and health
Verslag van een themabijeenkomst welke als doel had om de sector concrete handvatten aan te reiken voor het aanvragen én realiseren van een gezondheidsclaim.
Monitoring ClimecoVent-systeem in de praktijk - Technisch, teeltkundig en economisch onderzoek naar een energiezuinige kas bij kwekerij Grenspaal B.V.
Raaphorst, M.G.M. ; Voermans, J. - \ 2010
Bleiswijk : Wageningen (Rapporten GTB 1032) - 54
kassen - innovaties - schaduw - kooldioxide - temperatuur - tomaten - glastuinbouw - energiebesparing - greenhouses - innovations - shade - carbon dioxide - temperature - tomatoes - greenhouse horticulture - energy saving
De tomatentelers Noud en Roy Steegh zijn in januari 2009 op kwekerij Grenspaal te Wellerlooi (L) gestart met een nieuwe kas, voorzien van het ClimecoVent-systeem. Met het ClimecoVent-systeem wordt beoogd zodanig energie te besparen dat de warmtevraag bij een tomatenteelt neerkomt op een aardgasverbruik van 25 tot 30 m3/m2. De productiedoelen liggen gelijk aan die van een standaard tomatenteelt. Gezien het innovatieve en energiezuinige karakter van het ClimecoVent-systeem, heeft Wageningen UR in samenwerking met Climeco het systeem bij kwekerij Grenspaal over een tijdsspanne van ruim een jaar gemonitord in opdracht van het programma “Kas als Energiebron”. Doordat minder gas is gebruikt voor de verwarming van de kas is ook minder CO2 beschikbaar. In combinatie met de schaduwwerking van het extra scherm zou hiermee mogen worden verwacht dat het productieniveau achterblijft, maar dat is niet gebleken.
The adventure of greening the University : rol van het studentennetwerk Morgen bij kennisuitwisseling voor duurzame ontwikkeling binnen het hoger onderwijs
Voermans, K. ; Hendriksen, A. ; Drunen, M. van - \ 2010
Wageningen : Wetenschapswinkel Wageningen UR (Rapport / Wetenschapswinkel Wageningen UR 265) - ISBN 9789085851967 - 31
kennis - studenten - studentenparticipatie - hoger onderwijs - universiteiten - communicatie - vergroening - bedrijfsvoering - nederland - kennisoverdracht - duurzame ontwikkeling - actor-network theorie - netwerken - knowledge - students - student participation - higher education - universities - communication - greening - management - netherlands - knowledge transfer - sustainable development - actor-network theory - networks
De Wetenschapswinkel heeft in opdracht van het studentennetwerk Morgen een onderzoeksproject uitgevoerd naar duurzame ontwikkeling binnen universiteiten en hogescholen. Het doel van het project ‘The Adventure of Greening the University’ is om ‘Morgen’ te adviseren hoe het proces van kennisuitwisseling rondom duurzame ontwikkeling binnen het hoger onderwijs te versnellen.
Validated RealTime reverse transcriptase PCR methods for the diagnosis and pathotyping of Eurasian H7 avian influenza viruses
Slomka, M.J. ; Pavlidis, T. ; Coward, V.J. ; Voermans, J. ; Koch, G. ; Hanna, A. ; Banks, J. ; Brown, I.H. - \ 2009
Influenza and Other Respiratory Viruses 3 (2009)4. - ISSN 1750-2640 - p. 151 - 164.
polymerase-chain-reaction - cleavage site - a virus - low-pathogenicity - hemagglutinin - h5 - subtypes - surveillance - replication - genes
Background Avian influenza (AI) caused by H7 AI viruses (AIVs) of both low pathogenicity (LP) and high pathogenicity (HP) are notifiable poultry diseases. Objectives Design and validate two RealTime reverse transcriptase polymerase chain reactions (RRT PCRs) for Eurasian H7 AIV detection and pathotyping. Methods The H7 RRT PCRs amplified within the (i) HA2 and (ii) cleavage site CS regions of the haemagglutinin gene. Both were validated against 65 H7 AIVs, 57 non-H7 AIVs and 259 poultry swabs in comparison to M gene (AI generic) RRT PCR and virus isolation (VI). An additional 38 swabs and 20 tissue specimens extended validation against M gene RRT PCR. Results Both H7 RRT PCRs amplified all 61 Eurasian lineage H7 AIVs and none of 57 non-H7 AIVs. A total of 297 poultry swabs were used to determine diagnostic sensitivity and specificity relative to M gene RRT PCR, sensitivity was 95 center dot 4% and 64 center dot 6% for the HA2 and CS RRT PCRs respectively, and specificity 97 center dot 9% and 99 center dot 6% respectively. The H7 HA2 RRT PCR was more sensitive than VI. This was emphasized by analysis of 37 swabs from turkeys infected experimentally with HPAI H7N1 virus sampled at 24 hours post-inoculation and LPAI H7N1 chicken infections sampled at 40-64 hours. Although less sensitive, usefulness of the H7 CS RRT PCR was confirmed by the correct molecular pathotyping for all 61 Eurasian lineage H7 AIVs tested. Conclusions The high sensitivity of H7 HA2 RRT PCR confirms its suitability for use in poultry surveillance and disease diagnosis. H7 CS RRT PCR provides an opportunity for rapid pathotyping of H7 AIVs.
Reverse breeding: a novel breeding approach based on engineered meiosis
Dirks, R. ; Dun, K.P.M. van; Snoo, B. de; Berg, M. van den; Lelivelt, C.L.C. ; Voermans, W. ; Woudenberg, L. ; Wit, J.P.C. de; Reinink, K. ; Schut, J.W. ; Jong, J.H.S.G.M. de; Wijnker, T.G. - \ 2009
Plant Biotechnology Journal 7 (2009)9. - ISSN 1467-7644 - p. 837 - 845.
cytoplasmic male-sterility - meiotic prophase-i - chromosome segregation - arabidopsis-thaliana - gene - recombination - dmc1 - protein - plants - heterosis
Reverse breeding (RB) is a novel plant breeding technique designed to directly produce parental lines for any heterozygous plant, one of the most sought after goals in plant breeding. RB generates perfectly complementing homozygous parental lines through engineered meiosis. The method is based on reducing genetic recombination in the selected heterozygote by eliminating meiotic crossing over. Male or female spores obtained from such plants contain combinations of non-recombinant parental chromosomes which can be cultured in vitro to generate homozygous doubled haploid plants (DHs). From these DHs, complementary parents can be selected and used to reconstitute the heterozygote in perpetuity. Since the fixation of unknown heterozygous genotypes is impossible in traditional plant breeding, RB could fundamentally change future plant breeding. In this review, we discuss various other applications of RB, including breeding per chromosome
|Improved cryopreservation of peripheral blood stem cells using a theoretically optimized freezing curve
Tijssen, M.R. ; Woelders, H. ; Vries, A. de; Schoot, C. van der; Voermans, C. ; Lagerberg, J.W.M. - \ 2008
Cryo-Letters 29 (2008)1. - ISSN 0143-2044 - p. 79 - 80.
Background: The freezing curve currently used for the cryopreservation of autologous peripheral blood stem cell (PBSC) transplants has been empirically determined. Although the use of cryopreserved PBSC is successful and usually leads to rapid hematopoietic recovery, the freezethawingprocess is known to induce a significant amount of cell death. Furthermore, the infusion of DMSO, which is used to protect the cells against damage induced by freezing, can cause morbidity. Therefore, optimizing the current cryopreservation protocol (10% DMSO, slow linear cooling) by using theoretically optimized freezing curves and lower DMSO concentration might improve the results after autologous transplantation. Study Design and Methods: The model of Woelders & Chaveiro was used to predict optimal freezing curves for 5 and 10% DMSO. CD34+ selected and unselected peripheral blood stem cell suspensions were cryopreserved using either the current protocol or the new freezing curves. Postthaw quality was evaluated using cell recovery, colony formation and megakaryocyte outgrowth. Results: Using literature values for water and DMSO permeability, “optimal” freezing curves were calculated. In contrast to the currently used linear freezing curve, the model predicts freezing curves with different freezing rates at different temperatures. With 10% DMSO, the use of the calculated freezing curve resulted in increased post-thaw viability of CD34+ cells, colony formation and megakaryocyte outgrowth. Lowering the DMSO concentration to 5%, resulted, by itself, in improved post-thaw viability and functionality, which was not further improved by using the theoretically optimized freezing curve. Conclusions: Our results indicate that the current cryopreservation method for PBSC can be improved by either lowering the DMSO concentration to 5% or by using the theoretically optimized freezing curve. Infusion of a lower concentration of DMSO and less death cells might reduce the harmful side effects of autologous PBSC transplantation.
Improved postthaw viability and in vitro functionality of peripheral blood hematopoietic progenitor cells after cryopreservation with a theoretically optimized freezing curve
Tijssen, M.R. ; Woelders, H. ; Vries - van Rossen, A. de; Schoot, C. van der; Voermans, C. ; Lagerberg, J.W.M. - \ 2008
Transfusion 48 (2008)5. - ISSN 0041-1132 - p. 893 - 901.
cd34(+) cells - clinical toxicity - stem-cells - apoptosis - permeability - infusion - grafts - marrow - death
The freezing curve currently used for the cryopreservation of peripheral blood stem cell transplants (PBSCTs) has been determined empirically. Although the use of cryopreserved PBSCTs is successful and usually leads to rapid hematopoietic recovery, the freeze-thawing process is known to induce a significant degree of cell death. Furthermore, the infusion of dimethyl sulfoxide (DMSO), used to protect the cells against damage induced by freezing, can cause morbidity. Therefore, optimizing the current cryopreservation protocol (with 10% DMSO and a slow linear cooling curve) with theoretically optimized freezing curves and a lower DMSO concentration might improve the recovery after transplantation
|Validation Of a Commercially Available N1 Antibody Competitive Elisa Kit
Koch, G. ; Voermans, J.J.M. ; Goot, J.A. van der - \ 2007
Identification of sensitive and specific Avian influenza PCR methods through blind ring trials organized in the European Union
Slomka, M.J. ; Coward, V.J. ; Banks, J. ; Löndt, B.Z. ; Brown, I.H. ; Voermans, J.J.M. ; Koch, G. ; Handberg, K.J. ; Jörgensen, P.H. ; Cherbonnel-Pansart, M. ; Jestin, V. ; Cattoli, G. ; Capua, I. ; Ejdersund, A. ; Thoren, P. ; Czifra, G. - \ 2007
Avian Diseases 51 (2007). - ISSN 0005-2086 - p. 227 - 234.
a viruses - rt-pcr - hemagglutinin - replication - h5
Many different polymerase chain reaction (PCR) protocols have been used for detection and characterization of avian influenza (AI) virus isolates, mainly in research settings. Blind ring trials were conducted to determine the most sensitive and specific AI PCR protocols from a group of six European Union (EU) laboratories. In part 1 of the ring trial the laboratories used their own methods to test a panel of 10 reconstituted anonymized clinical specimens, and the best methods were selected as recommended protocols for part 2, in which 16 RNA specimens were tested. Both panels contained H5, H7, other AI subtypes, and non-AI avian pathogens. Outcomes included verification of 1) generic AI identification by highly sensitive and specific M-gene real-time PCR, and 2) conventional PCRs that were effective for detection and identification of H5 and H7 viruses. The latter included virus pathotyping by amplicon sequencing. The use of recommended protocols resulted in improved results among all six laboratories in part 2, reflecting increased sensitivity and specificity. This included improved H5/H7 identification and pathotyping observed among all laboratories in part 2. Details of these PCR methods are provided. In summary, this study has contributed to the harmonization of AI PCR protocols in EU laboratories and influenced AI laboratory contingency planning following the first European reports of H5N1 highly pathogenic AI during autumn 2005.
Improved post-thaw viability and in vitro functionality of peripheral blood hematopoietic progenitor cells after cryopreservation with a theoretically optimized freezing curve
Tijssen, M.R. ; Woelders, H. ; Vries, A. de; Schoot, C. van der; Voermans, C. ; Lagerberg, J.W.M. - \ 2007
Blood : journal of the American Society of Hematology 110 (2007)11. - ISSN 0006-4971 - p. 370A - 370A.
Oral transmission of porcine reproductive and respiratory syndrome virus by muscle of experimentally infected pigs
Linden, I.F.A. van der; Bril, E.M. ; Voermans, J.J.M. ; Rijn, P.A. van; Pol, J.M.A. ; Martin, R. ; Steverink, P.J.G.M. - \ 2003
Veterinary Microbiology 97 (2003)1-2. - ISSN 0378-1135 - p. 45 - 54.
polymerase-chain-reaction - lelystad virus
The current study was performed to determine if porcine reproductive and respiratory syndrome virus (PRRSV) could be transmitted to pigs by feeding muscle tissue obtained from recently infected pigs. Muscle obtained from pigs infected with either a European strain (EU donor pigs) or American strain (US donor pigs) of PRRSV was fed to PRRSV-free receiver pigs. The donor pigs were slaughtered 11 days post-infection (dpi). PRRSV was detected by conventional virus isolation in muscle at 11 dpi from 7 of 12 EU donor pigs and 5 of 12 US donor pigs. In contrast to conventional virus isolation, all muscle samples from infected pigs were positive for viral nucleic acid by PCR, except for muscle from one animal infected with the American strain of PRRSV. Five hundred grams of raw semimembranosus muscle from each of the donor pigs was fed over a 2 days period (250 g per day) to each of two receiver pigs (48 receiver pigs). The receiver pigs were housed separately in five groups. One of the five groups was fed muscle obtained from US donor pigs that was also spiked with the American strain of PRRSV. Sentinel pigs were placed in-contact with the group of receiver pigs fed spiked muscle. All receiver pigs became viraemic by 6 days post-feeding (dpf). There was evidence of horizontal transmission with sentinel pigs, in-contact with receiver pigs, becoming viraemic. The study demonstrates that PRRSV could be infectious through the oral route via the feeding of meat obtained from recently infected pigs.
Virological kinetics and immunological responses to a porcine reproductive and respiratory syndrome virus infection of pigs at different ages.
Linden, I.F.A. van der; Voermans, J.J.M. ; Linde-Bril, E.M. van der; Bianchi, A.T.J. ; Steverink, P.J.G.M. - \ 2003
Vaccine 21 (2003)17-18. - ISSN 0264-410X - p. 1952 - 1957.
serotype prrsv vaccine - aujeszkys disease - lelystad-virus - strains - swine - challenge - american
The objective of this study was to measure the effect of two variables (pig age and virus strain) on selected responses (clinical signs, viraemia, virus excretion and seroconversion) of pigs following exposure to porcine reproductive and respiratory syndrome (PRRS) virus. Therefore, young (6 till 8 weeks old) and old (6 months old) pigs were infected with 3 different PRRSV strains, i.e. LV ter Huurne (LVTH), LV4.2.1 and SDSU#73. Regardless of the strain used for exposure, young pigs were more susceptible to infection as shown by a higher number of viraemic and virus excreting pigs. Strain differences were also evident. LV ter Huurne induced virus excretion in a higher number of pigs and with a higher virus titre, whereas SDSU#73 induced most severe clinical signs. LV4.2.1 induced viraemia and virus excretion in a low number of pigs. The kinetics of the antibody response differed per virus strain. The results presented here are useful in developing a less expensive standardised infection model, consisting of young pigs intranasally infected with a virulent PRRSV strain, to study the efficacy of new vaccine strains.
Erratum to 'Effects of a porcine reproductive and respiratory syndrome virus infection on the development of the immune response against pseudorabies virus'
Bruin, M.G. de; Samsom, J.N. ; Voermans, J.J. ; Rooij, E.M. van; Visser, Y.E. de; Bianchi, A.T.J. - \ 2001
Veterinary Immunology and Immunopathology 78 (2001). - ISSN 0165-2427 - p. 215 - 216.
Kostprijs, stro en kwaliteitsborging zetten toon in werkplan 2000
Swinkels, H. ; Voermans, J. - \ 2000
Praktijkonderzoek varkenshouderij 14 (2000)2. - ISSN 1382-0346 - p. 4 - 5.
varkenshouderij - productiekosten - dierenwelzijn - ligstro - kwaliteitsnormen - werkplannen - onderzoek - pig farming - production costs - animal welfare - litter - quality standards - working plans - research
Bedrijfssystemen met een lage kostprijs staan hoog op de onderzoeksagenda van het PW, terwijl LNV de ontwikkeling van (biologische) bedrijfssystemen met stro en strooisel initieert. Vanuit andere opdrachtgevers is veel vraag naar instrumenten voor hetcertificeren van de productie van varkensvlees.
Discrimination of different subsets of cytolytic cells in pseudorabies virus-immune and naive pigs
Bruin, T.G.M. de; Rooij, E.M.A. van; Visser, Y.E. de; Voermans, J.J.M. ; Samsom, J.N. ; Kimman, T.G. ; Bianchi, A.T.J. - \ 2000
Journal of General Virology 81 (2000)6. - ISSN 0022-1317 - p. 1529 - 1537.
We previously observed that pseudorabies virus (PRV)-induced, cell-mediated cytolysis in pigs includes killing by natural killer (NK) cells. We also observed that IL-2 stimulation in vitro of naive PBMC expands porcine NK cells. The purpose of this study was to compare the phenotypes of the cytolytic subsets stimulated in vitro by PRV and by IL-2. PBMC were isolated from blood of PRV-immune and naive pigs and stimulated in vitro with PRV or IL-2. After 6 days, the frequency of various lymphocyte subsets in these cultured PBMC was determined by flow cytometry: the cells were separated with a magnet-activated cell sorter and the cytolytic activity of the separated populations was determined. When lymphocytes were separated and analysed with FACScan, the following lymphocyte subsets were discriminated: CD6 + CD8(bright) + CD4 - (CTL phenotype), CD6 + CD8(dull) + CD4 + (the fraction containing memory T helper cells), CD6 + CD8 - CD4 + (T helper cell phenotype), CD6 - D8(dull) + CD4 - γδ-T + (γδ-T cell phenotype), CD6 - CD8(dull) + CD4 - γδ-T - (NK phenotype) and CD6 - CD8 - CD4 - γδ-T - or γδ-T +. Flow cytometry analysis demonstrated that PRV stimulation of immune PBMC resulted in the occurrence of more CD6 + CD8 + and CD4 + CD8 + and fewer CD6 - CD8 + and γδ-T + CD8 + lymphocytes than IL-2 stimulation of naive PBMC (P<0·05). It was demonstrated further that killing by PRV-stimulated PBMC was mediated mainly by CD6 + CD8 + T lymphocytes. Killing by IL-2-stimulated PBMC was mediated mainly by CD6 - CD8 + T lymphocytes. These results demonstrate that both natural killing and killing by classical PRV-specific CTL were detected in PRV-immune pigs, whereas IL-2 stimulation of PBMC isolated from naive pigs mainly induced natural killing.
Effects of a porcine reproductive and respiratory syndrome virus infection on the development of the immune response against pseudorabies virus
Bruin, M.G.M. de; Samsom, J.N. ; Voermans, J.J.M. ; Rooij, E.M.A. van; Visser, Y.E. de; Bianchi, A.T.J. - \ 2000
Veterinary Immunology and Immunopathology 76 (2000)1-2. - ISSN 0165-2427 - p. 125 - 135.
The aim of this study was to investigate the effects of a porcine reproductive and respiratory syndrome virus (PRRSV) infection on the development of the immune response after pseudorabies virus (PRV) vaccination in pigs. Pigs were intranasally inoculated with the European PRRSV strain, Lelystad virus ter Huurne, and were vaccinated intramuscularly with PRV 2 weeks later (LV-PRV group). Control pigs were vaccinated with PRV only (PRV group). Eight weeks after PRV vaccination, pigs from both groups were challenged intranasally with wild-type PRV. We measured the lymphoproliferative, and the cytolytic responses to PRV of peripheral blood mononuclear cells (PBMC), isolated from blood samples. In addition, serum samples were examined for antibodies against PRV and LV. One week after PRV vaccination, PBMC proliferated abundantly to PRV in both groups. However, in the LV-PRV group the lymphoproliferative response declined after 1 week, whereas, in the PRV group, the lymphoproliferative response was high for 3 weeks and declined thereafter (P<0.05). After challenge, the lymphoproliferative response was 1 week earlier and was consistently and significantly higher in the PRV group than in the LV-PRV group. The PRV-specific killing was higher at 3 weeks after PRV vaccination and 5 weeks after PRV challenge 19±3 and 24±6%, respectively, in the PRV group, compared to 7±4 and 6±9%, respectively, in the LV-PRV group (P<0.05). However, later after vaccination and challenge the cytolytic response was identical in both groups. The antibody titre against PRV developed equally in both groups. After challenge, no PRV virus was isolated from both groups. From these results we conclude that, although PRRSV infection did cause changes in the time course of the T-lymphocyte response after PRV vaccination, PRRSV infection did not inhibit the development of vaccine-induced protection after PRV.