Passive Hemagglutination Research Articles

Effects of Live Infectious Bursal Disease Vaccines, on Immune Response of Vaccinated Chicks

Aim: Relationship between virus titers of live Infectious Bursal disease (IBD) vaccines and their serum-conversion abilities was studied. Study design and Methodology: Five batches of each, of five IBD vaccine brands used in Nigeria, were tested for virus titers. Each of the vaccine brands was also used to vaccinate a group of fifteen 12-days old chicks to study their serum-conversion abilities. Mean antibody titers of the groups of chicks were plotted, on a graph, against virus titers of the vaccine brands used to vaccinate them. Results: Mean Modified Passive Haemagglutination titers of IBD virus in the vaccines,were:1,065.60±780.03,1,472.00±748.55,2,112.00±1984.00,2,176.00±1920. 00 and 2,585.00±926.92 while mean antibody titers they elicited were, 1,356.80±241.51, 1,280.00±174.88, 448.00±79.25, 998.40±196.27 and 332.80±51.20, respectively. Line of best fit of graph of antibody titers of vaccinated chicks on vaccine titers, showed that reducing titers of the live IBD vaccines improved their immunogenicity. Conclusions: The inverse relationship between virus titers of the vaccines and their Original Research Article British Journal of Medicine & Medical Research, 4(7): 1506-1513, 2014 1507 serum conversion abilities, suggests that, if viral titers of live IBD vaccines are too high, immune-suppression instead of enhancement of immune response may occur.

HBc抗体測定系におけるPHA法（マイセルanti-rHBc）とCLIA法（アーキテクト・HBc II）の比較

We aimed to evaluate the correlation between two methods of the detection of antibody to hepatitis B core antigen (anti-HBc); chemiluminescent immunoassay (CLIA; Architect®Anti-HBc II) and passive hemagglutination assay (PHA; Mycell®anti-rHBc). 249 positive cases and 436 negative cases among 685 employees were determined. The percent agreement between CLIA and PHA was 96.4%. Positive values by PHA were distributed from 26 to 222 fold, while those of CLIA from 1.0 to 26.6 S/CO. High titers more than 10 S/CO by CLIA were equivalent to over 210 fold by PHA. While in low titers of anti-HBc PHA was slightly lower in sensitivity than CLIA, PHA is more quantitative than CLIA in high titers of anti-HBc.

Seroprevalence ofLeptospirosis in Human beings and Animals in Central and NorthKerala

A study was undertaken to assess the prevalence of leptospirosis in animals and man in Central and North Kerala. Five hundred and one sera samples collected from dogs, cattle, pigs, rodents (bandicoots and rats) and human beings were serologically tested for leptospiral antibodies by Microscopic Agglutination Test (MAT) and Passive Haemagglutination Assay (PHA). The MAT detected a prevalence of 36.36 per cent in dogs, 47 per cent in cattle, 23.80 per cent in pigs, 21.42 per cent in rodents and 54.54 per cent in human beings. Passive Haemagglutination Assay detected a prevalence of 50.41 per cent in canine, 23 per cent in bovine, 19.04 per cent in porcine, 26.19 per cent in murine and 42.85 per cent in human sera. The most predominant serovar infecting dogs, pigs and rodents was identified as Leptospira interrogans serovar Pomona. Humans showed maximum prevalence to serovar Australis followed by Pomona while cattle showed the highest prevalence to serovar Hardjo of serogroup Sejroe. High prevalence of leptospiral antibodies in apparently healthy animals like cattle proves the major role played by animals in the dissemination of infection in animal

Diagnosis of scrub typhus: introduction of the immunochromatographic test in Korea

Diagnosis of scrub typhus: introduction of the immunochromatographic test in Korea

Assessment of Antiretroviral Effects of a Synthetic Aluminum-magnesium Silicate

Aim: For an affordable therapy for Human immune-deficiency virus (HIV) infections, antiretroviral effects of a synthetic aluminum-magnesium silicate (AMS) were tested. Materials and Methods: Plasma that tested positive to HIV and the AMS were mixed, on equal volume to weight basis, incubated one hour at room temperature and centrifuged for ten minutes at 3,000 revolutions per minute. These procedures were repeated on each supernatant. HIV titres of the two sets of supernatants and the titres in portions of the plasma, not incubated with the AMS were assessed by direct passive hemagglutination test. Results: Mean HIV titres of the plasma increased from 4.00±1.60 to 14.00±2.00 when incubated with the AMS. Repeating the incubation, reduced mean HIV titres in plasma from 14.00±2.00 to 6.50±1.50 (P=0.024). Conclusion: It was concluded that the AMS has antiretroviral effects and could be an Original Research Article British Journal of Medicine & Medical Research, 4(8): 1672-1679, 2014 1673 inexpensive antiretroviral therapy for regular treatment to reduce high rate of HIV infection among low income groups.

Diagnostics of early forms of syphilis by the chemiluminescence immunoassay method

Goal. Assessment of the diagnostic efficacy of the chemiluminescence immunoassay (CLIA) method for early forms of acquired syphilis. Materials and methods. The authors examined 237 blood serum samples taken from patients suffering from primary (49), secondary (116) and latent early (72) syphilis as well as from 61 healthy blood donors and 20 persons with false-positive results of serological tests for syphilis. Blood serum samples were tested with the use of CLIA, EIA, passive hemagglutination test, immunofluorescence test and microprecipitation test methods. Results. The authors established that the CLIA method used for diagnostics of early forms of acquired syphilis (when the IMMULITE® 2000 Syphilis Screen test system is used) is characterized by high sensitivity (99.6%), specificity (95.1%), diagnostic efficacy (98.3%), predictive value of positive (95.1%) and negative (98.3%) results, which is sufficient for recommending this method as the screening method for diagnostics of syphilis to be used in large diagnostic centers. The CLIA method may also be used to confirm the diagnosis of syphilis. Conclusion. Based on these results, the authors developed a reverse algorithm for diagnostics of early forms of acquired syphilis beginning with the use of the CLIA method with further use of the nontreponemal method (microprecipitation reaction or other nontreponemal method).

Isolation and Identification of Pasteurella multocida from Chicken for the Preparation of Oil Adjuvanted Vaccine

The research work was performed for the isolation and identification of Pasteurella multocida from field cases, preparation of oil adjuvanted vaccine from isolated strain and determination of its efficacy. Samples were collected from suspected dead birds of three poultry farms of Bangladesh (Code name: M and R). The P. multocida isolates were Gram negative, non-motile, non- spore forming rod occurring singly or pairs and occasionally as chains or filaments. Biochemically P. multocida ferment basic sugar and consistently produced acid except from maltose and lactose. After isolation formalin killed oil adjuvanted Fowl cholera vaccine was prepared in Laboratory of the Department of Microbiology and Hygiene, BAU and this experimental vaccine (3.2x108 CFU/ml) was administered in nine weeks old White Leg Horn chickens at the different dose rate through intramuscular (IM) route in each selected group A (1ml alum precipitated vaccine), B (0.5ml alum precipitated vaccine), C (1ml oil adjuvanted vaccine) and D (0.5ml oil adjuvanted vaccine). Pre-vaccinated sera were collected from all groups of birds. The mean of Passive Hemagglutination (PHA) titers of post-vaccination were 51±17.8, 76.8±17, 89.6±17, and 115±17.81 in group A, B, C and D respectively which consist of 5 birds in each. The vaccine produced better immune response when boostering with the similar dose and route at 15 days after primary vaccination. The mean PHA titers were higher at group D than other groups after boostering. Challenge infection was conducted on all the vaccinated and control group (n=5) of birds after 15 days of vaccination which protect 93.75% of birds and the PHA titers from different groups analyzed to determine the protective capacity of vaccinated chickens against challenge exposure. It was demonstrated that experimental oil adjuvanted fowl cholera vaccine with 0.5ml dose produce higher immune response against challenge infection and found to be safe. Microbes and Health, June 2013, 2(1): 1-4DOI: http://dx.doi.org/10.3329/mh.v2i1.17253

Epidemiological and genetic analysis of human group C rotaviruses isolated from outbreaks of acute gastroenteritis in Yokohama, Japan, between 2006 and 2012

Group C rotavirus (GCRV) infection has been described in several parts of the world, predominantly as sporadic cases of acute gastroenteritis. Little is known about the yearly changes in the GCRV strains from diarrheal outbreaks. Stool samples collected from outbreaks of acute gastroenteritis in Yokohama, Japan, between 2006 and 2012 that were negative for norovirus, sapovirus, and group A rotavirus, were screened for GCRV using a reverse passive hemagglutination method. The GCRV strains were characterized by nucleotide sequence and phylogenetic analysis of their VP6, VP7, VP4, and NSP4 genes. Samples from nine of 735 outbreaks in Yokohama (1%) contained GCRV, and eight of these outbreaks occurred in primary schools. The nucleotide sequences of the strains detected in this study were more closely related to Asian strains than to those from other regions of the world. The nucleotide sequences of the VP7 gene in these nine strains differed, and yearly changes were observed in the amino acid sequences of the VP4 genes. Phylogenetic trees constructed using the nucleotide sequences of the VP6, VP7, VP4, and NSP4 genes showed that sublineage S1 has divided into S1-1 and S1-2 in the VP4 gene only. Our results confirm that the prevalent strains of GCRV change yearly in Yokohama. This is the first study to demonstrate GCRV-associated gastroenteritis outbreaks in Yokohama, Japan.

Horizontal transmission of bovine leukemia virus from lymphocytotic cattle, and beneficial effects of insect vector control

Bovine leukaemia virus (BLV) causes enzootic bovine leukosis (EBL) in cattle and represents a serious problem in Japanese meat and dairy industries (Ministry of Agriculture, Forestry and Fisheries). BLV can...

The role of alloantibodies against human platelet antigen‐15 in multiply platelet transfused patients

Several studies have documented the role of antibodies against human platelet (PLT) antigen (HPA)-15 in alloimmune-mediated thrombocytopenia including neonatal alloimmune thrombocytopenia, PLT transfusion refractoriness (PTR), and posttransfusion purpura in Caucasian persons. However, the relevance of anti-HPA-15 in PTR among the Japanese population is still unclear. The sera of 305 multiply PLT transfused (MPT) patients, previously investigated for the presence of human leukocyte antigen (HLA) and HPA antibodies by mixed passive hemagglutination, were reexamined for the presence of HPA-15 alloantibodies, using the monoclonal antibody-specific immobilization of PLT antigens (MAIPA) technique. Among the 305 MPT samples, antibodies against HPA-15 alloantigen was detected in seven (2.3%), two (0.66%) being anti-HPA-15a and five (1.64%) being anti-HPA-15b. Additionally, one case of CD109 panreactive antibody was found (0.33%). Among them, one aplastic anemia patient with blood group O developed multispecific anti-HLA and anti-HPA-15b alloantibody after MPTs. However, transfusion with HLA-matched PLTs of blood group AB did not result in adequate PLT count increment. Analysis of the possible influence of immune anti-A and anti-B by the MAIPA assay resulted negative, indicating that anti-HPA-15b is responsible for the refractory state in this patient. In this study, we found alloimmunization against HPA-15a and -15b in Japanese populations and demonstrated the relevance of these antibodies in a patient with PTR.

Extraction of calicomacropeptide protein from cheese whey and its use as an antibacterial agent against Escherichia coli and Staphylococcus aureus in children.

This study focused on the extracted of protein Glycomacropeptide of soft white cheese whey and factory using rennet (chymosin) and studying of its effect outside the body's animals in vetro and within the body of the animal in vivo, the results were as follows: pathological bacteria antigens used with Glycomacropeptide in passive haemagglutination assay and showed that agglutination was 1:256 with LPS isolated from bacteria E. coli. The passive haemagglutination assay also showed that agglutination was 1:64 with LPS isolated from bacteria Staph. aureus Glycomacropeptide protein proved the inhibition activity the outsideof the animal's body (in vitro) against bacterial isolates of E. coli and , which causes diarrhea and inflammatory intestine disease and Staph. aureus bacteria in children by using Nutreint Broth media and using a Spectrophotometer and different concentrations (0.1, 0.6, 1.1, 6.3) mg / ml had a higher inhibition concentration of 6.3 followed by 1.1. Glycomacropeptide protein proved effectiveness inhibitory, within the body of mice (In vivo) against bacteria E. coli and Staph. aureus by studying their effect on red blood cells and white blood cell as it worked to increase

IMMUNE RESPONSE CAPABILITY OF `SHUVRA’ CHICKEN

The study was carried out to determine the humoral immune response to Newcastle Disease Virus (NDV) and Bangladesh Agricultural University Fowl cholera (BAUFC) vaccines in Shuvra chicken, a newly develop chicken strain by BLRI (Bangladesh Livestock Research Institute). Ten Shuvra chickens were vaccinated with Baby Chick Ranikhet Disease Vaccine (BCRDV) at day 7 through intra ocular route (i/o) and with Ranikhet Disease Vaccine (RDV) at day 35 through intramuscular (i/m) route. Vaccine induced serum Haemagglunination Inhibition (HI) antibodies were measured by HI test. Two weeks after final immunization all vaccinated and control Shuvra chickens were challenged with virulent field isolates of NDV where all the vaccinated birds survived without showing any typical signs of NDV during the period of ten days observation period and all the control chickens died. Another 10 Shuvra were vaccinated twice with BAUFC vaccine through intramuscular route at day 42 and 70, and 10 Shuvra chickens were kept as unvaccinated control. This vaccine also induced significantly higher level of antibody titre as determined by Passive Haemagglutination (PHA) test. Vaccinated chickens showed significantly higher survival (80%) following challenge with virulent fowl cholera isolate and all the control birds died within 10 days of observation period. DOI: http://dx.doi.org/10.3329/bjvm.v10i1-2.15639Bangl. J. Vet. Med. (2012). 10 (1&2): 1-7

22 Study the Immune Response of Conjunctival and Subcutaneous Vaccination of Goats with RB51 Vaccine for Controlling Brucellosis

This study was conducted to evaluate the efficacy of RB51 vaccine in immunization of goats against brucellosis although it is a specific vaccine for cattle, fifteen pregnant and non-pregnant goats were divided into three groups, 5 goats were injected subcutaneously(S/C) with 2 mls of RB51 vaccine which contain 4 × 108 CFU , 5 goats were vaccinated through conjunctival route (C/J) with 0.2 ml of RB51 which contain 4 × 108 CFU , and the last 5 goats were injected with PBS and kept as control group. It has been ascertained that no abortion occurred in the vaccinated animals except one case of a weak kid was born in S/C vaccinated group. Humeral immune response for the vaccinated animals measured by serological test (Rose Bengal and Passive hemagglutination tests) every two weeks, while the cellular immune response measured by brucellin test at the 6th week. Passive haemaglutination test (PHA) was positive and the antibodies were increased significantly (P<0.05) at the 2nd week to reach 10.4±2.4 and 6.4±0.9 in S/C and C/J routes respectively, and increased significantly (P<0.05) at 8th week to reach 38.4±6.4 and 22.4±3.9 in S/C and C/J routes respectively, and decreased significantly at 12th week which reach 9.6±1.6 to 6.4±0.9. Brucellin from RB51 strain prepared to be used as antigen in the PHA test and also in skin test to determine delayed type hypersensitivity, serial dilutions of RB51 brucellin had been done to confer the optimal concentration in skin test that did not induce toxicity for mice 40µg was the optimal concentration that has been given to goats. In goats the results indicated that the S/C group showed a high delayed type hypersensitivity compared with C/J group and the good skin reactions was increased to reach the maximum at 48 hrs post brucellin injection (PBI), when the erythema diameter reached 7.1±0.09mm and 5.4±0.3mm in S/C and C/J groups respectively and skin thickness was2.9±0.1 mm and 2.1±0.2 mm in S/C and C/J groups respectively. These results showed that immunized animals expressed cellular and humeral immune response examined by DTH and PHA. Concluded that the RB51 vaccine gave good level of immunization in goats and it can be considered as alternative vaccine against heterogonous Brucella spp.

English

The commercial production of purified tetanus toxoid mainly depends on the effective separation of the bacterial toxin and toxoid from large volumes of fermentation broth of Clostridium tetani (Harvard 49205) vaccine strain. Tangential flow or cross-flow filtration system was used as rapid drive in the processing of immunobiological assays of tetanus toxin. Tetanus toxoid was prepared by detoxifying the culture filtrates of C. tetani and further purified by ultrafiltration, salt fractionation and adsorption onto aluminium phosphate. Present study deals with the separation of tetanus toxins using a microporous membrane (0.22 µm) and concentration of tetanus toxoids using an ultrafiltration membrane (30 kDa, NMWL pore size) with operational variables like average trans-membrane pressure (ATP), cross flow rate, flux. Under the best conditions, >96% recovery was achieved. Additionally, potency control of 10 batches of tetanus toxoid, prepared from the filtered toxins/toxoid lots by microporous tangential flow filtration system, was evaluated by in vitro passive haemagglutination (PHA) assay and the results obtained in the in vitro PHA were compared with in vivo toxin neutralization (TN) test. An excellent correlation between in vitro test and in vivo TN test was observed by Spearman’s correlation coefficient. It reveals that the process development in which employing available equipment and the in vitro PHA is a promising alternative to the toxic TN test in the potency assay of tetanus vaccine. Key words: Tetanus toxin, Seitz filtration, tangential flow filtration, microfiltration module, flux, tetanus toxoid, immunogenicity test.

Profil épidémiologique de 290 cas d’échinococcose kystique humaine diagnostiqués au CHU Mustapha d’Alger (2006 à 2011)

The aim of the studyThis study reports a series of 290 cases of hydatidosis confirmed by the surgery and/or the imagery with a positive immuno-diagnosis collected between 1st January 2006 and 31 March 2011 at parasitology-mycology laboratory of hospital university center of Mustapha of Algiers. Our aim is to specify, through the listed cases, the epidemiological aspects of this affection and compared with those obtained in two previous Algerian epidemiological investigations carried out, between 1963–1964 and 1966–1975. Patients and methodsIt is a retrospective (2006–2008) and prospective (2008–2011) study. The parasitological diagnosis was carried out by the direct macroscopic and/or microscopic identification of the parasite and indirect diagnosis based on four techniques: passive hemagglutination, Elisa IgG “Echinococcus granulosus”, Western Blot IgG “Echinococcus” and electrophoresis. ResultsThe study shows that this affection is still prerogative of the young adult. It bring out also in this study that the child of school age (ten years), in particular the boy, pays a heavy tribute. At the child, the preferential pulmonary seat of the hydatic disease is not devoid of risk. At adult, this parasitic disease mainly affect the active woman. ConclusionGenerally, the epidemiological and clinical characteristics join the endemic countries data and confirmed the row of our country among them. The transmission seems as strong as in the past, in spite of a much better social educational level.

Immune response and protective potential following vaccination against Newcastle disease virus and fowl cholera in Naked neck chickens

Humoral immune responses to Newcastle Disease Virus (NDV) and Bangladesh Agricultural University (BAU) Fowl cholera (BAUFC) vaccines were evaluated in naked neck chickens (NNC). Ten birds were vaccinated with Baby Chick Ranikhet Disease Virus (BCRDV) at Day 7 through intra-ocular route and with Ranikhet Disease Virus (RDV) at day 35 of age through intramuscular route. Serum antibodies were measured by Haemagglutination Inhibition test. Two weeks after final immunization all birds were challenged with virulent field isolate of NDV where all vaccinated birds survived without illness during ten days, and all ten control birds died. Ten birds were vaccinated with BAUFC vaccine at Day 42 and 70 according to the Manufacturer’s instruction, which induced detectable levels of antibody titre as determined by Passive Haemagglutination Assay (PHA) test. Eight vaccinated birds survived following challenge with virulent fowl cholera isolate two weeks after final vaccination and all ten control birds died. DOI: http://dx.doi.org/10.3329/bvet.v29i2.14342 Bangl. vet. 2012. Vol. 29, No. 2, 49-55

English

A survey was conducted to investigate the prevalence of Peste des petits ruminants (PPR) and sheep pox (SP) as the most economically important viral diseases of small ruminants in Marawi province at Northern state, Sudan. A total of 254 sera samples (164 ovine and 90 caprine) were collected from various localities in Marawi province during May, 2008. All collected sera were examined for PPR antibodies using competitive enzyme-linked immunoabsorbent assay (cELISA) and for SP antibodies using passive Haemagglutination test. 42 (25.6%) ovine and 17 (18.8%) caprine sera were positive for PPR antibodies while 51 (31%) ovine and 34 (37.7%) caprine sera were positive for sheep pox antibodies.   Keywords: PPR, Sheep pox, cELISA, PHA, Sudan.

Investigation on the Efficacy of a Killed Salmonella pullorum Vaccine

This study was carried out to determine the efficacy of a formalin-killed alum-precipitated Salmonella pullorum vaccine prepared by the Livestock and Poultry Vaccine Research and Production Centre (LPVRPC), BAU, Mymensingh, Bangladesh. Immunization with this vaccine induced serum antibody titers that peaked in 2-week following both primary and booster vaccination (P<0.05), and started to decline following 4-week of both vaccinations. Both primary and booster vaccination induced detectable antibody responses that were able to react with whole cells S. pullorum as determined by passive haemagglutination test (PHA). Both vaccinated chicken and mice showed maximal resistance following challenge with a virulent isolate of S. pullorum (P<0.01). In differential leukocyte counts in mice, a significant increase of lymphocytes was observed after primary immunization (P<0.01). Sera from vaccinated chickens conferred superior protection over naive chickens from lethal challenge with S. pullorum (P<0.01). Finally, this result indicates that S. pullorum vaccine is effective for controlling pullorum disease and antibody is crucial for protection.DOI: http://dx.doi.org/10.3329/mh.v1i1.13707 Microbes and Health Vol.1(1) June 2012 pp.14-18

Immunological evaluation of Vi capsular polysaccharide of Salmonella enterica subsp. Typhi vaccine by serum bactericidal assay

Salmonella enterica subsp. Typhi (S. Typhi) Vi antigen capsular polysaccharide (Vi-CPS) is a licensed vaccine against typhoid fever. As there is no animal model for S. Typhi fever to evaluate the protective efficacy of the Vi-CPS vaccine, a serum bactericidal assay (SBA) is the recommended 'gold standard' to evaluate its potency. Vi-CPS was extracted from S. Typhi Ty6S (CSBPI-B191) using a modified Gotschlich method. Purified Vi-CPS (50 µg) was injected intramuscularly into three groups of five rabbits; group 2 received an additional booster dose of 50 µg Vi-CPS on day 15 and group 3 received two additional boosters on days 15 and 30. The sera obtained from each group were tested by SBA on days 0, 15, 30 and 45. The anti-Vi-CPS titres for groups 1, 2 and 3 on days 15, 30 and 45 were 4, 16 and 16; 4, 32 and 32; and 16, 64 and 64, respectively. Thus, Vi-CPS was shown to be a potent immunogen, as even one dose could induce an efficient bactericidal effect against S. Typhi. Although Vi-CPS is a reliable vaccine, sometimes depolymerization during purification can affect its potency, which can be resolved through a potency test. As the passive haemagglutination test recommended by the World Health Organization does not indicate vaccine potency, we recommend using an SBA to evaluate the bactericidal ability of Vi-CPS.

Evaluation sur le terrain du transfert des anticorps maternels contre l'encéphalomyélite aviaire dans des élevages de poulets du sud-ouest du Nigeria

L’encéphalomyélite aviaire (AE) est contrôlée par l’apport d’un niveau suffisant d’anticorps maternels chez les poussins. Des épidémies persistantes, malgré la vaccination des reproducteurs dans les élevages de poulets du sud-ouest du Nigeria, ont incité les auteurs à évaluer les taux d’anticorps contre le virus AE dans des troupeaux de reproducteurs et de leur progéniture. Cinq troupeaux de reproducteurs de poulets prévaccinés (troupeaux A, B, C, D et E) ont été sélectionnés à Ibadan, Etat d’Oyo, et Mowe, Etat d’Ogun. Des échantillons sanguins ont été prélevés sur quinze reproducteurs de chaque troupeau ainsi que sur leurs poussins âgés de 1, 7 et 14 jours, et les sérums ont été soumis à l’épreuve d’hémagglutination passive. La variation des titres, la moyenne géométrique des titres (MGT) et le taux de transfert des anticorps maternels ont été déterminés pour chaque troupeau. La MGT a varié entre 3,3 ± 0,09 et 4,8 ± 0,14 dans les troupeaux de reproducteurs, 0,8 ± 0,09 et 2,4 ± 0,21 chez les poussins âgés d’un jour, et 2,8 ± 0,15 et 3,9 ± 0,06 chez les poussins âgés de 7 jours. Les valeurs les plus élevées toutes catégories confondues ont été observées dans le troupeau de poulets de chair D. La MGT a varié entre 1,4 ± 0,18 et 2,3 ± 0,17 chez les 14 poussins âgés de 14 jours, et la valeur la plus élevée a été obtenue dans le troupeau de poulets de chair C. Dans l’ensemble, la MGT des poussins d’un jour a baissé significativement (p < 0,05) par rapport à celle des reproducteurs. Les taux de transfert des anticorps maternels ont été plus élevés dans les troupeaux de poulets de chair C et D avec respectivement 50 et 40,9 p. 100, alors que ceux des troupeaux de poulettes A, B et E ont été respectivement de 24,2, 19,5 et 19,5 p. 100. Cette étude a montré que le transfert des anticorps maternels était faible six mois après la vaccination, en particulier dans les troupeaux de poulettes, se traduisant par des titres d’anticorps faibles ou indétectables chez les poussins âgés d’un jour. Une modification du calendrier de vaccination est donc recommandée.