Non-vaccinated Dams Research Articles

Colostral transmission of BTV-8 antibodies from dairy cows six years after vaccination

Bluetongue virus (BTV) antibodies were analysed in 27 Swiss calves born in 2016 at the age of 16–19 days using competitive enzyme-linked-immunosorbent-assay (cELISA) and virus neutralization test (VNT) (animal trial permission number: 75684). Obligatory documentation proved that 15 of 27 dams were BTV-8 vaccinated once or three times in 2008–2010. The offsprings of the non-vaccinated dams were seronegative. Two of three calves and 11 of 12 calves descending from dams who had been vaccinated one or three times, respectively, had BTV specific serum antibodies. As Switzerland is considered BTV-free from 2010 to 2016, it is likely that BTV-8 antibodies were transferred via colostrum. Furthermore, we confirmed neutralizing cross-reactivity of BTV-8 with BTV-4 antibodies as 5 samples positive for BTV-8 were also reactive with BTV-4 antibodies.

Comparison of cytokine profiles in peripheral blood mononuclear cells between piglets born from Porcine circovirus 2 vaccinated and non-vaccinated sows

This study was aimed to evaluate the effect of Porcine circovirus 2 (PCV2) sow vaccination on cell-mediated immune responses in sows and their progeny. At 7 weeks before farrowing, fifteen PCV2 PCR negative pregnant sows with medium-low antibody values were selected and randomly distributed in two groups according to the antibody levels. Seven sows were vaccinated with a commercial PCV2 vaccine and eight were injected with phosphate-buffered saline at 6 and 3 weeks before farrowing. Blood samples were taken from sows and their piglets (n = 90) during the study duration. PCV2 DNA and antibodies were tested in sera, and cytokine (IFN-α, IFN-γ, IL-12p40, TNF-α, IL-1β, IL-8, IL-4, IL-6 and IL-10) levels were assessed in supernatant from cultured peripheral blood mononuclear cells. All sows and piglets were negative by PCV2 PCR throughout the study. Significantly higher PCV2 antibody levels were detected in vaccinated sows after vaccination and in their offspring after colostrum ingestion compared to the non-vaccinated counterparts. Vaccinated sows did not show significant differences in cytokine secretion levels at farrowing compared to unvaccinated dams. In contrast, piglets from vaccinated sows had significantly higher levels of cytokines linked to Th1 memory cells (IFN-γ and TNF-α) in comparison to the ones from non-vaccinated dams. In conclusion, PCV2 sow vaccination, apart from triggering a humoral immunity response in sows and their progeny, might be associated to an increased transfer of cell-mediated immunity from the dam to the piglet.

Efficacity and safety of TOXO KO vaccine to prevent ocular toxoplasmosis in congenital murine model

PurposeToxoplasmosis is a worldwide zoonotic disease caused by the protozoa Toxoplasma gondii and is a major cause of abortions but also of ocular lesions. Thus, ocular toxoplasmosis is a major health issue in certain parts of the world, especially in South America and Africa.MethodsWe have studied the efficacy of a live attenuated strain of T. gondii (i.e. Toxo mic1‐3 KO mutant) as a vaccine against ocular toxoplasmosis in a congenital toxoplasmosis model in mice. Mice were vaccinated with Toxo mic1‐3 KO strain, mated and infected during pregnancy. Nonvaccinated mice infected at mid gestation with T. gondii were used as control. One month after delivery, pups were sacrificed and ocular fundus, cytokine production in intra‐camerular tissue and cysts formation in eye and in brain were analysed.ResultsWe have demonstrated that: Retinal T. gondii cysts were detected in 71% of pups born to nonvaccinated dams (2.54 ± 4.10). A significantly smaller number of cysts in retinal tissue was seen in pups born to vaccinated dams 0.56 ± 1.18 (>86% reduction in cysts in ocular tissue). Clinical signs of ocular infection were detected in 73.2% of pups born to non vaccinated dams against 19% of pups born to vaccinated dams.ConclusionsIn conclusion, Toxo mic1‐3 KO is an effective vaccine against ocular toxoplasmosis in a congenital mice model. This strain could be a promizing vaccine.

Coxiella burnetii antibody dynamics in heifers born to vaccinated versus non-vaccinated dams in a chronically infected dairy herd.

This study was designed to compare Coxiella burnetii antibody dynamics in heifers born to vaccinated or non-vaccinated dams in a single high-producing dairy herd chronically infected with the bacterium. Antibody dynamics were examined from birth to the postpartum period in replacement heifers (n = 14) born to non-vaccinated dams (n = 7) or to dams that had been vaccinated on gestation days 171-177 (n = 7) and 192-198. Samples of blood, milk, faeces, vaginal fluid, colostrum and cotyledons (the latter two only at parturition) were obtained in the dams over the period from gestation days 171-177 to postpartum days 91-97. Blood samples were used to detect antibodies against C. burnetii and remaining samples for PCR identification of the bacterium. In their calves/heifers, blood samples for antibody determinations were collected from birth to postpartum at the time points 1-7 and 22-28 days and 3, 6 and 12 months of age; 90-96 and 210-216 days of gestation; and 22-28 days postpartum. All calves were born seronegative for C. burnetii. Irrespective of the shedding status of their mothers (7 were C. burnetii shedders), seroconversion occurred after colostrum intake in all calves born to seropositive cows (n = 9) and in two of three vaccinated seronegative dams. Thereafter antibody titres gradually declined and by 6 months of age all calves were seronegative. Seronegativity persisted until their first postpartum period. These findings indicate that cows vaccinated during advanced pregnancy transfer immunity to their calves via the colostrum. Maternal C. burnetii antibodies in calves persisted for three months in calves born both to seronegative vaccinated and seropositive dams.

Strategic control of acute diarrhea of newborn calves.

Economic performance of beef cattle operations can be severely hampered by acute calfhood diarrhea. Accordingly, a study was conducted at Bbalitvet to identify the causal agents, reduce clinical incidence, and increase body weight gain of newborn calves. One potential control is application of suitable vaccines to pregnant cows. The study was begun by identifying cases of diarrhea followed by isolation and identification of the causal agents in 12 beef cattle farms in West Java. A field trial was then designed for controlling calf diarrhea in such farms. Inactive vaccines Ecoli-Closvak polivalen were administered to pregnant cows to increase specific resistance of the newborn calves. At 2 months prepartum, 12 pregnant cows were assigned either to a vaccination or a placebo group, with a booster vaccination 3 weeks prior to parturition. Strict hygenic management was provided to both groups, and all calves were provided adequately with colostrum. Subjects were observed for 5 months, starting from the time of initial vaccination until the calves were 3 months of age. In the initial farm surveys, entero-pathogenic bacteria such as Escherichia coli serotype K99 and Clostridium perfringens type A and C were isolated and identified in fecal samples from 4 beef cattle farms in 3 districts (Garut, Tasikmalaya, Ciamis) and 2 beef cattle farms in 2 districts (Tasikmalaya and Ciamis) of West Java. In the vaccination trial, good immune responses to E. coli and C. perfringens alpha toxin measured by ELISA were observed. Application of effective control of calf diarrhea including vaccination and good livestock management showed good results. No death or signs of diarrhea were found in the new born calves up to 3 months of age. The rate of body weight gain was significantly higher in calves of vaccinated dams than in calves of non-vaccinated dams. Key W ord s : Strategic control, Calf diarrhea

DINÁMICA DE LA INFECCIÓN CON Mycoplasma hyopneumoniae EN PORCINOS PROVENIENTES DE MADRES CON Y SIN ANTECEDENTES DE INMUNIZACIÓN

The aim of the study was to determine the time of infection with Mycoplasma hyopneumoniae in 240 piglets of vaccinated and non vaccinated sows from a positive farm with an all-in/all-out (AIAO) system, located in the Chillón valley, Lima. The study was conducted during autumn and winter 2003. One group of sows was vaccinated with 2 ml of a M. hyopneumoniae commercial bacterin at 85 days of gestation while the other group remained unvaccinated. Two groups of 120 piglets each were established according to their dams’ status of immunity. Blood samples were collected from piglets at various times during the production period (weaning till slaughter) for measuring antibodies against M. hyopneumoniae using an ELISA indirect assay. The 66.6 (74/112) and 85.6% (101/118) of piglets from the vaccinated and non-vaccinated dams, respectively, were seroreactive throughout the period of the study. The results indicated that the time of infection occurred in both groups at approximately 10 weeks of age, and without significant differences between groups (p>0.05). Time of infection occurred concomitantly with the stress caused by the relocation of piglets from nursery to growth-finishing corrals

EVALUACIÓN DE UNA BACTERINA DE DOSIS ÚNICA CONTRA Mycoplasma hyopnemoniae EN PORCINOS DE MADRES NO VACUNADAS.

The effect of a single dose bacterin against Mycoplasma hyopnemoniae on body weight gain, antibody titers, and degree of lung lesions in piglets from non-vaccinated dams reared in a pig farm with history of mycoplasmosis was evaluated. A total of 60 piglets of both sexes were distributed in a vaccinated and a control group. The bacterin was applied at 6 weeks of age. The frequency of seropositive animals and the antibody titers against M. hyopnemoniae were determined using serum samples collected at 3, 6, 10, 12, 16, and 21 weeks of age. Body weight gain (g/day) was calculated from body weight at weaning (19 days) and at slaughter (140 days). Antibody levels were significantly higher at 10 and 13 weeks (p<0.05) in the vaccinated group, but similar from week 16 onwards, possibly due to the natural infection process in the control group. The level of lung lesions and number of affected animals was lower in the vaccinated group. It is concluded that the bacterin of a single dose had a positive effect against M. hyopnemoniae improving body weight gain.

Protective immunization in mice against group B streptococci using encapsulated C5a peptidase

The purpose of the study was to test whether C5a peptidase encapsulated within a biodegradable polymer can act as a vaccine and elicit an immune response to prevent group B streptococci (GBS) infection in mice and provide protection to pups. C5a peptidase was encapsulated in semipermeable microspheres of poly(lactide-co-glycolide). Female ICR mice were immunized with encapsulated C5a peptidase, free C5a peptidase, or empty microparticles. Booster doses were given at days 21 and 42. Antibody responses were measured by enzyme-linked immunosorbent assay. Challenge with GBS type III was performed 4 days after the final booster in the vaginal vault of adult mice and intraperitoneally 48 hours after the birth for pups. Encapsulated C5a peptidase elicited a systemic immunoglobulin (Ig) G antibody response after intramuscular and intranasal administration. Unencapsulated C5a peptidase elicited a smaller systemic response. In addition to the strong IgG response, a secretory IgA response was observed in the vaginal mucosa after intranasal vaccination. No evidence of GBS colonization was found in vaccinated mice. Eighty-seven percent and 81% of the pups from intramuscularly and intranasally vaccinated dams survived a 90% lethal dose (LD90) GBS challenge vs 9% born to nonvaccinated dams. Encapsulated C5a peptidase elicited significant immune responses and protection against GBS challenge. C5a peptidase microsphere encapsulation has potential as a GBS vaccine.

Prime-boost vaccine regimen confers protective immunity to human-derived enterotoxigenic Escherichia coli

Development of effective vaccines against diarrhea caused by enterotoxigenic Escherichia coli (ETEC) strains is still a priority for those living at or traveling to endemic regions. In this work, we evaluated the protective role of an anti-ETEC vaccine regimen based on parenteral priming with a DNA vaccine, pRECFA, followed by oral boosting with a recombinant attenuated Salmonella Typhimurium vaccine strain, HG3, both encoding the same antigen, the structural subunit (CfaB) of the ETEC CFA/I fimbriae. The DNA-priming Salmonella-boosting protocol enhanced both murine anti-CfaB serum IgG and fecal IgA antibody responses and increased the ability of serum antibodies to inhibit the adhesive properties of the CFA/I fimbriae expressed by live bacteria, as compared to mice immunized with only one vaccine type. Addition of a mucosal adjuvant (LT R192G) to the Salmonella vaccine strain further enhanced the synergic effects of the vaccine regimen on the induced CfaB-specific antibody responses. DBA/2 dams submitted to the prime-boost regimen transferred complete passive protection to suckling neonates challenged with a virulent ETEC strain. Detection of milk anti-CfaB IgA antibodies and protection conferred by vaccinated dams to neonates born from non-vaccinated dams indicated that secretion of antigen-specific IgA is the immune response induced by the protective vaccine regimen. These results demonstrate that priming with a DNA vaccine and boosting with a Salmonella strain enhances both quantitatively and qualitatively the antibody responses to the CfaB antigen and represents an alternative for either active or passive immunization approach to ETEC-associated diarrhea.

Maternal antibody passively transferred interferes with rabies vaccination in hamsters

Transference and interference of maternal immunity to offspring after rabies vaccination were studied in hamsters. Females were vaccinated or not before mating and offspring were vaccinated at the age of 7, 14, 21 and 30 days. Other pups were maintained as controls. Thirty days after vaccination pups were challenged intracerebrally with CVS virus. Mouse neutralization tests were used to verify antibody titers. Mortality of 97.0, 76.9, 60.9 and 24.0% was observed in pups vaccinated at 7, 14, 21 and 30 days respectively, born from vaccinated dams, while in pups from non-vaccinated dams, mortality was 51.4, 28.6, 8.7 and 0.0%. Statistically significant associations were found between mortality and age at vaccination, by simple linear regression with y=−3.1169 x+120.8 ( p=0.008; r 2=0.98) for litters vaccinated and born from vaccinated dams and y=−2.2541 x+62.7495 ( p=0.03; r 2=0.93) for pups vaccinated and born from non-vaccinated dams. Immunological response to vaccination in pups born from vaccinated mothers was delayed 11 days, when compared to that observed in pups of non-vaccinated mothers.

Congenital toxoplasmosis in the Balb/c mouse: prevention of vertical disease transmission and fetal death by vaccination

Vertical disease transmission only occurs in Balb/c mice infected with Toxoplasma gondii for the first time during pregnancy. This is similar to the situation in humans, where a previous infection with T. gondii tends to give life-long immunity against reinfection and fetal disease transmission. The Balb/c mouse therefore provides a suitable model to study the effectiveness of T. gondii vaccine candidates. A soluble tachyzoite antigen (STAg) preparation was used to vaccinate female Balb/c mice. STAg was inoculated subcutaneously into Balb/c mice in phosphate-buffered saline (PBS), emulsified in Freund's complete adjuvant (FCA), or entrapped within non-ionic surfactant vesicles (NISV). While all inocula induced cellular immunity as measured by parasite-specific spleen cell proliferation in vitro, the highest mean proliferative values were observed in spleens from mice where NISV had been used as the adjuvant and the lowest values were observed where FCA had been used. More importantly, cultures from the NISV/STAg vaccinated mice produced significantly more γ-interferon than the other experimental groups. This vaccine formulation was therefore identified as that most likely to induce protective immunity against toxoplasmosis. Mice were inoculated subcutaneously with either NISV/STAg or STAg in PBS 4 and 2 weeks before mating and infected orally with 20 tissue cysts of T. gondii on day 12 of pregnancy. The incidence of fetal infection and death in these mice and non-vaccinated infected dams was compared. Of 84 pups born to 14 non-vaccinated dams 45 were viable, of which 18 were found to be infected on reaching maturity. All 67 of the pups born to the 11 dams vaccinated with STAg/NISV survived into maturity, of which a mere nine were infected. These studies emphasize that, given appropriate antigen and adjuvant preparations for vaccination, sufficient immunity can be generated in Balb/c dams to severely limit the likelihood of T. gondii-induced abortion and congenital disease.

The mechanism of protection of infant mice from intestinal colonisation with Campylobacter jejuni.

BALB/c mice, vaccinated intraperitoneally with a heat-killed (62 degrees C) suspension of Campylobacter jejuni before mating, completely protect c. 90% of their own infants from intestinal colonisation. This protection has now been investigated further in fostering experiments. Fostering by vaccinated dams within the first 24 h of life prevented intestinal colonisation in 50% of infants from non-vaccinated dams, and reduced colonisation in a further 25%. Infants from vaccinated dams, even if allowed to receive their own mothers' colostrum and milk, became susceptible to challenge when subsequently fostered by non-vaccinated dams. Immunity in experimentally infected infant mice depended upon the consumption of immune milk at and after the time of challenge. High concentrations of IgG antibodies specific for C. jejuni were found in the serum and mammary secretion of vaccinated dams, but there was very little specific IgA antibody.

Evaluation of procholeragenoid against experimental colibacillosis in piglets of vaccinated dams.

A toxoid prepared from the toxin of Vibrio cholera was adjuvanted with aluminium hydroxide and used for immunisation of pregnant gilts. Litters of these and of non-vaccinates were experimentally challenged with Escherichia coli producing either heat labile and heat stable (LT and ST) enterotoxins or ST enterotoxin only. Both the challenge strains of E coli produced high rates of mortality (64 and 68 per cent) and morbidity (80 and 100 per cent) in litters of non-vaccinated dams. Statistically highly significant protection against the LT/ST enterotoxin producing strain of E coli was obtained accompanied by the absence of colonisation of the small intestine by the pathogen. No protection against the ST enterotoxin producing strain was found. It is suggested that this vaccine would not confer passive protection to piglets against K99 and 987-positive E coli which usually produce ST enterotoxin only.

Prevention of experimentally induced enteric colibacillosis in newborn calves.

Severe enteric colibacillosis, characterized by profuse watery diarrhea, dehydration, apathy, hypothermia, and inability to stand, was produced in seven of eight newborn, colostrum-fed calves from nonvaccinated dams after oral challenge of calves with 10(11) viable cells of Escherichia coli strain B44. Twenty-nine of 32 calves from dams vaccinated with various preparations of E. coli strain B44 were protected against severe enteric colibacillosis after oral challenge. Calves were protected if the dams received two subcutaneous vaccinations prior to calving. Calves also were protected if the dams were given a homologous vaccine of live or killed whole cells or a broth culture supernatant vaccine via the subcutaneous and intramammary routes 1 year earlier. Nineteen of the 29 protected calves had a transient diarrhea.

Experimental Neonatal Diarrhoea Caused By An Enteropathogenic Strain Of Escherichia Coli In Piglets: A Study Of The Disease And The Effect Of Vaccinating The Dam

Summary Experimental neonatal diarrhoea (E.N.D.) was produced in litters of piglets derived from gilts after oral administration at birth of a washed live suspension of an enteropathogenic strain of Escherichia coli belonging to the O149:K91(B), K88ac(L) group. Different litters varied in their susceptibility to the strain; the mortality attributable to E.N.D. was 38 per cent. (20 of 53 piglets) but two of six litters were almost completely resistant to the enteropathogenic strain. This resistance did not appear to be related to a high level of bacterial agglutinins, somatic (O) antibodies or bactericidal activity in the colostrum. A formalin-killed vaccine derived from two isolates of the O149:K91(B), K88ac(L) group was administered in two doses without an adjuvant to six gilts during the last 4wk of pregnancy. The mortality attributable to E.N.D. in piglets from vaccinated dams was 20 per cent (11 of 54 piglets) following administration of the challenge dose. Although there was a reduction in the mortality of piglets from vaccinated compared with non-vaccinated dams, the reduction was not significant when the variation between Utters was taken into account. However, the bacteriological observations suggest that an antibacterial factor impaired the ability of the enteropathogenic strain to become established in the intestinal tract of piglets from vaccinated dams. This factor did not appear to be related to a high level of bacterial agglutinins, somatic (O) antibodies or bactericidal activity in colostrum and has yet to be identified in vitro.