Vaccination Of Calves Research Articles

PSXI-1 Evaluation of weaning methods on performance and immune response to vaccination in beef calves

Abstract The weaning process is a stressful experience for any species. Various weaning methods have been used in beef cattle to mitigate this stress and its associated consequences, such as decreased growth rate and suppression of the immune system. The objective of this study was to evaluate different weaning methods and their effect on post-weaning growth and immune function in beef calves. To accomplish this, a sample of Angus and Angus cross beef calves (n = 147) were stratified by age, sex, and sire and divided into three treatment groups: abrupt weaning (AW), fence line weaning (FL), and nose flap weaning (NF). All calves were vaccinated at weaning (d 0) and weaned according to their treatment group. Blood samples (5 mL) were collected via coccygeal venipuncture on d 0 and 14 to evaluate immune response to vaccination and quantify cortisol concentration as an indicator of stress. Individual body weights (BW) were recorded biweekly for 42 d after weaning. Data were analyzed using the PROC MIXED procedure of SAS v9.4 with main effects of treatment and sex and their interaction using ANOVA. Weaning weight, post-weaning weights, and post-weaning BW gain data were analyzed with age of calf included as a covariate. Body weights were not different among treatment groups at weaning, or at 14, 28, or 42 d post-weaning; however, the FL group had a greater (P < 0.05) total post-weaning BW gain than the AW group with the NF group being intermediate to the others. There was no effect of weaning method on cortisol concentration at weaning or 14 d post-weaning, but a difference in immune response was observed. Calves in the NF weaning group had a greater (P < 0.05) immune response to vaccination as determined by antibody titers than calves in the AW or FL weaning groups. Based on the results of this study, alternative methods of weaning may have a positive impact on calf BW gain throughout the post-weaning period and immune response to vaccination in recently weaned beef calves.

The safety of overdose and repeat administrations of BCG Danish strain 1331 vaccine in calves and pregnant heifers

Bovine tuberculosis (bTB), caused by Mycobacterium bovis infection, is a zoonotic disease in cattle that represents a significant ongoing challenge to cattle farming productivity and the livelihoods of livestock farmers in the UK. Vaccination of cattle with BCG could directly target the ability of M. bovis to proliferate within vaccinates, restricting bTB pathogenesis and onward disease transmission, and represent a step change in the tools available to help control bTB in farmed cattle. A Marketing Authorisation (MA) is required before a cattle BCG vaccine could be sold and supplied as a veterinary medicine within the UK and this requires comprehensive data supporting vaccine quality, efficacy and, most importantly, its safety. We carried out two independent Good Laboratory Practice (GLP) studies in which the safety of BCG vaccination in cattle was stringently tested through overdose and repeat vaccine administrations in young calves and pregnant heifers. Mild and generally short-lived reactions to vaccinations were observed in some animals, most commonly increases in body temperature and swelling at vaccine injection sites, but these did not have a negative impact on the overall health status of vaccinates. BCG was not shed in the saliva, faeces, milk or urine from vaccinated animals and its dissemination was limited to injection site tissues and associated lymph nodes. Overall, young calves and pregnant heifers vaccinated with BCG remained in good general health, and the vaccinated pregnant heifers had normal pregnancies and gave birth to healthy calves. Obtaining a Marketing Authorisation for a cattle BCG vaccine is a critical milestone in the progress towards the eventual use of BCG vaccination in cattle as an additional bTB control tool within the UK; these pivotal GLP vaccine safety studies generated the detailed and essential target animal safety data needed to support this.

Antibody levels following vaccination of beef calves with a tetanus toxoid

Tetanus is a preventable, yet often fatal, disease affecting many species, including beef cattle. Vaccination for tetanus is recommended for calves at high risk of disease, but typical beef cattle management practices often make adherence to vaccine manufacturers’ guidance for a second (booster) dose of vaccine difficult. This study examined the antibody response following a single dose of tetanus toxoid, as well as following booster vaccination at various intervals. Anti-tetanus IgG antibodies were detectable 25 days (D25) after a single dose, and rose following booster at either D25 D109 after initial vaccination. Antibody levels then declined numerically from D109 to D179 for calves boostered at D25 but rose on D179 for those receiving a second dose on D109. The relatively rapid response in IgG production, even in the absence of a booster vaccine, may suggest value in vaccinating calves for tetanus at time of greatest risk, even if a booster cannot be administered. The study also provides support for priming of the immune response lasting at least until D109 after primary immunization.

Evaluation of longitudinal passive immunity transfer against lumpy skin disease virus in calves by different serological methods

To implement effective lumpy skin disease (LSD) control measures, such as timely vaccination, particularly in calves and serological monitoring, it is necessary to evaluate immune response after vaccination, both in adult cattle and in their calves. The aim of this study was to evaluate passive immunity transfer and duration of maternal antibodies against lumpy skin disease virus (LSDV) in calves born to vaccinated cows by two different serological methods. The longitudinal study was carried out on two farms in Serbia where no cases were reported during LSD outbreak in 2016. Fifteen cows on each farm were vaccinated and revaccinated with attenuated vaccine - Neethling strain. A total of 30 cows and 30 calves on both farms were included in the study. Serum samples from cows were collected on calving day and serum samples from their respective calves on days 10, 20, 30, 45, 60, 75, 90, 105 and 120 after birth. Colostrum samples were collected only from 15 cows on one farm. In order to determine the presence of antibodies against LSDV a total of 30 cow sera samples, 15 colostrum samples and 270 calf sera samples were examined by commercial enzyme-linked immunosorbent assay (ELISA) and modified virus neutralization test (VNT). Overall, the performance of both serological tests was very satisfactory. The results of this longitudinal study showed that persistence of passive immunity in calves is less than 4 months, and that most calves are not protected against LSDV at that age. Since the vaccination is the most important control measure against LSDV, the recommended age of six months for vaccination of calves born to vaccinated cows should be reassessed to achieve the most optimal protection against LSD.

Vaccines for all stages

There are many vaccines to select from when developing proto­cols for beef cattle operations, and no single vaccine protocol is appropriate for all operations. Thus, vaccine protocol develop­ment requires understanding of the management of each op­eration. Unfortunately, current field trials confirming efficacy of vaccines to prevent disease in “real life” settings are not com­mon, and not all protocols have been tested. Thus, development of protocols for farm or ranch use often relies on experimental challenge studies or expert opinion. When vaccination of calves in the first 3 to 4 months of life is possible, vaccines for clostrid­ial infections and respiratory viral infections are most likely to be used to limit preweaning disease. On some operations, pre­weaning vaccination may be delayed until close to weaning if the aim is to limit postweaning disease. Vaccines likely appro­priate to limit postweaning disease include those for clostridial agents, agents that cause bovine respiratory disease, and agents likely to impact fertility in replacement heifers. Other vaccines may be appropriate on a case-by-case basis. Health records in­cluding vaccine timing and occurrence of disease in vaccinated animals can be a major help to confirm efficacy of vaccine pro­tocols. Veterinarians should periodically check for new sys­tematic reviews, meta-analyses, or randomized controlled field trials testing vaccines they used, to have the best information to use when planning vaccination protocols.

Effects of injectable trace minerals on the inflammatory cytokines’ response to vaccination in dairy calves

Trace mineral supplementation concurrent with the bovine respiratory diseases complex (BRDC) vaccine boosts antibody production and leukocyte proliferation. However, the mecha­nism underlying this effect is not well understood. On the other hand, cytokines response post-vaccination is an important driver of both humoral and cellular immunity. Therefore, we hypothesized that trace mineral supplementation may improve BRD vaccine immunogenicity and effectiveness by modulating inflammatory cytokines in dairy calves. Our objective was to characterize the effects of injectable trace minerals (ITM) on the cytokines response to the BRD modified-live virus (MLV) vaccine in post-weaning dairy calves.

Use of Immunostimulators in the Prevention of Coronavirus Disease in Calves

Vaccination and passive immunization, disinfection and biosecurity, feeding and feeding, care, hygiene and immune status of animals are essential to prevent BCoV diseases, limit the use of antibacterial drugs and reduce the subsequent emergence of microbial resistance, improve the quality of animal products and animals. Multivalent vaccines are now available to limit the spread of the virus and achieve hyperimmune herd passive immunization in calves, which may protect or reduce the severity of BCoV diarrhea in calves. The importance of passive immunization is noted. An oral live vaccine has also been developed to prevent diarrhea in calves. Studies have also been conducted on the use of intranasal BCoV vaccination in calves against bovine respiratory disease and winter dysentery.

Evaluation of a Combined Live Attenuated Vaccine against Lumpy Skin Disease, Contagious Bovine Pleuropneumonia and Rift Valley Fever.

The use of effective vaccines is among the most important strategies for the prevention and progressive control of transboundary infectious animal diseases. However, the use of vaccine is often impeded by the cost, a lack of cold chains and other factors. In resource-limited countries in Africa, one approach to improve coverage and reduce cost is to vaccinate against multiple diseases using combined vaccines. Therefore, the objective of this study was to evaluate a combined vaccine for the prevention and control of Lumpy Skin Disease (LSD), Contagious Bovine Pleuropneumonia (CBPP) and Rift Valley fever (RVF). The LSD and CBPP were formulated as a combined vaccine, and the RVF was formulated separately as live attenuated vaccines. These consisted of a Mycoplasma MmmSC T1/44 strain that was propagated in Hayflick-modified medium, RVF virus vaccine, C13T strain prepared in African green monkey cells (Vero), and the LSDV Neethling vaccine strain prepared in primary testis cells. The vaccines were tested for safety via the subcutaneous route in both young calves and pregnant heifers with no side effect, abortion or teratogenicity. The vaccination of calves induced seroconversions for all three vaccines starting from day 7 post-vaccination (PV), with rates of 50% for LSD, 70% for CBPP and 100% for RVF, or rates similar to those obtained with monovalent vaccines. The challenge of cattle vaccinated with the LSD/CBPP and the RVF vaccine afforded full protection against virulent strains of LSDV and RVFV. A satisfactory level of protection against a CBPP challenge was observed, with 50% of protection at 6 months and 81% at 13 months PV. A mass vaccination trial was performed in four regions of Burkina Faso that confirmed safety and specific antibody responses induced by the vaccines. The multivalent LSD/CBPP+RVF vaccine provides a novel and beneficial approach to the control of the three diseases through one intervention and, therefore, reduces the cost and improves vaccination coverage.

Brucellosis: obstacles to the vaccination of bovine and buffalo females in the Baixada Maranhense region

Objective: to identify obstacles to the vaccination of bovine and buffalo calves against brucellosis in of Matinha city, Maranhão, Brazil. Methods: interviews were carried out using a script composed of four blocks of questions: i) socioeconomic characteristics; ii) knowledge about proof of vaccination; iii) cattle owners' knowledge of the norms for vaccinating calves against brucellosis; and iv) preferences for participation in health guidelines. Results: it was found that most respondents are over 50 years old (62%), with incomplete primary school (32%) and family income of up to 01 minimum wage (66%). Less than half (48%) knew about the mandatory application of the vaccine against brucellosis. Conclusion: the biggest obstacle for the vaccination of calves against brucellosis in Matinha is the lack of knowledge of the breeders in relation to the disease, to understand the importance of vaccination in the control and prevention of the disease.

Effect of exogenous melatonin on the cellular response of Holstein heifer calves during vaccination.

Despite rigorous vaccination protocols, calf morbidity is the primary contributor to economic loss in the calf sector of the dairy industry. Melatonin has modulated immune response in other mature animal species. We hypothesized that exogenous melatonin may improve the cellular response to vaccination in dairy calves. Our objective was to evaluate the effect of exogenous melatonin on polymorphonuclear leukocyte (PMN) function in Holstein heifer calves during immunization. Sixty neonatal Holstein heifers were enrolled by birth cohort (block) and randomized to one of four treatments: control (CON), vaccination of 0.5mg ovalbumin on days 0 and 21 (VAC), implantation of 24mg melatonin on day 0 (MEL), or both melatonin and vaccine treatments (MVAC). Jugular blood was collected on days 0, 21, 42, and 63 to measure circulating melatonin, anti-ovalbumin immunoglobulin-G, and PMN function. Calves implanted with melatonin had greater circulating melatonin than non-implanted on day 21 (P < 0.01). Anti-ovalbumin IgG was greater for vaccinated than non-vaccinated calves (P < 0.01). Anti-ovalbumin IgG was greater for MVAC than VAC calves on day 63. Percent of cells and mean florescence intensity of cells performing oxidative burst decreased from day 0 to day 63 (P < 0.01) but were not affected by treatment (P ≥ 0.26). There was a tendency (P = 0.10) for an interaction of melatonin, vaccination, and day for the mean florescence intensity of cells performing phagocytosis where MVAC was greater than all other treatments on d 42. Exogenous melatonin may alter PMN function of calves during vaccination. Further research is needed to define the effect of melatonin on development of antigen-specific IgG during programmed vaccination protocols.

Maternally Derived Antibodies to Foot-and-Mouth Disease Virus Modulate the Antigenic Specificity of Humoral Responses in Vaccinated Cattle.

Vaccination is widely used to control foot-and-mouth disease (FMD), but maternal antibodies may interfere with the response to vaccination in calves. This study, conducted on a regularly vaccinated Malaysian dairy farm, aimed to optimise the vaccination regime by measuring the in vitro neutralising virus antibody responses of 51 calves before and after vaccination with a one or two dose vaccination regime starting at 2-7 months old. The presence of maternal antibodies was associated with poor post-vaccination antibody responses after a single dose of vaccine in calves less than 6 months old. However, a second dose of vaccine given three weeks later, improved the antibody responses in all ages of calves. This confirms the view that in regularly vaccinated farms, some combination of delay and revaccination is needed to achieve effective immunization of calves. Sera from cows and pre-vaccinated calves neutralised homologous serotype A vaccine virus more strongly than a heterologous serotype A field virus, but this pattern was reversed in some calves after vaccination. The strength of heterologous responses in calves 49 days after first vaccination correlated to the amount of transferred maternal antibody, suggesting that pre-existing antibodies could have modulated the specificity of these active antibody responses. If confirmed, such an effect by pre-existing antibodies could have wider implications for broadening the coverage of FMD vaccine responses.

Vaccination of calves with Bacillus Calmette-Guerin Danish strain 1331 results in a duration of immunity of at least 52 weeks

Bacillus Calmette-Guérin (BCG) Danish strain 1331 (CattleBCG) is currently the lead vaccine candidate for the control of bovine tuberculosis (TB) in cattle in GB, where prior vaccination has shown to result in a significant reduction in bovine TB pathology induced by infection with Mycobacterium bovis (M. bovis). A critical knowledge gap in our understanding of CattleBCG is the duration of immunity post vaccination at the minimum intended vaccine dose. To this end, we performed an experiment where calves were vaccinated with a targeted dose of 106 CFU and, after a period of 52 weeks, experimentally infected with M. bovis. Post mortem examination performed 13 weeks after infection revealed a statistically significant reduction in the severity of TB pathology in the CattleBCG vaccinated group compared with the unvaccinated control group. Additionally, this study allowed us to further assess the diagnostic performance of a defined antigen DIVA reagent (DST-F) developed to detect infected amongst vaccinated animals. Our results demonstrate that when used in a skin test format, DST-F showed high specificity (100 %) in BCG-vaccinated animals when tested prior to infection, whilst detecting all infected animals when re-tested after infection. Furthermore, we also present results supporting the use of the DST-F reagent in an interferon-gamma release assay. In conclusion, the results of this study demonstrate a 52-week duration of immunity following administration of a minimum dose of CattleBCG. This evidence will be a fundamental component in our efforts to apply for UK marketing authorisation to enable vaccination of cattle as a significant additional control measure in the ongoing fight against bovine TB in GB.

Specific and non-specific effects of Mycobacterium bovis BCG vaccination in dairy calves.

Bovine tuberculosis (bTB) is a chronic disease mainly caused by Mycobacterium bovis, a zoonotic pathogen with economic significance as it leads to reduced milk and meat production, and high costs for control measures. The Bacillus Calmette-Guérin (BCG) vaccine, primarily used to prevent tuberculosis in humans, has also been studied for controlling bTB. While showing effectiveness in preventing M. bovis infection and disease in cattle, the BCG vaccine can induce non-specific effects on the immune system, enhancing responses to infections caused by unrelated pathogens, and also having non-specific effects on lactation. The aim of this study is to describe both the specific and non-specific effects of BCG vaccination in calves from a commercial dairy herd in central Chile. Diagnosis of M. bovis infection was performed through the IFNγ release assay (IGRA) using ESAT6/CFP-10 and Rv3615c antigens. The records of milk production, somatic cell count (SCC), clinical mastitis (CM) and retained placenta (RP) during the first lactation were compared between vaccinated and non-vaccinated animals. The breed (Holstein Friesian [HF] v/s HF × Swedish Red crossbred [HFSR]) and the season (warm v/s cold) were also analyzed as categorical explanatory variables. Results of IGRA showed significant differences between vaccinated and control groups, indicating a vaccine efficacy of 58.5% at 18 months post vaccination in HFSR crossbred animals. Although milk production did not vary, SCC and CM showed differences between groups, associated to the breed and the season, respectively. When analyzing CM and RP as a whole entity of disease, BCG showed protection in all but the cold season variables. Overall, the BCG vaccine induced protective specific and non-specific effects on health parameters, which may be influenced by the breed of animals and the season. These results provide new features of BCG protection, supporting initiatives for its implementation as a complementary tool in bTB control.

Effects of an Appeasing Substance Application at Weaning on Growth, Stress, Behavior, and Response to Vaccination of Bos indicus Calves.

An analog of a bovine-appeasing substance (BAS) was previously demonstrated to have calming effects, and it could be an alternative to alleviate the stress caused by weaning. Thus, the objective of this study was to evaluate the effects of BAS administration at weaning on growth, stress, behavior, and response to vaccination of Nellore calves. Eighty-six Nellore calves (40 females and 46 males) were abruptly weaned and randomly assigned into 1 of 2 treatments: (1) saline solution (0.9% NaCl; n = 43) and (2) BAS (Secure Catte, IRSEA Group, Quartier Salignan, France; n = 43). The solutions were topically applied (5 mL/calf) to the nuchal skin area of each animal. On d 0, before treatment application, calves were vaccinated against infectious bovine rhinotracheitis (IBR), parainfluenza-3 (PI3) virus, and bovine viral diarrhea virus types 1 and 2 (BVDV-1 and 2). Calves from each treatment were kept in different pastures for 15 d (time of BAS action) and then moved to a single pasture. Body weight (BW), blood samples, and temperament in the chute (entry score, chute score, and exit score) were collected on d 0, 3, 8, 15, 51, and 100, and behavior on pasture on d 1, 2, 4, 5, 6, 7, and 9. Calves assigned to BAS vs. Saline treatment tended to have greater BW on d 15 (p = 0.10), tended to have lower entry scores on d 8 and 51 (p = 0.10), and chute scores on d 8 (p = 0.07), and had lower exit scores on d 8 (p = 0.02). Calves assigned to BAS vs. Saline treatment also had greater time grazing on d 7 and 9 (p < 0.01), eating concentrate on d 2, 5, and 6 (p = 0.05), walking on d 1, 2, 5, and 9 (p < 0.01), standing and ruminating on d 2, 7 and 9 (p < 0.01), and playing on d 2, 4, 6, 7, and 9 (p < 0.01). Furthermore, they had lower time lying on 1 and 2 (p < 0.01), standing on d 5 and 9 (p < 0.01), and vocalizing on d 1 and 2 (p < 0.01). Calves assigned to BAS vs. Saline treatment had greater serum titter concentrations of PI3 t on d 15 and 51 (p = 0.05) and BVDV-1 on d 51 (p = 0.02). However, they had lower serum concentrations of cortisol on d 3 (p = 0.03). BAS administration did not affect (p ≥ 0.12) the serum titer concentration of IBR and BVDV-2 titers or the plasma concentration of haptoglobin and ceruloplasmin. The BAS administration improved BW, reduced temperament and serum cortisol concentration, and improved behavior and response to vaccination.

Vaccination of cattle with the Babesia bovis sexual-stage protein HAP2 abrogates parasite transmission by Rhipicephalus microplus ticks

The apicomplexan parasite Babesia bovis is responsible for bovine babesiosis, a poorly controlled tick-borne disease of global impact. The widely conserved gametocyte protein HAPLESS2/GCS1 (HAP2) is uniquely expressed on the surface of B. bovis sexual stage parasites and is a candidate for transmission-blocking vaccines (TBV). Here, we tested whether vaccination of calves with recombinant HAP2 (rHAP2) interferes with the transmission of B. bovis by competent ticks. Calves vaccinated with rHAP2 (n = 3), but not control animals (n = 3) developed antibodies specific to the vaccine antigen. Vaccinated and control animals were infested with Rhipicephalus microplus larvae and subsequently infected with virulent blood stage B. bovis parasites by needle inoculation, with all animals developing clinical signs of acute babesiosis. Engorged female ticks fed on the infected calves were collected for oviposition, hatching, and obtention of larvae. Transmission feeding was then conducted using pools of larvae derived from ticks fed on rHAP2-vaccinated or control calves. Recipient calves (n = 3) exposed to larvae derived from control animals, but none of the recipient calves (n = 3) challenged with larvae from ticks fed on rHAP2-vaccinated animals, developed signs of acute babesiosis within 11 days after tick infestation. Antibodies against B. bovis antigens and parasite DNA were found in all control recipient animals, but not in any of the calves exposed to larvae derived from HAP2-vaccinated animals, consistent with the absence of B. bovis infection via tick transmission. Overall, our results are consistent with the abrogation of parasite tick transmission in rHAP2-vaccinated calves, confirming this antigen as a prime TBV candidate against B. bovis.

THE ROLE OF COLOSTURAL INDICATORS IN PREVENTION CORONAVIRUS AND ROTAVIRAL DIARRHEA IN CALVES

One of the main conditions for increasing the productivity of animal husbandry is the protection of newborn calves from early death. The leading place among these diseases belongs to infectious diseases with the diarrhea syndrome in newborns. Gastrointestinal diseases of calves, as usually, are polyetiological in nature and caused by various infectious agents: viruses, bacteria, chlamydia, mycoplasmas, fungi, protozoa and others. In the presented study, indicators of the quality of colostrum and vaccination of newborn calves were measured, and such indicators in animals as proteins, fats, lactose, IgG immunoglobulin levels were analyzed. Experiments were carried out on 50 animals. The results obtained confirmed that high-quality colostrum increases the resistance of calves to diseases.

Protective Efficacy of BCG Vaccination in Calves Vaccinated at Different Ages.

Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB), is a globally prevalent pathogen with significant animal welfare, economic and public health impacts. In the UK, the control of bTB relies on detection via tuberculin skin tests with ancillary interferon gamma (IFN-γ) release assays, followed by culling infected animals. Vaccination with Bacille Calmette-Guérin (BCG) could be an important element of bTB control, and a number of studies have demonstrated its protective efficacy, particularly when young calves are vaccinated. Here, we compared immune responses and the protective efficacy of BCG in calves vaccinated within the first day of life and at three weeks of age. Significant protection from M. bovis infection was observed in BCG-vaccinated calves compared to non-vaccinated, age-matched controls. No significant differences were shown between calves vaccinated at one day and at three weeks of age when assessing the protective efficacy of BCG (measured as a reduction in lesions and bacterial burden). Antigen-specific IFN-γ levels were similar between the BCG-vaccinated groups, but significantly different from the non-vaccinated control animals. Antigen-specific IFN-γ expression post-BCG vaccination was correlated significantly with protection from M. bovis infection, whereas IFN-γ levels post-challenge correlated with pathology and bacterial burden. These results indicate that early-life vaccination with BCG could have a significant impact on M. bovis infection and, therefore, bTB incidence, and they demonstrate that age, at least within the first month of life, does not significantly impact the protective effect of vaccination.

Cytogenetic disorders in young cattle vaccinated against trichophytosis

This article continues a series of works by the authors devoted to most of the karyopathological effects of vaccines used in agriculture. The authors of the test cytogenetic analysis of the impact caused by the LTF130 vaccine from an attenuated culture of the fungus Trichophyton verrucosum TF-130 L VGNKI in peripheral blood lymphocytes of healthy 30-day-old healthy Holstein Colonial calves. The experiment was conducted on the material and technical basis of two departments: veterinary genetics and biotechnology, epizootiology and microbiology, FSBEI HE “Novosibirsk State Agrarian University”. The authors found that the spectrum of induced cytogenetic disorders included polyploid, hyper- and hypoploid cells, chromatid and chromosome breaks, and single and paired fragments of chromosomes, regardless of the time since the introduction of the vaccine. They did not differ from the spectrum of spontaneously occurring mutations in this species. It was noted that among cells with a changed number of chromosomes, polyploid cells with tetraploid sets (79.3–91.9%) and aneuploid cells with hypoploid sets (45.7–74.3%) of chromosomes predominated. The authors found a decrease in the frequency of polyploid cells seven days after vaccination of calves against trichophytosis to 1.6%, control - 3.4 ± 0.57% (P &lt; 0.01). An increase in the frequency of hyperploid cells 14 days after vaccination of calves against trichophytosis up to 3.69% was revealed due to trisomy (2.91 ± 0.74%, P &lt; 0.05) and tetrasomy (0.78 ± 0.39%, P &lt; 0.01). An increase in the frequency of cells with chromosome aberrations was found 2 and 7 days after vaccination of calves against trichophytosis, respectively, to 5.74 and 5.24% due to breaks (4.49 ± 1.03 and 3.31 ± 0.66%, P &lt; 0.01–0.01) and paired fragments of chromosomes (1.38 ± 0.43%, Р &lt; 0.05).

Characterization of humoral and cellular immune responses elicited by reduced doses of Brucella abortus S19 (calfhood) vaccine in cattle calves of India

Brucella abortus S19 vaccine is a stable attenuated smooth strain, globally used as calfhood vaccine for the prevention of bovine brucellosis. Various agencies demonstrated different doses for vaccinating cattle and buffalo calves leading to ambiguity in selecting a suitable immune vaccine dose. The current study aimed at evaluating four graded doses of S19 vaccine to arrive at the dose which could produce comparable effectiveness as that of full dose prescribed by Indian Pharmacopeia among the Indian calves. Four vaccine doses of which the first dose consisted of full dose (40 × 109 CFU/dose) and the other three were 1/10th, 1/20th, 1/100th reduced doses along with control were tested. Each vaccine dose was administered to 13 cattle calves of 4–5 months of age maintained in separate groups. The blood samples were collected on 0 to 240 days post-vaccination (DPV) at the intervals of 0, 14, 28, 45, 60, 90, 150, 180 and 240 for assessment of vaccine-induced innate, humoral and cell-mediated immune responses. The sero-conversion of all vaccinated animals on DPV 45 and persistence of antibody till DPV 240 were noticed. No significant differences were observed in antibody response between animal groups that received full and 1/10th reduced doses. Innate and cell-mediated response by IL-6, TNF-α¸ IFN-γ, CD4+ and CD8+ cell counts showed dose-dependent responses with no significant difference between full dose and 1/10th reduced doses. The results suggest a possible one log reduction of full dose without compromising immune responses to aid larger vaccination coverage for creating herd immunity.

Vaccination of calves at day of birth with attenuated vaccines against bovine respiratory syncytial virus, bovine parainfluenza type 3 virus and respiratory bovine coronavirus

Vaccination of calves at day of birth with attenuated vaccines against bovine respiratory syncytial virus, bovine parainfluenza type 3 virus and respiratory bovine coronavirus