Activation of Dendritic Cells in Tonsils is Associated with CD8 T Cell Responses Following Vaccination with Live Attenuated Classical Swine Fever Virus

Classical swine fever (CSF) is a highly contagious disease caused by the classical swine fever virus (CSFV). The live attenuated C-strain vaccine is highly efficacious, initiating protection within several days of delivery. The vaccine strain is detected in the tonsil early after inoculation, yet little is known of the role that tonsillar immune cells might play in initiating protection. Comparing the C-strain vaccine with the pathogenic CSFV Alfort-187 strain, changes in the myeloid cell compartment of the tonsil were observed. CSFV infection led to the emergence of an additional CD163+CD14+ cell population, which showed the highest levels of Alfort-187 and C-strain infection. There was also an increase in both the frequency and activation status (as shown by increased MHC-II expression) of the tonsillar conventional dendritic cells 1 (cDC1) in pigs inoculated with the C-strain. Notably, the activation of cDC1 cells coincided in time with the induction of a local CSFV-specific IFN-γ+ CD8 T cell response in C-strain vaccinated pigs, but not in pigs that received Alfort-187. Moreover, the frequency of CSFV-specific IFN-γ+ CD8 T cells was inversely correlated to the viral load in the tonsils of individual animals. Accordingly, we hypothesise that the activation of cDC1 is key in initiating local CSFV-specific CD8 T cell responses which curtail early virus replication and dissemination.

Efficiency Comparison of a Novel E2 Subunit Vaccine and a Classic C-Strain Vaccine against Classical Swine Fever

Classical swine fever (CSF) is one of the most important viral diseases in swine, causing severe economic losses in the swine industry. In China, CSF is one of the key diseases that needs to be controlled; the government has implemented control measures, and vaccination with C-strain vaccines (C-vacs) has been compulsory since the 1950s. C-vacs do not allow the differentiation of field virus-infected and vaccinated animals (DIVA). In 2012, China proposed a goal of eradicating CSF. Additionally, a baculovirus-expressed E2 subunit vaccine (E2-vac) was licensed in 2018. However, the C-vac and E2-vac characteristics have not been compared. Here, we demonstrate that both the C-vac and E2-vac provide complete protection against CSF in pigs. The E2-vac allows DIVA, and the E2 antibody responses of stimulated pigs are developed earlier and are stronger than the C-vac antibody responses. Therefore, the E2-vac is a new candidate licensed vaccine to completely eradicate CSF on pig farms.

BCG Vaccine Induced Tuberculous Osteomyelitis of Left Distal Femur in a Young Child: Case Report and Literature Review

Tuberculosis (TB) is an essential problem for healthcare systems especially in developing countries. TB continues to pose a significant global health burden [1]. Bacillus Calmette-Guérin (BCG) is an important vaccine used to prevent Tuberculosis (TB), especially meningeal TB and disseminated TB disease in children [2]. BCG is prepared from live bovine tuberculosis bacillus, and is given to protect against TB. Although vaccination against TB by means of BCG is widespread all over the world and is generally considered to be safe, but serious adverse reactions can occur. These may be minor such as abscess formation or skin ulceration at the site of vaccination to major adverse reaction such as fatal disseminated infection especially in patients with immune deficiency [3]. These adverse reactions after BCG vaccination depend on the BCG dose, vaccine strain, vaccine administration method, injection technique, and recipient’s underlying immune status [4]. The aim of this case report is to point out that clinical suspicion of BCG-induced osteomyelitis is warranted in pediatric patients with chronic symptoms of pain, limping, swelling and a limited ROM in the extremity. We also aimed to remind that imaging and culture studies may guide the clinician although tissue biopsies and genetic tests can confirm the histopathology and to review related articles.

Intratracheal inoculation of human varicella zoster virus (VZV; MAV strain) vaccine successfully induced VZV IgG antibodies in rhesus monkeys

Background The objective of this study was to investigate whether the use of live attenuated varicella zoster virus (VZV) MAV vaccination can efficiently induce VZV antibody production in naive rhesus monkeys as an approach to prevent simian varicella virus (SVV) reactivation in animals immunosuppressed for transplantation studies. Results Clinically available human VZV vaccine was used to induce the production of anti-VZV antibodies in rhesus monkeys. A vial of the vaccine was subcutaneously injected at 0 week, and the second and third vaccination was performed at 5 and 6 weeks by intratracheal inoculation. The titer of anti-VZV IgG was assessed at 0, 2, 4, 6, and 7 weeks. At 2 weeks, 3/16 were seropositive for VZV IgG. At 6 weeks, 9/16 were shown to be seropositive. At 7 weeks, 16/16 were found to be seropositive. Conclusions The VZV vaccine via intratrachael inoculation was shown to induce VZV IgG humoral immunity in rhesus monkeys and may be important immunosuppressed macaques for transplantation studies. Although the humoral immunity produced is an important finding, further studies will be necessary to confirm possible protection and it could protect probably against SVV infection in rhesus monkey.

Early and Solid Protection Afforded by the Thiverval Vaccine Provides Novel Vaccination Alternatives Against Classical Swine Fever Virus

Classical swine fever virus (CSFV) remains a challenge for the porcine industry. Inefficient vaccination programs in some endemic areas may have contributed to the emergence of low and moderate virulence CSFV variants. This work aimed to expand and update the information about the safety and efficacy of the CSFV Thiverval-strain vaccine. Two groups of pigs were vaccinated, and a contact and control groups were also included. Animals were challenged with a highly virulent CSFV strain at 21- or 5-days post vaccination (dpv). The vaccine induced rapid and strong IFN-α response, mainly in the 5-day immunized group, and no vaccine virus transmission was detected. Vaccinated pigs showed humoral response against CSFV E2 and Erns glycoproteins, with neutralising activity, starting at 14 days post vaccination (dpv). Strong clinical protection was afforded in all the vaccinated pigs as early as 5 dpv. The vaccine controlled viral replication after challenge, showing efficient virological protection in the 21-day immunized pigs despite being housed with animals excreting high CSFV titres. These results demonstrate the high efficacy of the Thiverval strain against CSFV replication. Its early protection capacity makes it a useful alternative for emergency vaccination and a consistent tool for CSFV control worldwide.

Development of a Simple Method for the Specific Detection of Anthrax Antibody in Sera by Colored Slide Agglutination Test

This study was aimed to identify humoral immune response against anthrax vaccine in mice model by using colored slide agglutination test and detection of field infectivity of anthrax. The field isolates of B. anthracis (n=05) and F34 stern strain vaccine was isolated on agar plates in order to carry out the slide agglutination test. The field isolates of B. anthracis and vaccine bacteria grew on PLET agar medium produced roughly circular and creamy white colonies with ground glass appearance. The bacteria on sheep blood agar media produced rough, sticky, white-gray non hemolytic colonies. Colony polymerase chain reaction (PCR) protocol was adapted to detect fragments of pX01 (596bp) and pX02 (777bp) plasmid of virulent field isolates of B. anthracis. The fragment of pX01 plasmid was only detected in vaccine bacteria. Growth of a field isolate and a vaccine bacteria were colored with crystal violet and used in slide agglutination test to detect anthrax antibodies. The anti-anthrax antibody was prepared by immunizing female mice with 100ül anthrax vaccine through subcutaneous route. Tail bleed were collected on day 0, 30, 60, 120 and 180 of immunization. Cardiac bleed was collected on day 180 of immunization for extensive study. 25μl of diluted (1:10, 1:20, 1:50 and 1:100) antisera and 25μl colored antigen was mixed together onto a clean slide at room temperature and the results was red following 5min, 10mins, 15mins and 20mins of reaction. Unstained antigens and non-immunized sera from the mice were used as control. Results of slide agglutination test showed that the colored vaccine bacteria and field isolates clumped the mice anti-antisera (day 30, 60, and 120) at 1:20 dilution as seen in naked eye but the reaction was seen only at 1:10 dilution while colorless antigens were used. Under microscopic investigation of slide agglutination test, the reaction was read up to 1:100 dilutions with the sera collected at day 30, 60, 120 and 180 of immunization. The Anthrax Sterne strain vaccine induced anti-anthrax immunity in mice that was detected until day 180 of immunization. The clumping reaction was distinct while colored anthrax antigen was used in slide agglutination tests. The colored slide agglutination tests protocol developed in this study can be used to detect anti-anthrax immune response and anthrax bacteria in the field condition with minimum laboratory facilities. Res. Agric., Livest. Fish.7(3): 497-506, December 2020

HUMORAL IMMUNE RESPONSE IN CROSS-BRED HEIFERS IMMUNIZED WITH BRUCELLA ABORTUS STRAIN RB51 VACCINE IN MILITARY DAIRY FARM OF BANGLADESH

Background: Brucellosis is a chronic zoonotic disease with negligible mortality rate that might be the reason not to attract the concerned authority to prevent and eradicate it in low income endemic countries. Recently, it has been recognized as a re-emerging zoonotic disease not only in low income countries but also its eradicated developed world. Objective: The main objective was to determine the humoral immune response (HIR) in crossbred dairy heifers immunized with Brucella abortus strain RB51 vaccine by using indirect ELISA Materials and Methods: Each of the 20 randomly selected B. abortus sero-negative crossbred (Holstein-Friesian  Local) dairy heifers aged between 4 to 8 months old at the Military Dairy Farm received 2.0 ml imported commercial B. abortus SRB51 strain vaccine subcutaneously in the neck region at day 0 and then booster dose at 60 days after first vaccination with similar dose and route during the period from June to October 2020. Each of the collected serum samples of 20 heifers at day 0, 7, 14, 21, 28, 60, 90, 120 and 150 was tested to detect the antibody status by using commercial indirect ELISA kit. Results: The humoral immune response (HIR) in terms of antibody levels detected by OD values in the serum of immunized cross-bred dairy heifers by using B. abortus strain RB51 commercial vaccine resulted 0.097  0.0032 (mean  SE) OD value at 0 day (i.e. pre-immunization) and 0.108 ± 0.0032 at 7th day. After that, the OD value started to rise from day 14 (OD value 0.124 ± 0.0032) and reached to a peak level at 60 days (OD value 0.223  0.0032) with the initial vaccination. Booster vaccination inoculated at 60 days resulted peak antibody level in terms of OD value (0.313  0.0032) at the day 90 and then the antibody level started to decline from 120 days (OD value 0.242  0.0032) to 150 days (OD value 0.199 0.0032) in cross-bred dairy heifers. Conclusions: This study suggests that the commercial B. abortus RB51 strain vaccine has induced satisfactory HIR with initial inoculation and significantly higher HIR produced with a booster dose in crossbred heifers by using commercial I-ELISA. The presence of Brucella antibodies have importance on sero-diagnosis whereas the cell mediated immunity (CMI) plays major role in protection against brucellosis which needs further investigation in cross-bred heifers in Bangladesh. Keywords: Brucellosis, SRB51 vaccine, Humoral immune response, I-ELISA, Cross-bred heifers, Bangladesh

Comparison of the Pathogenicity of Classical Swine Fever Virus Subgenotype 2.1c and 2.1d Strains from China

Classical swine fever (CSF) caused by classical swine fever virus (CSFV) is a highly contagious and devastating disease. The traditional live attenuated C-strain vaccine is widely used to control disease outbreaks in China. Since 2000, subgenotype 2.1 has become dominant in China. Here, we isolated subgenotype 2.1c and 2.1d strains from CSF-suspected pigs. The genetic variations and pathogenesis of subgenotype 2.1c and 2.1d strains were investigated experimentally. We aimed to evaluate and compare the replication characteristics and clinical signs of subgenotype 2.1c and 2.1d strains with those of the typical highly virulent CSFV SM strain. In PK-15 cells, the three CSFV isolates exhibited similar replication levels but significantly lower replication levels compared with the CSFV SM strain. The experimental animal infection model showed that the pathogenicity of subgenotype 2.1c and 2.1d strains was less than that of the CSFV SM strain. According to the clinical scoring system, subgenotype 2.1c (GDGZ-2019) and 2.1d (HBXY-2019 and GXGG-2019) strains were moderately virulent. This study showed that the pathogenicity of CSFV field strains will aid in the understanding of CSFV biological characteristics and the related epidemiology.

Evaluation of Glycosylated FlpA and SodB as Subunit Vaccines Against Campylobacter jejuni Colonisation in Chickens

Campylobacter jejuni is the leading bacterial cause of human gastroenteritis worldwide and the handling or consumption of contaminated poultry meat is the key source of infection. C. jejuni proteins FlpA and SodB and glycoconjugates containing the C. jejuni N-glycan have been separately reported to be partially protective vaccines in chickens. In this study, two novel glycoproteins generated by protein glycan coupling technology—G-FlpA and G-SodB (with two and three N-glycosylation sites, respectively)—were evaluated for efficacy against intestinal colonisation of chickens by C. jejuni strain M1 relative to their unglycosylated variants. Two independent trials of the same design were performed with either a high challenge dose of 107 colony-forming units (CFU) or a minimum challenge dose of 102 CFU of C. jejuni M1. While antigen-specific serum IgY was detected in both trials, no reduction in caecal colonisation by C. jejuni M1 was observed and glycosylation of vaccine antigens had no effect on the outcome. Our data highlight inconsistencies in the outcome of C. jejuni vaccination trials that may reflect antigen-, challenge strain-, vaccine administration-, adjuvant- and chicken line-specific differences from previously published studies. Refinement of glycoconjugate vaccines by increasing glycosylation levels or using highly immunogenic protein carriers could improve their efficacy.