Protective Antibody Titers Research Articles

Factors predicting the level of vaccine protection against hepatitis B virus infection among physicians and nurses in Šabac, Serbia.

As healthcare workers run a high and constant occupational risk of hepatitis B virus (HBV) infection through exposure to biological material, vaccination is mandatory as well as the monitoring of antibody levels one to two months after complete immunisation. The aim of this descriptive cross-sectional study was to determine HBV vaccine coverage of 200 primary and secondary healthcare workers (100 each) from Šabac, Serbia and their blood anti-HBs titre. We also wanted to identify factors that could predict the titre. Anti-HBV vaccination covered all participants, of whom 89.5 % were fully vaccinated, and 85 % had a protective antibody titre. We found a statistically significant association between antibody titre and the number of received vaccine doses, chronic jaundice, autoimmune disease, and cancer in our participants. The fact that 15 % did not achieve the protective antibody titre confirms the necessity of its control after immunisation, which is not routinely carried out in most countries, Serbia included. It is, therefore, necessary to develop a detailed strategy for monitoring vaccination and serological status of healthcare workers in order to improve their safety at work. An important role should also be given to continuous education of healthcare workers from the beginning of schooling to the end of their professional career.

Preclinical Evidence for the Protective Capacity of Antibodies Induced by Lyme Vaccine Candidate VLA15 in People.

Vaccine candidate VLA15 is designed to protect against the dominant Borrelia genospecies-causing Lyme disease in North America and Europe. Active immunization with VLA15 has protected in the mouse model of tick challenge. VLA15 is currently under evaluation in clinical studies for the prevention of Lyme borreliosis. Mice were passively administered sera from clinical trial participants vaccinated with VLA15, or normal human serum from unvaccinated individuals as control. Posttransfer serum anti-outer surface protein A (OspA) immunoglobulin G titers were assessed by enzyme-linked immunosorbent assay. Following passive transfer, mice were challenged with Ixodes ticks colonized with Borrelia burgdorferi (OspA serotype 1) or Borrelia afzelii (OspA serotype 2) and infection was determined by serology for VlsE C6 or by polymerase chain reaction and culture to assess the presence of Borrelia bacteria. Passive transfer of immune sera prevented transmission of Borrelia from the tick vector and protected mice against challenge. Posttransfer protective threshold immunoglobulin G antibody titers were observed in this animal model of 131 U/mL for B burgdorferi (OspA serotype 1) and 352 U/mL for B afzelii (serotype 2). Passive transfer of sera from trial participants immunized with VLA15 protected mice from borreliosis in a tick challenge model. This indicates that VLA15 induces functional immune responses in people that can be linked to efficacy in a stringent preclinical model.

Minimal Protective Antibody Titers Elicited in Sheep by RVFV MP-12 and arMP-12ΔNSm21/384 Vaccine Candidates

The live attenuated Rift Valley Fever Virus (RVFV) vaccine candidates, RVFV MP-12, and the recombinant derivative, RVFV arMP-12ΔNSm21/384 (MP-12NSm-del), are among the most promising next-generation domestic ruminant vaccine candidates. While both vaccines consistently elicit protective neutralizing Antibodies (nAb) in domestic ruminants, the minimal protective antibody titer is unknown. Therefore, we conducted studies to determine the minimal protective nAb titers elicited in sheep by these vaccines using a mouse model. The approach involved the transfer of sera obtained from sheep vaccinated with the MP-12 and MP-12NSm-del vaccines to 6- to 8-week-old BALB/c mice. The sheep nAb titers ranged from 20 to 640 at the time of transfer. A blood sample was obtained from each mouse 24 hours post-transfer to determine the nAb titer 2 hours before challenging each animal with a lethal dose of virulent RVFV (strain ZH501). All challenged mice were observed daily for 21 days for morbidity and mortality. The lowest nAb titer that protected the animals was interpreted as an estimate of the minimal protective efficacy of the vaccine. The results indicated that nAb titers as low as 10 to 20 elicited by the MP-12 and MP-12NSm-del vaccine candidates in sheep 10 days post-vaccination afforded protection to the mice. However, the nAbs elicited in one sheep by MP-12 before day 10 post-vaccination and ranging in titer from < 5 to 40 only afforded protection to 3 out of 18 mice, and therefore suggested that innate and/or the cellular immune response were also needed for protection during early RVFV infection. The findings further support these RVFV candidate vaccines as potential veterinary vaccines for domestic ruminants and offer a promising BALB/c mouse RVFV challenge model as a surrogate for evaluating the protective nAb response elicited by RVFV vaccines.

Seroprevalence of Protective Antibodies Against Influenza and the Reduction of the Influenza Incidence Rate: An Annual Repeated Cross-Sectional Study From 2014 to 2019.

Seroepidemiological studies provide estimates of population-level immunity, prevalence/incidence of infections, and evaluation of vaccination programs. We assessed the seroprevalence of protective antibodies against influenza and evaluated the correlation of seroprevalence with the cumulative annual influenza incidence rate. We conducted an annual repeated cross-sectional seroepidemiological survey, during June-August, from 2014 to 2019, in Portugal. A total of 4326 sera from all age groups, sex, and regions was tested by hemagglutination inhibition assay. Seroprevalence and geometric mean titers (GMT) of protective antibodies against influenza were assessed by age group, sex, and vaccine status (65+ years old). The association between summer annual seroprevalence and the difference of influenza incidence rates between one season and the previous one was measured by Pearson correlation coefficient (r). Significant differences in seroprevalence of protective antibodies against influenza were observed in the population. Higher seroprevalence and GMT for A(H1N1)pdm09 and A(H3N2) were observed in children (5-14); influenza B seroprevalence in adults 65+ was 1.6-4.4 times than in children (0-4). Vaccinated participants (65+) showed significant higher seroprevalence/GMT for influenza. A strong negative and significant correlation was found between seroprevalence and ILI incidence rate for A(H1N1)pdm09 in children between 5 and 14 (r = -0.84; 95% CI, -0.98 to -0.07); a weak negative correlation was observed for A(H3N2) and B/Yamagata (r ≤ -0.1). The study provides new insight into the anti-influenza antibodies seroprevalence measured in summer on the ILI incidence rate in the next season and the need for adjusted preventive health care measures to prevent influenza infection and transmission.

Effects of astragalus extract, levamisole and ascorbic acid on humoral immunity in chickens vaccinated with newcastle disease vaccines

This study was designed to assess the effects of Astragalus extract, levamisole and ascorbic acid on the humoral immune response of chickens vaccinated with live and inactivated Newcastle Disease (ND) vaccines. Sixty day-old Cobb500 broiler chicks were used for the study. At day old, the maternally derived antibodies (MDA) to ND virus was determined and the chicks were then housed in a bio-secured pen with water and feed given ad-lib. On the sixth day, the MDA decay was determined thereafter, the chicks were shared into 4 treatment groups. Group A (Astragalus extract); Group B (levamisole); Group C (ascorbic acid) and Group D (Control) of 15 chicks each. Response to ND vaccinations was determined through bleeding to obtain sera for haemagglutination inhibition test at 7 and 14 days except for the second booster with inactivated Komarov vaccine where it was done at 7, 14 and 21 days post vaccination respectively. Antibody titres in the chicks 7 days post first dose of vaccination with La Sota was high in all the treatment groups above the control with 100 % of the chicks having protective antibody titre of ≥4 log2 until day 30 when the antibody titres in all the groups dropped drastically following the second dose of live La Sota vaccination as the first booster vaccine. However, following the second booster with inactivated Komarov the antibody titres increased in all the treatment groups in comparison to the control especially in groups B and C with GMTs of 5.8 ± 0.19 log2 and 6.1 ± 0.27 log2 respectively. We observed that ascorbic acid and Levamisole may have humoral immuno-stimulating effects on vaccinated chickens through yet to be fully explored mechanism. It is recommended that ascorbic acid or levamisole could be used during vaccinations as immuno-stimulating agents to enhance humoral antibody response in vaccinated flocks.

Dosing of Convalescent Plasma and Hyperimmune Anti-SARS-CoV-2 Immunoglobulins: A Phase I/II Dose-Finding Study.

During the COVID-19 pandemic, trials on convalescent plasma (ConvP) were performed without preceding dose-finding studies. This study aimed to assess potential protective dosing regimens by constructing a population pharmacokinetic (popPK) model describing anti-SARS-CoV-2 antibody titers following the administration of ConvP or hyperimmune globulins (COVIg). Immunocompromised patients, testing negative for anti-SARS-CoV-2 spike antibodies despite vaccination, received a range of anti-SARS-CoV-2 antibodies in the form of COVIg or ConvP infusion. The popPK analysis was performed using NONMEM v7.4. Monte Carlo simulations were performed to assess potential COVIg and ConvP dosing regimens for prevention of COVID-19. Forty-four patients were enrolled, and data from 42 were used for constructing the popPK model. A two-compartment elimination model with mixed residual error best described the Nab-titers after administration. Inter-individual variation was associated to CL (44.3%), V1 (27.3%), and V2 (29.2%). Lean body weight and type of treatment (ConvP/COVIg) were associated with V1 and V2, respectively. Median elimination half-life was 20 days (interquartile range: 17-25days). Simulations demonstrated that even monthly infusions of 600mL of the ConvP or COVIg used in this trial would not achieve potentially protective serum antibody titers for >90% of the time. However, as a result of hybrid immunity and/or repeated vaccination, plasma donors with extremely high antibody titers are now readily available, and a >90% target attainment should be possible. The results of this study may inform future intervention studies on the prophylactic and therapeutic use of antiviral antibodies in the form of ConvP or COVIg. NL9379 (The Netherlands Trial Register).

Seroprevalence to Hepatitis B Virus among Prisoners Taking into Account Age, HIV Status, and Injection Drug Use

Relevance. Prisoners have a high risk of contracting hemocontact viral infections (including HIV, viral hepatitis B and C, etc.), which creates an additional infectious burden on the entire population living in the territory. Aims. To study the level of immune protection to viral hepatitis B in risk groups (age, HIV status, and injection drug use) of persons held in places of detention to identify those in need of vaccine prophylaxis. Materials & Methods. 343 blood serum samples obtained in 2021 from males with negative HBsAg status were studied. Anti-HBs antibodies to HBsAg were determined using a set of reagents “VectoHBsAg-antibodies” (Vector-Best, Russia). Results and discussion. The protective titer of anti-HBs antibodies was detected in 44.0% (n = 151) of cases, and was absent in 56.0% of the subjects. At the same time, anti-HBs was significantly more often detected in people living with HIV/AIDS (p = 0.038), injecting drug users (p = 0.002), as well as young people born after 1984 (p = 0.019). Conclusion. The lack of a significant level of collective immunity among prisoners, primarily the older age group before 1984, their risky behaviors (sexual, injection) indicate the need for active identification of seronegative persons serving sentences in places of detention and specific immunoprophylaxis.

Canine parvovirus type 2 (CPV-2) serological and molecular patterns in dogs with viral gastroenteritis from southern Brazil.

Canine Parvovirus type 2 (CPV-2) is a highly contagious virus that can cause severe systemic disease with gastroenteric symptoms in dogs, particularly in young puppies. Originating from the feline parvovirus in the late 1970s, it swiftly propagated globally, instigating a pandemic in dogs. Despite vaccination advancements, CPV-2 remains a substantial challenge for veterinary professionals and pet owners. This study aimed to contribute knowledge about the current situation of CPV-2 among dogs in southern Brazil. In this study, the sera of 125 dogs (mostly with gastroenteritis symptoms) were screened for antibodies against CPV-2 and their faeces for the virus itself. The results showed that 40% (50/125) of dogs were infected with CPV-2. Most animals (65.5%) had previously been exposed to CPV-2 (with serotitres equal or above 1:40), and only 37.6% had protective antibody titres equal or above 1:80. The findings have also demonstrated that vaccination against CPV-2 significantly reduced the risk of infection, with positive cases decreasing from 56.9% (unvaccinated) to 2.0% (fully vaccinated). Furthermore, the prevalence of CPV-2 decreased as dogs aged, with younger dogs and those with an incomplete or non-existent vaccination history at the highest risk of infection. In conclusion, this study provides valuable insight into the prevalence and risk factors associated with CPV-2 infection in dogs in southern Brazil, thereby providing valuable knowledge for the improvement of veterinary care and pet health.

Immune reconstitution, vaccine responses, and rituximab use after ex-vivo CD34-selected myeloablative allogenic hematopoietic cell transplantation.

Myeloablative T cell depleted (CD34-selected) hematopoietic cell transplantation (HCT) is associated with less acute and chronic graft versus host disease (GVHD). We aimed to examine vaccine responses in relation to immune reconstitution and post HCT rituximab administration in this population. This single center retrospective study included 251 patients with hematological malignancies who received a first CD34-selected HCT between 2012 and 2015. Of 251 patients, 190 were alive 1 year after HCT. Among the entire population, 77 (30.7%) patients were vaccinated. After vaccine administration, 35/44 (80%), 30/75 (40%), 27/36 (75%), 33/65 (51%), 34/51 (51%), 22/28 (79%) and 20/34 (59%) of evaluable patients had protective antibody titers for haemophilus influenzae type B (Hib), Pneumococcus, Tetanus, Diphtheria, Pertussis, hepatitis A (HAV), and hepatitis B (HBV) respectively. Responders to the pneumococcal vaccine had a higher CD45RA T cell count than non responders, with 12/18 patients (66.7%) vs 11/32 (34.4%) p = 0.04. For pneumococcal vaccine, there was also a trend to higher total lymphocyte B cell count in responders vs non responders p = 0.06. Rituximab post HCT was given to 59/251 (23.5%) patients. No difference was found in immune reconstitution patterns for rituximab use between vaccine responders and not. Recipients of CD34-selected HCT may respond to vaccination, and T and B cell subsets could be useful to predict vaccine response.

Effect of garlic flour (Allium sativum) addition on immunity and histopathology of Broilers with Newcastle disease virus

Broiler chickens are reared for a short period (35 days) of time for their flesh. When producing broilers, several issues develop, including low productivity, immunological state, feed prices, and antibiotic restrictions. Antibiotics ought to be avoided as growth promoters to avoid antimicrobial resistance (AMR). This policy stimulates broiler livestock productivity by utilizing plant elements known as photobiotic. The use of plant materials is intended to lower the risk of antibiotic resistance. Antibiotics that fail to meet regulations might cause residue buildup. Aside from it, there are several infectious disorders, such as Newcastle disease (ND). ND is a disease that frequently affects poultry, resulting in decreased production value, significant morbidity, and high mortality. ND can be prevented with vaccination and treatment to boost immunity. One type of vaccine utilizes immunomodulatory supplements, such as garlic (Allium sativum), which has anti-inflammatory and immune-boosting properties. During the ND infection, garlic flour supplementation resulted in alterations in pathological lesions in the hearts of chicken embryos. These modifications include a reduction in the severity of the infection, which is characterized by edema, congestion, necrosis, and neutrophil infiltration. After ND infection, 1% garlic flour can improve livestock immune health, as evidenced by an increase in protective antibody titers, a drop in the number of leukocytes, and a decrease in the number of lymphocytes. In the 1% garlic flour therapy group, histopathology of the spleen organ revealed differences in the severity of pathological lesions caused by ND infection.

Dietary Supplementation with Nucleotides, Short-Chain Fructooligosaccharides, Xylooligosaccharides, Beta-Carotene and Vitamin E Influences Immune Function in Kittens

Nucleotides, short-chain fructooligosaccharides (scFOS), xylooligosaccharides (XOS), β-carotene and vitamin E are reported to enhance immune function; however, the evidence of this in cats is limited. The aim of this study was to determine the immunomodulatory effects of these ingredients in kittens. Forty domestic short hair kittens were designated in litters to control or test diet for 28 weeks. Test diet was fortified with 0.33 g nucleotides, 0.45 g scFOS, 0.3 g XOS, 0.7 mg β-carotene and 66.5 mg vitamin E per 100 g diet. Kittens were vaccinated against feline parvovirus (FPV) and herpesvirus (FHV) at 10, 14 and 18 weeks. Kittens remained healthy, with no measured evidence of adverse health. Serum FPV and FHV antibody titres were significantly (p < 0.05) higher in the test diet group at week 23 and 27, respectively. A significantly (p < 0.05) higher proportion of test diet group kittens demonstrated an adequate response (four-fold titre increase) to FHV vaccination and a significantly (p < 0.05) higher proportion reached a protective antibody titre for FHV. Serum IgM was significantly (p < 0.05) higher in the test diet group. The test diet group demonstrated a stronger humoral immune response to vaccination, suggesting the diet supports immune defence, enabling a greater response to immune challenges.

ANTIBODY TITERS AGAINST NEWCASTLE DISEASE AND INFECTIOUS BRONCHITIS VIRUSES IN BROILER BREEDERS RAISED UNDERFLOOR VERSUS CAGE SYSTEM

The experiment was evaluated to find out the serum antibody titer of broiler breeders raised under different rearing systems (cage vs. floor) against Newcastle disease virus and infectious bronchitis disease virus. Two hundred and forty-day-old broiler breeders were equally divided into six groups Floor (V+CH), (V+Not CH) and (Not V+CH) and cage (V+CH), (V+Not CH), and (Not V+CH). Birds were vaccinated with Mukteswar, La Sota, and Massachusetts M41 in 1st week, 3rd week, and 4th week. Blood /serum samples were collected at 42 days of age. Collected data were analyzed by using a complete randomized design. The geometric mean titer (GMT) for Newcastle disease virus (NDV) of broiler breeders reared under floor versus cage housing system was measured by using the hem agglutination inhibition test and the defensive potentiality of vaccines was measured by determining the survivability rate of chickens by challenge infection. Birds vaccinated and virus-challenged showed a protective antibody titer against Newcastle disease virus in both housing systems. Significantly higher GMT was recorded for the non-vaccinated group having virus-challenged in cage female (9.76 ±0.34) and floor female (9.94 ±0.23). Protective antibody titer was calculated for broiler breeders who were regularly vaccinated. There were no significant differences (P≥0.05) observed in the cage versus floor housing system. Higher serum antibody titer in caged females (9.22±0.36) and floor (8.98±0.32) was calculated due to infection challenges. Morbidity and mortality were significantly affected by the cage and floor-rearing system. Frequencies of diseased birds and mortality were found higher on the floor compared to cages in the non-vaccinated group. Despite the regular vaccination sick female broiler breeders were found higher compared to cage broiler breeders. In the non-vaccinated group floor reared birds have a higher percentage of morbidity and mortality compared to cages. In conclusion cage and floor-rearing systems have no adverse effect on serum antibody titer and survivability of broiler breeders.

Propositive follow-up: Long-term immune responses to the 4CMenB and MenACWY vaccines in people living with HIV.

People living with HIV have an increased risk of meningococcal disease. The Propositive trial evaluated co-administration of two doses of a four-component recombinant protein-based MenB vaccine (4CMenB) and a quadrivalent conjugate polysaccharide MenACWY vaccine (MenACWY-CRM197) given 1 month apart in people with HIV. The follow-up trial assessed the immunogenicity of these vaccines at 1.5 and 2.5 years after primary vaccination. Participants who completed the parent Propositive trial were invited to the follow-up study. Immunogenicity analysis was performed at 18 and 30 months after primary vaccination. Primary outcome measures were serum bactericidal antibody (SBA) geometric mean titres (GMTs) against three MenB reference strains and the proportion of participants maintaining a protective SBA titre of ≥4 at 18 and 30 months. Secondary outcome measures were SBA GMTs against MenA, C, W, and Y serogroups and the proportion of participants maintaining a protective SBA titre of ≥8 at 18 and 30 months. The trial is registered with Clinicaltrials.gov (NCT042394300). A total of 40 participants aged 22-47 years were enrolled. Geometric mean titres waned by 18 and 30 months but remained higher than pre-vaccination for all MenB strains and MenA, C, W, and Y. In total, 75%-85% of participants retained protective SBA titres by 30 months against individual MenB strains, whereas 68.8% of patients retained protective antibody titres against all three MenB strains. Antibodies against MenC waned more rapidly than did those against MenA, W, and Y. The proportion of participants with protective titres against MenC at 30 months was also lower (46.9%) than that with protective titres against MenA (87.5%), W (78.1%), and Y (87.5%). Immune responses against MenB in our cohort of people living with HIV at 2.5 years of follow-up were reassuring, with 68.8% of participants retaining protection against all three reference strains. However, responses against MenC were lower than those against MenA, W, and Y serogroups.

Prevalence of Serum Antibody Titers against Core Vaccine Antigens in Italian Cats.

Feline core vaccines strongly recommended for all cats are against Feline panleukopenia virus (FPV), Felid herpesvirus type 1 (FeHV-1), and Feline calicivirus (FCV), but cats can be classified as low- and high-risk based on their lifestyle. The aim of this study was to determine the actual seroprotection against FPV, FeHV-1, and FCV in a large cohort of Italian cats by using the VacciCheck test. A total of 740 cats (567 owned and 173 stray cats; 435 vaccinated and 305 unvaccinated) were analyzed for Protective Antibody Titers (PATs). Differences related to origin, sex, age, breed, FIV/FeLV status, health status, and time elapsed since last vaccination were evaluated. Less than half of the entire cohort (36.4%) had PATs for all three diseases simultaneously, increasing to 48.6% if weak positive values were also considered and 50.3% when considering only the 435 vaccinated cats. Particularly, antibodies were detected against FCV, FPV, and FeHV-1 at protective titers (PATs) in 78.6%, 68.1, and 49.1% of the cats, respectively. In general, owned, neutered, and adult FIV- and/or FeLV-negative cats were the most protected categories, even if not always for the three viruses. Most cats maintained high PATs for 3 years or longer after vaccination against FPV and FCV but not FeHV-1. Long-lasting protective immunity persisted for many years after the last vaccination (more than 18 years in the oldest cats). Nevertheless, since not all cats were protected after so many years and for all pathogens, checking protection via antibody titration could be the best choice to prevent immunity breakdowns. The discussion also focuses on the reliability of antibody titration for the two URTD (upper respiratory tract disease) viruses which, unlike for FPV, is not widely accepted as a valid index of protection.

Evaluation of Humoral Response following SARS-CoV-2 mRNA-Based Vaccination in Liver Transplant Recipients Receiving Tailored Immunosuppressive Therapy.

Background: The role of tailored immunosuppression (IS) in the development of the humoral response (HR) to SARS-CoV-2 mRNA-based vaccination in liver transplant (LT) recipients is unknown. Methods: This is a single-centre prospective study of patients who underwent LT between January 2015 and December 2021 and who have received three doses of mRNA-based SARS-CoV-2 vaccination. Patients undergoing Tacrolimus-based immunosuppression (TAC-IS) were compared with those undergoing Everolimus-based immunosuppression (EVR-IS). Patients receiving the TAC-EVR combination were divided into two groups based on trough TAC concentrations, i.e., above or below 5 ng/mL. HR (analysed with ECLIA) was assessed at 30 to 135 days after vaccination. The primary outcome was the presence of a positive antibody titre (≥0.8 U/mL). Secondary outcomes were the presence of a highly protective antibody titre (≥142 U/mL), median antibody titre, and incidence of COVID-19. Results: Sixty-one participants were included. Twenty-four (40%) were receiving TAC-IS and thirty-seven (60%) were receiving EVR-IS. At the median follow-up of 116 (range: 89-154) days, there were no significant differences in positive antibody titre (95.8% vs. 94.6%; p = 0.8269), highly-protective antibody titre (83.3% vs. 81.1%; p = 0.8231), median antibody titre (2410 [IQ range 350-2500] vs. 1670 [IQ range 380-2500]; p = 0.9450), and COVID-19 incidence (0% vs. 5.4%; p = 0.5148). High serum creatinine and low estimated glomerular filtration rate were risk factors for a weak or absent HR. Conclusions: Three doses of mRNA-based SARS-CoV-2 vaccination yielded a highly protective HR in LT recipients. The use of TAC or EVR-based IS does not appear to influence HR or antibody titre, while renal disease is a risk factor for a weak or null HR.

Hepatitis B Immunity Status among Healthcare Sciences Students, 20 Years after the Infantile Vaccination: The Most Appropriate Policy to Confer Full Protection.

Abstract 
 Background. During recent years, an increasing number of previously vaccinated children against hepatitis B (HBV) may begin activities as healthcare sciences students (HSS), so, at the higher risk of HBV infection. Therefore, documenting their immunity at before training was recommended. To evaluate their immunity status, as well as measuring the presence of immunological memory and protection through administering 1-to-3 additional doses of HBV vaccine among HSS who have been immunized at childhood, this study was conducted.
 Subjects and Methods. The vaccination status of the accepted HSS was documented by reviewing their vaccination record card. HBV infection markers at before, and following 1-to3 dose of HBV vaccine were measured using ELISA. Simple descriptive statistical methods were used to analyze collected data.
 Results. Totally, 274 HSS, 59.1% female, with mean age 23.8 years were included. Of those, 228 in infancy, and 46 within last 12-years have been immunized. From 228 infantile immunized students,103 with 1-to-3 doses of HBV vaccine were vaccinated. Of 125 non-boosted HSS, 64 preserved their protective antibody titers. The proportion of protected students and their antibody levels were increased significantly and approached to 96.8% following 3-doses of booster injection.
 Conclusion. Nearly half of the vaccinated students had lost their protective antibody titers, but, the majority of them preserved their immunological memory, detected through anamnestic response to booster vaccination. To provide appropriate protection, universal vaccination with one-doses of HBV vaccine followed by serological monitoring to identify non-protected students for further management seems reasonable.

Assessment of Peste des Petits Ruminants Antibodies in Vaccinated Pregnant Ewes of Kazakh Breed Fine-Fleeced and Determination of the Decreasing Trend of Maternal Immunity in Their Lambs.

In this article, we first assessed peste des petits ruminants (PPR) antibodies in vaccinated pregnant ewes of Kazakh breed fine-fleeced immunized with the PPR vaccine and the duration of maternal immunity in their lambs. Ewes in the last trimester of pregnancy and gestation were immunized with a vaccine from the Nigeria 75/1 strain of the PPR virus (PPRV) produced by the Research Institute of Biological Safety Problems (RIBSP), Kazakhstan. Serum samples from lambs born from vaccinated and unvaccinated ewes were collected a week after birth and at intervals of 7 days for 18 weeks after birth. Serum samples collected from lambs were tested for PPR antibodies using competitive ELISA and virus neutralization test (VNT). Maternal antibodies (MAs) in lambs born from vaccinated ewes were detected for up to 18 weeks, with a tendency to decrease starting at week 14, and by the end of the experiment receded below the protective level (<1:8). In the blood serum of a 14-week-old lamb with MAs (1:8), post vaccination with a field dose (103 TCID50) of the vaccine against PPR, the titers of protective antibodies against PPRV increased to 1:16 on day 14 post vaccination, and the lamb was protected from infection with the field PPRV. A lamb of the same age with MAs in the 1:8 titer was 100% protected from infection with the field PPRV. Therefore, it is recommended that lambs of the Kazakh fine-wool breed be immunized from the age of 14 weeks or older to avoid a period of susceptibility.

The Effects of Bifidobacterium animalis Subsp. Lactis and Vitamin D on Immunological Response Following Vaccination in Puppies

Abstract This study aimed to determine the effects of oral application of Bifidobacterium animalis subsp. lactis and vitamin D on the immune response after vaccination in puppies. Crossbred dogs at the age of 55–65 days (n=21) of both sexes were grouped according to the application as follows: Group 1 - commercial polyvalent vaccine only (Vanguard 5L4, Zoetis); Group 2 -polyvalent vaccine and vitamin D; and Group 3 - polyvalent vaccine, B. animalis subsp. lactis, and vitamin D. The antibody titers, measured 3 weeks after the vaccination and after the 1st booster, demonstrated sufficient protective levels against the canine distemper virus but without significant difference between the groups when compare both values. No significant differences either, were observed in antibody titers against canine parvovirus after the initial vaccination. However, after the 1st booster, Group 2 samples showed significantly higher antibody titer value compared to the other groups (p&lt;0.05). In conclusion, the dogs included in this study had an adequate antibody response to canine parvovirus and distemper viruses following the vaccination and 1st booster in all three groups of animals, and significant increasing of protective antibody titers against canine parvovirus virus the after the 1st booster in the group where B. animalis subsp. lactis was included.

Persistence of maternal antibodies in calves born of combined foot-and-mouth disease + haemorrhagic septicaemia vaccinated buffaloes at organized dairy farm

Twelve apparently healthy and recently parturiated Murrah buffaloes, vaccinated with Foot-and-mouth disease (FMD) + Haemorrhagic septicaemia (HS) combined vaccine at an organized farm along with their newborn calves were inducted for detection of antibodies in serum and colostrum against FMD virus (FMDV) serotypes O, A and Asia-1, and Pasteurella multocida using enzyme linked immunosorbent assay. The calves born to vaccinated dams showed the presence of protective maternal antibody titre (≥1.8 log10) from birth till the period of study (16th week of age) against FMDV serotypes O, A and Asia-1. The maternal antibody titre against P. multocida were protective (≥1.8 log10) till fifth day of age which became partially protective thereafter till the period of study. It is recommended to avoid vaccination of the calves before 16th week of age with FMD+HS combined vaccine.

Enhancement of protective vaccine-induced antibody titer to swine diseases and growth performance by Amino-Zn, yucca extract, and β-mannanase feed additive in wean-finishing pigs.

The primary purpose of this research is to determine the effect of Amino-Zn (AZn), Yucca schidigera extract (YE), and β-mannanase enzyme supplementation on growth performance, nutrient digestibility, fecal gas emission, and immune response in pigs. A total of 180 crossbred pigs (6.57 ± 1 kg) were randomly assigned to one of three dietary treatments: CON-corn soybean meal (basal diet); TRT1-CON +1,000 ppm AZn + 0.07% yucca extract (YE) + 0.05% β-mannanase; and TRT2-CON +2,000 ppm AZn + 0.07% YE+ 0.05% β-mannanase for 22 weeks. Each treatment had 12 replicates with 5 pigs per pen. Pigs fed a diet supplemented with AZn, YE, and β-mannanase linearly increased (p < 0.05) BW and average daily gain at weeks 6, 12, 17, and 18. In contrast, the gain-to-feed ratio showed a linear increase (p < 0.05) from weeks 6 to 17 and the overall trial period. Moreover, the inclusion of experimental diets linearly decreased (p > 0.05) noxious gas emissions such as ammonia, hydrogen sulfide, acetic acid, carbon dioxide, and methyl mercaptans. The dietary inclusion of AZn, YE, and β-mannanase significantly increased the serological immune responses to Mycoplasma hyopneumoniae (MH) and foot-and-mouth disease virus (FMDV-O type) at the end of week 6 and porcine circovirus-2 (PCV-2) at week 19. Based on this result, we infer that the combination of AZn, YE, and β-mannanase supplement would serve as a novel in-feed additive to enhance growth performance and act as a boosting agent and immune stimulatory to increase the efficacy of swine vaccinations.