Measurement Of Antibody Titers Research Articles

New Guidance Clarifies Use of Pneumococcal, Influenza Vaccines in Older Adults

New Guidance Clarifies Use of Pneumococcal, Influenza Vaccines in Older Adults

Evaluation of Echinacea Immunomodulatory Effect on the Immune Response of Broiler Chickens

Immunomodulators provide an excellent approach as they mainly have fewer side effects than chemical drugs and have no affinity for creating microbial resistance. In order to investigate the Echinacea immunomodulatory effect on the immune response of broiler chickens,one hundred twenty (1-day-old) chicks of both sexes were randomly allocated into 2 dietary groups on floor pen (60 chicks/group), group1: Chicks were offered basal diets and kept as control group, group2: Chicks were offered basal diets supplemented with Echinacea purpurea (5gm/kg diet for 6 weeks). Evaluating the effects of Echinacea purpurea on growth performance, Serum Protein profile, total and differential leucocytic count, humeral immunity which was carried out by measuring antibody titer against Newcastle (ND) and (AIV) Avian Influenza vaccine, and on innate immunity which was carried by measuring some function of peripheral blood monocyte (PBM) as phagocytic activity, fungicidal activity, nitric oxide NO production and reactive oxygen species ROS production. Challenge test was carried out using virulent E. coli strain. The results revealed that, Echinacea improve growth performance, significantly increase antibody titer against ND and AIV vaccine as well as enhance the innate immunity by increasing the phagocytic activities, fungicidal activities, ROS production and nitric oxide production of monocytes. In challenge test,Echinacea reduce E. coli lesions, morbidity and mortality rate. Based on the results of this study, it could be concluded that growth performance and both humeral and innate immune responses of broiler chicks were improved by of dietary supplementation of Echinacea purpurea (5 g/kg diet), also it could protect broiler chickens from virulent E. coli infection.

Evaluation of Lactoferrin Immunomodulatory Effect on the Immune Response of Broiler Chickens

Immunomodulators are substances that able to regulate or modulate immune responses. In order to investigate the lactoferrin effect on the immune system of broiler chickens,one hundred twenty (1-day-old) chicks of both sexes were randomly allocated into 2 dietary groups (60 chicks/group), group1 (G1): chicks were offered basal diets and kept as control group, group2 (G2): Chicks were offered basal diets supplemented with lactoferrin (250mg/kg diet for 6 weeks). Evaluating the effects of dietary supplementation with lactoferrin on growth performance of broiler chicks, humeral immunity by measuring antibody titer against Newcastle (ND) and Avian influenza (AIV)vaccine, and on innate immunity by measuring some functions of peripheral blood monocytes (PBM) as phagocytic activity, fungicidal activity, nitric oxide (NO) production and reactive oxygen species (ROS) production by tetrazolium reduction test. To study antibacterial effect of lactoferrin, challenge test was carried out using virulent E. coli strain .The results revealed that, lactoferrin improve growth performance and could stimulate the humeral immunity by increasing the antibody titer aginst ND and AIV vaccine .Also lactoferrin could enhance the innate immunity by significant increasing of phagocytic and Fungicidal activities of PBM and its production of ROS and NO. Lactoferrin have the ability to protect broiler chickens from virulent agents as E. coli. Therefore, lactoferrin may be used as immunostimulant, growth promoters and antibacterial agent in broiler chickens.

Optimizing the process of inactivating influenza virus subtype H9N2 by formalin in the production of killed avian influenza vaccine

Avian influenza is one of the most important diseases in avian industry, which also threats human population. Thus, vaccination is necessary for controlling this viral disease. In this study, killed vaccine of avian influenza subtype H9N2 and formalin solution (for virus inactivation) were used. It is necessary to study the effect of different factors such as formalin concentration, as well as incubation temperature and duration on inactivation process. For this purpose, after preparation and measurement of antibody titers of vaccinal strains of avian influenza, 27 experimental samples of H9N2 avian influenza virus were prepared at different formalin concentrations (0.1%, 0.05%, and 0.025%), at different incubation temperatures (4 °C, 25 °C, and 37 °C), and in different incubation durations (12, 18, and 24 h). In addition, three control samples were prepared at three different test temperatures without adding formalin. All the samples were evaluated by inactivation test, hemagglutination assay, and measurement of free formaldehyde. All the experiments were repeated within three consecutive periods. Considering the findings and destructive effects of long incubation durations at 37°C on antigens, the temperature of 25 °C was more suitable. Furthermore, the free formaldehyde amounts at different concentrations at 25 °C were slightly different in comparison with 37 °C. Therefore, formalin concentration of 0.1% at 25 °C completely inactivated the virus within 24 h and was proposed as the optimal condition.

Estimating serological immune response against Newcastle disease vaccine in Aseel, Kadaknath and White Leghorn chicken by haemagglutination inhibition test

The present study aimed to estimate serological immune response against Newcastle disease vaccine investigating70 Aseel, 75 Kadaknath and 85 White Leghorn chicks. The day-old chicks were vaccinated with a dose of 106.5EID50 of RDF1 strain through occulo-nasal route followed by a booster dose on 28th day. The sera collected on 7,14, 21, 28, 35 and 42 days post-immunization (dpi) were used to measure antibody titres through haemagglutinationinhibition test. The data were analyzed by analysis of variance using SPSS 16.0 statistical software. The corresponding mean antibody titre (log2) estimates were 8.10±0.22, 7.89±0.18, 7.92±0.16, 8.29±0.14, 8.40±0.16 and 8.94±0.19 in Aseel, 7.32±0.16, 7.74±0.13, 7.56±0.13, 7.86±0.17, 8.43±0.17 and 9.14±0.16 in Kadaknath, and 8.48±0.28,8.02±0.31, 8.29±0.33, 8.14±0.30, 7.68±0.29 and 7.73±0.29 in White Leghorn chicken. The estimates significantlyvaried among different dpi in Aseel and Kadaknath chicken except White Leghorn. Aseel and Kadaknath chickendemonstrated gradual increasing trend and higher means of antibody titres for longer periods of dpi and achievedthe highest at 42 dpi, whereas White Leghorn chicken showed an irregular trend, the highest titre being observed at7 dpi. Again the 3 chicken genotypes significantly varied in antibody titres at 7, 35 and 42 dpi; White Leghornchicken demonstrated the highest antibody titre at 7 dpi, while Kadaknath chicken showed the highest titre at 35and 42 dpi. The higher and longer immune responsive Aseel and Kadaknath chicken might be utilized for selectiveintrogression of their candidate genes in high productive chicken germplasm with less NDV response.

Assessment of Embryo Fetal Developmental Toxicity Study of Hepatitis B (rDNA) Vaccine in Wistar Rats

Hepatitis B infection is one of the most deadly diseases causing acute as well as chronic infection to liver which globally affects 5% of people worldwide. A recently developed Hepatitis B vaccine by recombinant DNA technology has been shown to be potentially efficacious in prevention of Hepatitis B virus (HBV) mediated infection. The purpose of current study was to detect the adverse effects of the vaccine on the pregnant female rats and developing embryo/fetus during organogenesis exposure. If any. In addition, anti-HBV antibodies in pregnant females were measured during the study. Three groups of 25 females injected intramuscularly Hepatitis B (rDNA) vaccine at the dose level of 0.25, 0.5 and 1.0 mL per animal once prior to cohabitation and once during gestation (day 10). Concurrent placebo control group was maintained to differentiate the effects of placebo from vaccine related effects. All females were mated to males of same stock with mating ratio of 2:1. The pregnant females were C-section about one day prior to delivery i.e. GD 20 to evaluate the uterine contents and the fetuses for external, visceral and skeletal anomalies. There was no abortion or death during the study. Expected local effects like mid swelling at injection site was observed which was attributed to common placebo related non-adverse effect. Gravimetric parameters did not reveal evidence of vaccine related toxicity. Pre natal parameters were comparable to control. There was no evidence of prenatal developmental toxicity and based on the results Hepatitis B (r-DNA) vaccine was not a teratogenic during the study. Immunogenicity profile showed measurable antibody titer that supports the use of the vaccine in the targeted human population.

Characterization of a reproducible rat EAMG model induced with various human acetylcholine receptor domains

Myasthenia gravis (MG) is usually caused by antibodies against the muscle acetylcholine receptor (AChR). Experimental autoimmune MG (EAMG) is the animal model of MG, typically induced by immunization of rodents with AChR isolated from the electric organ of Torpedo californica. We have successfully induced EAMG in Lewis rats by immunization with the extracellular domains (ECDs) of the human AChR subunits (α, β, γ, δ and ε) expressed in yeast. Analysis of the antibody titers revealed a robust antigenic response against all the peptides, but a marked difference in their pathogenicity; the α subunit ECD was the most pathogenic, resulting in the highest percentage of affected animals. Measurements of antibody titers, electromyographic tests and quantitation of the muscle AChR content, offered further support to these findings. The EAMG models presented herein, could be used for studying subunit-specific pathogenic mechanisms, and, more importantly, as tools for the evaluation of antigen-specific therapeutic approaches, which rely on the human AChR.

Anti-heparan sulfate antibody and functional loss of glomerular heparan sulfate proteoglycans in lupus nephritis.

Background The purpose of this study was to evaluate the features of heparan sulfate proteoglycans (HSPGs) as agrins of the glomerular basement membrane (GBM) and circulating anti-heparan sulfate (HS) antibodies in lupus nephritis, comparing titers among the following groups: lupus nephritis (LN), non-renal lupus, non-lupus nephritis, and healthy controls. Methods The stage of nephritis was determined based on the kidney biopsy. Alcian blue staining and immunohistochemical (IHC) staining for agrin were performed for histological evaluation of GBM HSPGs in normal glomeruli, non-lupus membranous glomerulonephritis (MGN), and lupus MGN. The results were used for measurement of the serum anti-HS antibody titers using an enzyme-linked immunosorbent assay (ELISA) in the following groups: 38 healthy controls, 38 non-lupus nephritis, 37 non-renal lupus, and 38 LN. Results Glomerulus HSPGs were stained bluish-green along the GBM with Alcian blue. However, IHC staining against agrin was almost completely negative in the lupus MGN group compared with the normal and non-lupus MGN groups, which showed brown staining of GBM. A higher level of anti-HS IgG was detected in LN compared with other groups, respectively. Higher titers were associated with the presence of SLE and nephritis. A higher degree of proteinuria normalized to glomerular filtration rate (eGFR) was observed in association with higher anti-HS antibody titers in LN. Conclusion This study demonstrated a functional loss of GBM HSPGs and higher levels of circulating anti-HS antibodies as a characteristic feature of lupus nephritis, suggesting their involvement in the pathogenesis of lupus nephritis and proteinuria.

The priming effect of previous natural pandemic H1N1 infection on the immunogenicity to subsequent 2010-2011 influenza vaccination in children: a prospective cohort study

BackgroundThe effect of previous natural pandemic H1N1 (H1N1 pdm09) influenza infection on the immunogenicity to subsequent inactivated influenza vaccination in children has not been well studied. We aimed to evaluate the effect of H1N1 pdm09 natural infection and vaccination on the immunogenicity to subsequent 2010-2011 seasonal inactivated influenza vaccination in children.MethodsFrom October 2010 to May 2011, we conducted an open-label, multi-center study in children aged 6 months -18 years in Korea. We measured antibody titers with a hemagglutination-inhibition (HI) assay at baseline, 1 month, and 6 months after vaccination with trivalent split or subunit vaccines containing H1N1 pdm, A/H3N2, and B. The subjects were classified into 4 groups depending on the presence of laboratory-confirmed H1N1 pdm09 infection and/or vaccination in the 2009-2010 season; Group I: vaccination (-)/infection(-), Group II: vaccination (-)/infection(+), Group III: vaccination (+)/infection(-), Group IV: vaccination (+)/infection(+).ResultsAmong the subjects in group I, 47 subjects who had a baseline titer >1:10 were considered to have an asymptomatic infection. They were included into the final group II (n = 80). We defined the new group II as the infection-primed (IP) group and group III as the vaccine-primed (VP) group. Seroconversion rate (57.5 % vs 35.9 %, p = 0.001), seroprotection rate at 6 months after vaccination (70.8 % vs 61.8 %, p = 0.032), and GMT at 1 month after vaccination (129.9 vs 66.5, p = 0.002) were significantly higher in the IP group than in the VP group. In the 9–18 year-old group, seroconversion rate and immunogenicity at 1 and 6 months were significantly higher in the IP group than in the VP group. However in the 1–7 year-old age group, there was no significant difference between the two groups.ConclusionsPrevious H1N1 pdm09 infection appears to have positive effects on immunogenicity of subsequent inactivated influenza vaccines against H1N1 pdm09 in older children.

Non-Clinical Safety Assessment of Single and Repeated Administration of Hepatitis B (rDNA) Vaccine

Hepatitis B infection is an important public health concern all over the world. As no specific treatment is available, greatest emphasis is placed on prevention through immunization. A recently developed Hepatitis B (rDNA) vaccine, containing purified surface antigen of virus like particles derived from culturing genetically engineered Hansenula polymorpha yeast cells having the Hepatitis B surface antigen gene of Hepatitis B virus was evaluated to establish potential safety and tolerability of the Hepatitis B (rDNA) vaccine formulation. Non clinical safety assessment was evaluated as single dose studies in mice and rats and a repeat dose study in rats. No signs of acute toxicity were noted in mice and rats through clinical signs and gross necropsy examination. The local reactions observed in both the species at the injection site were attributed to the property of an adjuvanted vaccine. Similarly, the absence of systemic toxicity was evaluated after repeated administrations in the rat. In repeated dose study, additionally histiocytosis and/or lymphoid hyperplasia at femoral lymph node were observed. The incidences of such local effects were considered as innate immune response generated against the vaccine antigens and enhanced by the adjuvants. The vaccine was shown to be well tolerated without any obvious signs of adverse systemic toxicity, with findings largely attributable to the adjuvant used. The immunogenicity profile showed measurable antibody titer. Therefore, in these non-clinical models, the single and repeated dose administrations of Hepatitis B (rDNA) vaccine were considered as well tolerated up to absolute human dose (1 ml).

Relative Contribution of Dengue IgG Antibodies Acquired during Gestation or Breastfeeding in Mediating Dengue Disease Enhancement and Protection in Type I Interferon Receptor-Deficient Mice.

Dengue virus (DENV) causes a spectrum of diseases ranging from self-limiting dengue fever to severe conditions such as haemorrhagic fever and dengue shock syndrome. Antibody-dependent enhancement (ADE) is thought to explain the occurrence of severe dengue whereby pre-existing binding but non-neutralising antibodies enhance DENV infection. The ADE phenomenon is supported by epidemiological findings that infants that born to dengue immune mothers are at greater risk to develop severe dengue upon primary infection. The role of maternally acquired dengue-specific antibodies in disease enhancement was recently recapitulated in a mouse model where mice born to DENV1-immune mothers experienced enhanced disease severity upon DENV2 infection. Here, this study investigates the relative contribution of maternal dengue-specific antibodies acquired during gestation and breastfeeding in dengue disease. Using a surrogate breastfeeding mother experimental approach, we showed that majority of the maternal dengue-specific antibodies were acquired during breastfeeding and conferred an extended enhancement window. On the other hand, in the context of homologous infection, breastfeeding conferred protection. Furthermore, measurement of dengue-specific antibody titres over time in mice born to dengue immune mothers revealed a biphasic pattern of antibody decay as reported in humans. Our work provides evidence of the potential contribution of breast milk-acquired dengue-specific IgG antibodies in enhancement and protection against dengue. Should such contribution be established in humans as well, it may have important implications for the development of guidelines to dengue-immune breastfeeding mothers.

Free-Roaming Dogs in Nepal: Demographics, Health and Public Knowledge, Attitudes and Practices.

In Nepal, most dogs are free to roam and may transmit diseases to humans and animals. These dogs often suffer from malnutrition and lack basic health care. Minimal information is available about their demographics and about public attitudes concerning dogs and diseases. We carried out a study in Chitwan District (central Nepal), to collect baseline data on free-roaming owned dog demographics, assess knowledge, attitudes and practices of dog owners concerning dogs and rabies, evaluate rabies vaccination coverage and anthelmintic treatment of dogs, measure dogs' response to rabies vaccination and assess dog health through body condition scores and parasites. We conducted household interviews with owners of free-roaming female dogs (n=60) and administered dogs with rabies vaccination and anthelmintics. Dog owners regularly fed free-roaming dogs but provided minimal health care; 42% of respondents did not claim ownership of the dog for which they provided care. We collected skin, faecal and blood samples for parasite identification and for measuring rabies virus-specific antibodies. Ninety-two per cent of dog owners were aware of the routes of rabies virus transmission, but only 35% described the correct post-exposure prophylaxis (PEP) following a dog bite. Twenty-seven per cent of the dogs had measurable rabies virus-specific antibody titres and 14% had received anthelmintics in the previous year. Following rabies vaccination, 97% of dogs maintained an adequate antibody titre for ≥6months. Most dogs appeared healthy, although haemoprotozoans, endoparasites and ectoparasiteswere identified in 12%, 73% and 40% of the dogs, respectively. Poor skin condition and parasite load were associated. Seventy-four per cent of the females had litters in 1year (mean litter size=4.5). Births occurred between September and February; we estimated 60% mortality in puppies. We concluded that vaccination coverage, PEP awareness and anthelmintic treatment should be emphasized in educational programmes focussed on animal welfare, veterinary and public health.

Validation of an Optimized ELISA for Quantitative Assessment of Epstein-Barr Virus Antibodies from Dried Blood Spots

ABSTRACTOur objective was to validate a commercially available ELISA to measure antibody titers against Epstein-Barr virus (EBV) in dried blood spots (DBS) to replace a previously validated assay for DBS that is no longer available. We evaluated the precision, reliability, and stability of the assay for the measurement of EBV antibodies in matched plasma, fingerprick DBS, and venous blood DBS samples from 208 individuals. Effects of hematocrit and DBS sample matrix on EBV antibody determination were also investigated, and the cutoff for seropositivity in DBS was determined. A conversion equation was derived to enable comparison of results generated using this method with the former DBS method. There was a high correlation between plasma and DBS EBV antibody titers (R2 = 0.93) with very little bias (−0.07 based on Bland-Altman analysis). The assay showed good linearity and did not appear to be affected by the DBS matrix, and physiological hematocrit levels had no effect on assay performance. There was reasonable agreement between DBS EBV titer estimates obtained using this assay and the previously validated assay (R2 = 0.72). The commercially available ELISA assay for EBV antibody titers that we validated for use with DBS will facilitate continued investigation of EBV antibody titers in DBS.

Quantifying homologous and heterologous antibody titre rises after influenza virus infection.

Most influenza virus infections are associated with mild disease. One approach to estimate the occurrence of influenza virus infections in individuals is via repeated measurement of humoral antibody titres. We used baseline and convalescent antibody titres measured by haemagglutination inhibition (HI) and viral neutralization (VN) assays against influenza A(H1N1), A(H3N2) and B viruses to investigate the characteristics of antibody rises following virologically confirmed influenza virus infections in participants in a community-based study. Multivariate models were fitted in a Bayesian framework to characterize the distribution of changes in antibody titres following influenza A virus infections. In 122 participants with PCR-confirmed influenza A virus infection, homologous antibody titres rose by geometric means of 1·2- to 10·2-fold after infection with A(H1N1), A(H3N2) and A(H1N1)pdm09. Significant cross-reactions were observed between A(H1N1)pdm09 and seasonal A(H1N1). Antibody titre rises for some subtypes and assays varied by age, receipt of oseltamivir treatment, and recent receipt of influenza vaccination. In conclusion, we provided a quantitative description of the mean and variation in rises in influenza virus antibody titres following influenza virus infection. The multivariate patterns in boosting of antibody titres following influenza virus infection could be taken into account to improve estimates of cumulative incidence of infection in seroepidemiological studies.

P507. Clinical role, optimal timing and frequency of measurement of serum infliximab levels and anti-infliximab antibody titres in patients with inflammatory bowel disease

P507. Clinical role, optimal timing and frequency of measurement of serum infliximab levels and anti-infliximab antibody titres in patients with inflammatory bowel disease

Results of Booster Vaccination in Children with Primary Vaccine Failure after Initial Varicella Vaccination

In October 2014, the varicella vaccination policy in Japan was changed from a single voluntary inoculation to two routine inoculations. This paper reports the results of booster vaccination in children who did not show seroconversion after initial vaccination (i.e., primary vaccine failure : PVF) over a 7-year period prior to the introduction of routine varicella vaccination. Between November 2007 and May 2014, 273 healthy children aged between 1.1 and 14.5 years (median : 1.7 years) underwent varicella vaccination. Before and 4 to 6 weeks after vaccination, the antibody titers were measured using an immune adherence hemagglutination (IAHA) assay and a glycoprotein-based enzyme-linked immunosorbent assay (gpELISA). In addition, side reactions were examined during the four-week period after vaccination. Children who did not show IAHA seroconversion (PVF) were recommended to receive a booster vaccination, and the measurement of antibody titers and an assessment of side reactions were performed after the booster dose. In May 2015, a questionnaire was mailed to each of the 273 participants to investigate whether they had developed varicella and/or herpes zoster after vaccination. After initial vaccination, the IAHA seroconversion rate was 75% and the mean antibody titer (Log2) with seroconversion was 4.7, while the gpELISA seroconversion rate was 84% and the mean antibody titer (Log10) with seroconversion was 2.4. Among children with PVF, 54 received booster vaccination within 81 to 714 days (median : 139 days) after the initial vaccination. After booster vaccination, the IAHA seroconversion rate was 98% and the mean antibody titer (Log2) with seroconversion was 5.8. Both the seroconversion rate and the antibody titer were higher compared with the values after the initial vaccination (p < 0.01). After booster vaccination, the gpELISA seropositive rate was 100% and the mean positive antibody titer (Log 10) was 3.6 ; similar results were obtained for the IAHA assay, with a significantly higher, antibody response than that after the initial vaccination (p < 0.01). Side reactions were generally minor, including fever (≥ 37.5 degrees C), rash at the injection site, and rash at other sites. There were no significant differences in the incidences of side reactions between the initial and booster vaccinations. A total of 185 participants responded to the questionnaire (response rate : 68%), and the period between receiving the initial vaccination and their response to the questionnaire ranged from 1.0 to 7.5 years (median : 4.0 years). The prevalence of breakthrough varicella after the initial vaccination was 17% among seroconverters who did not receive booster vaccination and 14% among non-seroconverters who received booster vaccination, showing no significant difference between the two groups. In conclusion, there are no safety issues regarding the administration of a booster vaccination to children with PVF after an initial varicella vaccination, and,a good antibody response can be expected.

Factors affecting the immunogenicity of the live attenuated influenza vaccine produced in continuous cell line

ABSTRACT The biological basis for the restricted immunogenicity of some live attenuated influenza vaccine strains generated on the backbone of the cold adapted (ca) A/Singapore/1/1957/ca (H2N2) influenza A virus master strain and produced in the Vero cells was investigated. According to our previous results the vaccine candidate made from A/Hong Kong/1035/1998 (H1N1) Vero-derived virus did not provoke a measurable antibody titers following the intranasal immunization of humans. We report here that the hemagglutinin (HA) of A/Hong Kong/1035/1998 virus contained the mutation 10Ile→Val in the HA2 subunit, that increased the pH threshold of HA conformational change (pH of activation) by 0.3 pH units and therefore might be responsible for the lack of immune response in humans. Similar effect was shown for the reassortant made from the Vero-derived A/Switzerland/5389/1995 (H1N1) (5389wt) virus which had the HA2 mutation 3Phe→Leu leading to the lack of immune response in mice. Another factor compromising the immunogenicity of a vaccine candidate is the incompatibility of epidemic virus HA with the M gene of the master strain. In mice the 6/2 A/Switzerland/5389/1995 reassortant induced antibodies that were directed predominantly to the HA2 subunit and were detectable by ELISA but not by a hemagglutination inhibition (HAI) test. In contrast, the 5/3 reassortant, bearing the HA, neuraminidase (NA), and M genes from the epidemic virus induced an equivalent amount of antibodies against the HA1 and HA2 subunits detected by HAI and ELISA. By comparing the sensitivity of the viruses to amantadine, we showed that the M2 ion channel of the master strain had lower activity than that of the A/Switzerland/5389/1995. These data suggest that M2 of the master strain was not sufficiently active to keep the pH of the trans- Golgi network high enough to prevent the conformational change of the acid sensitive HA to the low pH form. Overall, the adaptation mutations in the HA of the vaccine candidate that increase the pH of HA activation as well as the incompatibility of HA and M genes must be taken into consideration when constructing the reassortant strains for the live attenuated vaccine.

Evaluation of kefir as a potential probiotic on growth performance, serum biochemistry and immune responses in broiler chicks.

This experiment was conducted to evaluate the effect of milk or molasses kefir as a probiotic on growth performance, carcass traits, serum biochemistry and humoral immune responses in broiler chickens. A total of 192 one-d-old as hatched broiler chicks (Ross 308) were randomly allotted to 4 treatments, each with 4 replicate pens of 12 chicks. The following treatments were applied: 1) a basal diet (C) and normal drinking water, 2) 2% milk kefir in drinking water, 3) 2% molasses kefir in drinking water, and 4) the diet C supplemented with commercial probiotic. At d 42, eight birds per treatment were killed for determination of carcass traits. Broilers at 28 days of age were bled for measuring antibody titers against Newcastle disease virus (NDV) and avian influenza virus (AIV), at 30 days of age for antibody titers against sheep red blood cell (SRBC), and at 42 days of age for biochemical analysis. Supplementing 2% milk kefir increased body weight of broilers at 28 and 42 days of age (P < 0.05). Supplementing 2% molasses kefir improved feed conversation ratio (FCR) of broilers during growth period (P < 0.05), but FCR of broilers in other periods was not affected. Daily feed intake, internal organ weights, and carcass traits were not influenced by the treatments except for small intestine and ceca length. Small intestinal length significantly decreased in broilers supplemented with milk and molasses kefir (P < 0.05). Molasses kefir supplementation significantly (P < 0.05) increased antibody titer against SRBC at 31 days of age but other immune related parameters were not statistically different among treatments. Biochemical parameters including serum protein, albumin, and triglyceride concentrations were not statistically (P > 0.05) influenced. Broilers supplemented with molasses kefir, had a significantly lower concentration of serum total cholesterol, low density lipoprotein cholesterol and elevated high density lipoprotein cholesterol at 42 days of age (P < 0.05). In conclusion, the results indicated that inclusion of 2% milk kefir in drinking water would improve growth performance of broiler chickens.

Efficacy and immunogenicity of high-dose influenza vaccine in older adults by age, comorbidities, and frailty

BackgroundA randomized trial demonstrated that a high-dose inactivated influenza vaccine (IIV-HD) was 24.2% more efficacious than a standard-dose vaccine (IIV-SD) against laboratory-confirmed influenza illness in adults ≥65 years. To evaluate the consistency of IIV-HD benefits, supplemental analyses explored efficacy and immunogenicity by baseline characteristics of special interest. MethodsDouble-blind, randomized, active-controlled, multicenter trial. Adults ≥65 years were randomized 1:1 to receive IIV-HD or IIV-SD and followed for 6–8 months postvaccination for the occurrence of influenza. One third of participants were randomly selected to provide sera for measurement of hemagglutination inhibition antibody (HAI) titers. Efficacy (IIV-HD vs. IIV-SD) against laboratory-confirmed, protocol-defined influenza-like illness (PD-ILI) and HAI geometric mean titer (GMT) ratios (IIV-HD/IIV-SD) were evaluated by age, and number of high-risk comorbid and frailty conditions. ResultsEfficacy (95% confidence intervals) of IIV-HD relative to IIV-SD against laboratory-confirmed PD-ILI was 19.7% (0.4%; 35.4%) for participants 65–74 years, 32.4% (8.1%; 50.6%) for those ≥75 years, 22.1% (3.9%; 37.0%) for participants with ≥1 high-risk comorbidity, 23.6% (−3.2%; 43.6%) for those with ≥2 high-risk comorbidities, 27.5% (0.4%; 47.4%) for persons with 1 frailty condition, 23.9% (−9.0%; 47.2%) for those with 2 frailty conditions, and 16.0% (−16.3%; 39.4%) for those with ≥3 frailty conditions. There was no evidence of vaccine efficacy heterogeneity within age, comorbidity, and frailty strata (P-values 0.351, 0.875, and 0.838, respectively). HAI GMT ratios were significantly higher among IIV-HD recipients for all strains and across all subgroups. ConclusionsEstimates of relative efficacy consistently favored IIV-HD over IIV-SD. There was no significant evidence that baseline age, comorbidity, or frailty modified the efficacy of IIV-HD relative to IIV-SD. IIV-HD significantly improved HAI responses for all strains and in all subgroups. IIV-HD is likely to provide benefits beyond IIV-SD for adults ≥65 years, irrespective of age and presence of comorbid or frailty conditions.

Immunization of Mice with Anthrax Protective Antigen Limits Cardiotoxicity but Not Hepatotoxicity Following Lethal Toxin Challenge.

Protective immunity against anthrax is inferred from measurement of vaccine antigen-specific neutralizing antibody titers in serum samples. In animal models, in vivo challenges with toxin and/or spores can also be performed. However, neither of these approaches considers toxin-induced damage to specific organ systems. It is therefore important to determine to what extent anthrax vaccines and existing or candidate adjuvants can provide organ-specific protection against intoxication. We therefore compared the ability of Alum, CpG DNA and the CD1d ligand α-galactosylceramide (αGC) to enhance protective antigen-specific antibody titers, to protect mice against challenge with lethal toxin, and to block cardiotoxicity and hepatotoxicity. By measurement of serum cardiac Troponin I (cTnI), and hepatic alanine aminotransferase (ALT), and aspartate aminotransferase (AST), it was apparent that neither vaccine modality prevented hepatic intoxication, despite high Ab titers and ultimate survival of the subject. In contrast, cardiotoxicity was greatly diminished by prior immunization. This shows that a vaccine that confers survival following toxin exposure may still have an associated morbidity. We propose that organ-specific intoxication should be monitored routinely during research into new vaccine modalities.