Significant Differences In Protection Research Articles

Efficacy of two vaccines against recent emergent antigenic variants of clade 2.3.2.1a highly pathogenic avian influenza viruses in Bangladesh

H5N1 highly pathogenic avian influenza viruses (HPAIVs) have caused outbreaks in poultry in Bangladesh since 2007. While clade 2.2.2 and 2.3.4.2 HPAIVs have not been detected since 2012, clade 2.3.2.1a viruses have caused continuous outbreaks since 2012 despite the use of vaccines. In this study, we evaluated the efficacy of two H5 vaccines licensed in Bangladesh, RE-6 inactivated vaccine, and a recombinant herpesvirus of turkeys vaccine with an H5 insert (rHVT-H5), for protection against recent field viruses in chickens. We selected three viruses for efficacy tests (A/chicken/Bangladesh/NRL-AI-3237/2017, A/crow/Bangladesh/NRL-AI-8471/2017 and A/chicken/Bangladesh/NRL-AI-8323/2017) from 36 H5 viruses isolated from Bangladesh between 2016 and 2018 by comparing the amino acid sequences at five antigenic sites (A-E) and analyzing hemagglutination inhibition (HI) titers with reference antisera. The RE-6 and rHVT-H5 vaccines both conferred 80–100% clinical protection (i.e. reduced morbidity and mortality) against the three challenge viruses with no significant differences in protection. In addition, both vaccines significantly decreased viral shedding from infected chickens as compared to challenge control chickens. Based on these metrics, the current licensed H5 vaccines protected chickens against the recent field viruses. However, the A/crow/Bangladesh/NRL-AI-8471/2017 virus exhibited antigenic divergence including: several unique amino acid changes in antigenic epitope sites A and B and was a serological outlier in cross HI tests as visualized on the antigenic map. The continuing emergence of such antigenic variants which could alter the dominant antigenicity of field viruses should be continuously monitored and vaccines should be updated if field efficacy declines.

Cross-protection conferred by immunization with an rOmpH-based intranasal fowl cholera vaccine

ABSTRACTA previous study demonstrated that a recombinant outer membrane protein H (rOmpH)-based intranasal fowl cholera vaccine elicited efficient homologous protection against the Pasteurella multocida strain X-73 (A:1) in chickens. The present study aimed to determine the cross-protectivity against heterologous P. multocida strains. The rOmpH was purified via electroelution and formulated with two kinds of adjuvants. The vaccine formulations in a total volume of 100 µl were 100 µg rOmpH with 3 µg of Escherichia coli enterotoxin B or 10 µg of CpG ODN2007. Chickens were assigned to three experimental groups depending on bacterial strain challenge exposure as well as three control groups. The chickens were immunized intranasally three times at three-week intervals. Challenge exposures were conducted by inoculation with homologous strain X-73 or heterologous strains P-1059 (A:3) or P-1662 (A:4) at four weeks after the final immunization. The specific antibody against rOmpH was produced in vaccinated birds. Sera IgY and secretory IgA antibody titres were significantly increased (P < 0.05) post-immunization. The stimulation index values of the vaccinated groups were significantly different from stimulation index values of the non-vaccinated groups (P < 0.05). Chicken survival rates after exposure to avian P. multocida strains ranged from 70% to 100%. There was no significant difference in protection between two kinds of adjuvants in vaccine formulations. Statistical analysis indicated no significant differences in protection among avian P. multocida strains challenge exposure. We conclude that an in-house rOmpH-based intranasal fowl cholera vaccine produced efficient cross-protectivity against heterologous strains of P. multocida.

Field vaccinated chickens with low antibody titres show equally insufficient protection against matching and non-matching genotypes of virulent Newcastle disease virus

Newcastle disease (ND) is a severe threat to the poultry industry and is caused by virulent strains of Newcastle disease virus (NDV). Many countries maintain a vaccination policy, but NDV is rapidly evolving as shown by the discovery of several new genotypes in the last decades. We tested the efficacy of the currently used classical commercial ND vaccine based on the genotype II strain VG/GA, applied under standard field conditions, against outbreak strains. Field vaccinated broilers were challenged with four different viruses belonging to genotype II, V or VII. A large proportion of field vaccinated broilers showed suboptimal immunity and the protection level against early and recent NDV isolates was dramatically low. Furthermore, there were no significant differences in protection afforded by a genotype II vaccine against a genotype II virus challenge compared to a challenge with viruses belonging to the other genotypes. This study suggests that the susceptibility of vaccinated poultry to NDV infection is not the result of vaccine mismatch, but rather of poor vaccination practices.

An Underappreciated Dimension of Human Trafficking: Battered and Trafficked Women and Public Policy

Both domestic violence and trafficking in humans pose serious problems worldwide. However, there are differences in the ways in which battered immigrant women and trafficked immigrant women are responded to by governmental agencies in Greece and in the USA. Trafficking in humans has been securitized, that is, framed as an issue linked to international security risk. As such, countries that do not take legal action to stop human trafficking could face US sanctions such as loss of United States military and economic assistance. Under significant international pressure, Greece, since 2002, passed a law that criminalized trafficking in humans and took necessary steps for providing protection and assistance to trafficked victims. Nevertheless, domestic violence and battered women remain silent in Greek society, and the availability of services to victims of domestic violence has eroded. We argue that, due to different issue framing of victims of trafficking and battered women, the connection of trafficking in humans to national security fosters different legal protection outcomes. The comparison of battered immigrant women and trafficked victims between Greece and the USA reveals significant differences in protection of battered immigrant women in the Organization for Economic Cooperation and Development (OECD) area. This article elucidates why there are public policy differences within OECD states that all grant a priority to prevention of human trafficking.

Influence of a reovirus-antibody complex vaccine on efficacy of Marek's disease vaccine administered in ovo.

Two experiments determined the influence of an experimental reovirus-antibody complex vaccine on Mareks disease virus (MDV) vaccine when used in ovo. Designs were the same except that specific-pathogen-free (SPF) broiler eggs were used in Experiment 1 and commercial broiler eggs with maternal antibodies against reovirus were used in Experiment 2. At 18 days of incubation, embryos were separated into four groups and inoculated with either diluent, MDV vaccine, reovirus-antibody complex vaccine, or a combination of reovirus-antibody complex and MDV vaccine. At 5 days of age, half the chickens in each group were challenged with MDV. At 7 wk old, all were euthanatized, weighed, and examined. At 7 days of age, remaining chickens in each group were challenged with reovirus. At 21 days old, chickens were euthanatized and weighed. No vaccine adversely affected hatchability or posthatch mortality in SPF or commercial chickens. There were no significant differences in protection against reovirus challenge when vaccines were used separately or in combination, and lesion scores were nearly identical in all vaccinated groups in both experiments. However, percentage of protection against reovirus was lower in Experiment 2, indicating an adverse effect of maternal immunity on efficacy of the reovirus vaccine. There were no significant differences in protection against MDV when the vaccines were used separately or combined. Severity of MDV lesions was nearly identical in all vaccinated groups in both experiments. However, the combination of vaccines gave numerically lower protection against MDV than MDV vaccine alone. Use of a larger number of birds, as in field conditions, may result in statistically lower protection for the vaccine combination. Large field trials are needed to determine the potential of the reovirus-antibody complex vaccine.

Vaccination against leprosy at Ben San Leprosy Centre, Ho Chi Minh City, Vietnam

Three vaccines, BCG alone, BCG+10 7 killed Mycobacterium vaccae and 10 8 killed M. vaccae alone, were studied in children living in close contact with leprosy. In the year before vaccination, 14/446 (3.1%) children had developed leprosy. Among those who were not vaccinated, 9/74 (12.2%) developed the disease in the first 4 years of the study and 5/65 (7.7%) developed the disease in the second 4 years. In comparison with this, among those vaccinated, 20/343 (5.8%) developed leprosy in the first 4 years and 5/323 (1.5%) developed leprosy in the second 4 years. This represents 52.5% protection in the first 4 years and 80.5% in the second 4 years. There were no significant differences in protection afforded by each of the three vaccines but the success of the killed preparation of M. vaccae is an important finding.

Protection of cattle against Fasciola hepatica infection by vaccination with glutathione S-transferase

Glutathione S-transferase (GST) from the liver fluke Fasciola hepatica was assessed as a vaccine immunogen in cattle in a number of immunological adjuvants. Significant reductions in fluke burdens (49–69%) were only observed in cattle vaccinated with GST in Quil Alsqualene Montanide® (SM) and PLG microspheres in SM but there was no correlation between anti-GST IgG titres and protection. In separate experiments, animals vaccinated with GST in Quil A/SM were still significantly protected (48%, P<0.05) 6 months after boosting and no significant differences in protection were seen when the metacercarial challenge was given over 1 month instead of as a single bolus. Inhibition of GST enzyme activity in vitro by cattle antisera did not correlate with reduced fluke burdens.

Deposition and properties of carbon-based amorphous protective coatings

Using a combination of temperature-humidity testing in D 2O vapour with secondary ion mass spectrometry (SIMS) depth profiling of deuterium, it has been demonstrated that moisture-tight coatings can be grown from acetylene, tetramethylsilane (TMS) and hexamethyldisiloxane (HMDSO) in an r.f. plasma deposition process, if a sufficient flux of energetic ions to the substrate surface is provided by the self-bias voltage at the substrate electrode. Using electrochemical impedance spectroscopic (EIS) investigations on films deposited on steel substrates, significant differences in protection of the substrates against corrosion in aerated electrolyte solution were found for films grown from TMS and HMDSO, respectively. Films deposited from TMS were usually stable for a period of time up to 300 h before localised corrosion began. One sample was completely stable over the whole measuring time of 460 h. Films deposited from HMDSO, however, immediately formed ionic current paths, as revealed by changes in EIS after only 24 h, and the characteristic appearance of the 0 h spectra. These results show that very good corrosion protection can be achieved by properly deposited amorphous hydrogenated silicon carbon (a-SiC:H) films, if film defects are carefully avoided.

Effects of potassium aluminium sulphate (alum) used in an Aeromonas salmonicida bacterin on Atlantic salmon, Salmo salar L.

Abstract. Potassium aluminium sulphate (alum) was tested for use as an adjuvant in an Aeromonas salmonicida bacterin injected into Atlantic salmon, Salmo salar L. Potential side‐effects of visceral adhesions, diminished growth and toxicity, as well as adjuvant effects, were examined. Both alum and the bacterin alone induced inflammation and adhesion formation when injected into the peritoneal cavity. When bacterin and alum were combined, these effects were compounded. Growth was not affected by any of the injected treatments. The acute toxicity of the bacterin was reduced from 33.7 to 0.3% mortality by the addition of alum. Alum appeared to enhance protection against challenge, but there were no statistically significant differences in protection between injecting bacterin alone or injecting bacterin with alum.

Efficacy of Live Vaccines against Serologic Subtypes of Infectious Bursal Disease Virus

Experiments determined the efficacy of live vaccines in specific-pathogen-free broilers against serologic subtypes of infectious bursal disease virus (IBDV). Challenge isolates were the Delmarva variant E, a standard serotype I (APHIS) and a variant isolate from Mississippi. The vaccines were a cloned standard (CS) vaccine (Clone Vac-D78), a cloned variant (CV) vaccine (Bursa Vac IV), and an uncloned standard (UCS) vaccine (Bursine II). The severity of microscopic lesions was correlated with bursal atrophy as measured by bursa-weight-to-body-weight ratios. All vaccines provided adequate protection against the APHIS challenge. The three vaccines averaged 77% protection against APHIS in the first experiment and 78% in the second. Protection against the variant E and Miss isolates was considerably less for all vaccines. The three vaccines produced an average 70% protection against the Miss isolate in the first experiment and 69% in the second experiment. Against the variant E virus, the three vaccines averaged 67% protection in the first experiment and 65% in the second. There were significant differences in protection for each vaccine against individual IBDV subtypes. Results showed that no vaccine provided good protection (at least 80%) against all three subtypes of IBDV.

Transfer of resistance with syphilitic immune cells: lack of correlation with mitogenic activity.

Hamsters infected intradermally with Treponema pallidum Bosnia A develop extensive chronic skin lesions, usually accompanied by metastatic lesions involving the paws, lips, and anal region and by lymph nodes teeming with treponemes. Throughout the course of syphilitic infection, cells from the inguinal lymph nodes responded poorly to stimulation with suboptimal, optimal, or supraoptimal concentrations of concanavalin A, phytohemagglutinin P, or lipopolysaccharide. The response of syphilitic spleen cells was variable. Depression of lymphocyte reactivity to mitogens preceded clinical signs of infection and correlated well with the chronicity of syphilitic infection. When syphilitic hamsters were treated with a curative dose of penicillin, their mitogenic responses returned to normal or were slightly elevated. No correlation existed between mitogenic activity and the ability of lymphoid cells to induce an effective immune response when transferred to normal recipients. No significant differences in protection were detected among recipients of immune cells with or without activity to mitogens. These results demonstrate that lymphocyte transformation by mitogens in vitro is not a measure of effective treponemicidal activity and so may not be a valid indicator of the protective immune status of syphilitic animals.

Control of Tobacco Budworm on Flue-Cured Tobacco with Insecticides Applied Mechanically12

Field experiments on flue-cured tobacco were conducted in North Carolina during 1964--69 to determine the effects of certain treatment variables on control of Heliothis virescens (F.) with insecticides applied mechanically. No significant differences in crop protection were found among (I) treatments of 0.75 pounds per acre of endosulfan and 1.5 pounds of carbaryl, DDT, and TDE; (2) 0.75-, 1.5-, and 3.0-pound rates of TDE; (3) wettable powder, emulsifiable concentrate, ultra-low volume, dust, and bait formulations of TDE; (4) electrostatic and conventional applications of TDE spray and dust, and (5) times of the day when TDE was applied. Significant differences in protection were found with respect to (I) the volume (4 vs. 100 gallons per acre) of TDE spray used, (2) the pressure (5 vs. 150 pounds per square inch) at which TDE spray was applied. (3) the spray angle (15 vs. 55°) used to apply TDE, and (4) the age (2 VS. 7 days) of larvae at the time TDE was applied. Better protection was obtained when applications were directed against 2-day-old larvae, and high volume, high pressure, or narrow spray angle increased this protection. However, protection with the better combinations of volume, pressure, and spray angle seldom exceeded 66%.