HI Antibody Research Articles

The Inducing Roles of the New Isolated Bursal Hexapeptide and Pentapeptide on the Immune Response of AIV Vaccine in Mice.

Bursa of Fabricius is the acknowledged central humoral immune organ. The bursal-derived peptides play the important roles on the immature B cell development and antibody production. Here we explored the functions of the new isolated bursal hexapeptide and pentapeptide on the humoral, cellular immune response and antigen presentation to Avian Influenza Virus (AIV) vaccine in mice immunization. The bursa extract samples were purified following RP HPLC method, and were analyzed with MS/MS to identify the amino acid sequences. Mice were twice subcutaneously injected with AIV inactivated vaccine plus with two new isolated bursal peptides at three dosages, respectively. On two weeks after the second immunization, sera samples were collected from the immunized mice to measure AIV-specific IgG antibody levels and HI antibody titers. Also, on 7th day after the second immunization, lymphocytes were isolated from the immunized mice to detect T cell subtype and lymphocyte viabilities, and the expressions of co-stimulatory molecule on dendritic cells in the immunized mice. Two new bursal hexapeptide and pentapeptide with amino acid sequences KGNRVY and MPPTH were isolated, respectively. Our investigation proved the strong regulatory roles of bursal hexapeptide on AIV-specific IgG levels and HI antibody titers, and lymphocyte viabilities, and the significant increased T cells subpopulation and expressions of MHCII molecule on dendritic cells in the immunized mice. Moreover, our findings verified the significantly enhanced AIV-specific IgG antibody and HI titers, and the strong increased T cell subpopulation and expressions of CD40 molecule on dendritic cells in the mice immunized with AIV vaccine and bursal pentapeptide. We isolated and identified two new hexapeptide and pentapeptide from bursa, and proved that these two bursal peptides effectively induced the AIV-specific antibody, T cell and antigen presentation immune responses, which provided an experimental basis for the further clinical application of the bursal derived active peptide on the vaccine improvement.

Experimental Co-infection of Low Pathogenic Avian Influenza Virus (H9N2) and Escherichia Coli in SPF Broiler Chickens.

The work was implemented to evaluate the pathogenicity of H9N2 when co-infected with the E.coli. Avian influenza H9N2 virus strain A/chicken/Egypt/1618F/2016 which was isolated from Luxor province during 2016 and E.coli serotype O78 were used in this research. Sixty SPF birds were divided into 6 groups of ten birds each. At age 21 days, group 1 was inoculated with H9N2 only, group 2 received E.coli and three days later received H9N2, group 3 inoculated with H9N2 and after three days received E.coli, group 4 was challenged with E.coli and H9N2 at the same time, group 5 was inoculated with E.coli only, and group 6 was designed as a negative group. Clinical signs, postmortem examination, and serological examination were monitored for 15 days. The H9N2 virus presence was assessed in tracheal and cloacal swabs using real-time PCR. The most severe signs and lesions were observed in groups (3, and 4), with also high mortality rate than other groups with a percentage of 20%. Groups 3, and 4 showed a longer duration in virus shedding in the tracheal and cloacal samples. The hemagglutination inhibition test, group 4 showed high HI antibody titer against AIV-H9N2 antigen than other groups, while group 2 showed the lowest HI antibody titer against AIV-H9N2 antigen than other groups that received only the H9N2 virus. In conclusion, the outcomes of this study revealed that the infection of H9N2 with E.coli can exacerbate the clinical outcomes and mortality rates which leads to higher economic losses in chicken flocks.

Comparative immune response and pathogenicity of the H9N2 avian influenza virus after administration of Immulant®, based on Echinacea and Nigella sativa, in stressed chickens

Avian influenza vaccines are commonly used in the poultry industry, and some medicinal plants can increase the efficacy of such vaccines. The objective of this study was to evaluate the effect of Immulant® (IMU) (a commercial product based on Echinacea and Nigella sativa) on stress induced by dexamethasone (DEX) in chickens vaccinated (VAC) against the H9N2 avian influenza virus (AIV-H9N2). Seven experimental groups were included: the negative control, VAC, DEX, VAC + DEX, VAC + DEX + IMU, VAC + IMU and IMU groups. The vaccinated chickens (at 10 days of age) were injected daily with DEX for three days pre-vaccination and for three days pre-challenge and orally administered 1% IMU for 6 weeks post-vaccination (PV). The chickens were then challenged intranasally with AIV-H9N2 at 28 days PV. Serum, blood, tracheal and cloacal swabs and tissue samples were collected in the 1st and 4th weeks PV and at different time points post-challenge. The results showed significant changes (P ≤ 0.05) in oxidative stress and antioxidant biomarkers (malondialdehyde, nitric oxide and reduced glutathione), haematological and immunological parameters, final live weights, relative organ weights and histopathological lesions between the VAC+DEX group and the VAC group. Moreover, IMU significantly increased protection rates post-challenge, HI antibody titers and heterophil phagocytic activity and decreased DEX-induced stress and virus shedding titers. In conclusion, oral administration of 1% IMU for six weeks can enhance the immune response after AI-H9N2 vaccination and reduce the pathogenicity of infection in stressed chickens.

Clinical evaluation, serological response and lesions generated by the A/Mexico/La Gloria-3/2009/H1N1 and A/swine/New Jersey/11/1976/H1N1 influenza viruses in colostrated and non-colostrated pigs.

Influenza A viruses cause respiratory disease in piglets, and maternal immunity plays an important role in protecting against Influenza virus infection. Nevertheless, in the presence of high levels of maternal antibodies against influenza, an adequate immune response is not developed. In this study, the effect of maternal antibodies against the swine influenza A/swine/New Jersey/11/1976/H1N1 virus (swH1N1) on clinical presentation, serological response, and lesions produced in colostrated and non-colostrated pigs was evaluated in pigs infected with the human influenza A/Mexico/La Gloria-3/2009/ H1N1 (pH1N1) and swH1N1 viruses. Our results indicated that between 2 and 4days post-challenge, sneezing and mild nasal discharge were observed in all pigs. Body temperature in pigs from all treatment groups ranged between 39.2 and 39.3°C. Pigs inoculated with the pH1N1 virus (421g) exhibited a significantly lower daily weight gain than those inoculated with the swH1N1 virus (524g). HI antibody titers against the pH1N1 virus were significantly different between colostrated (1.62) and non-colostrated (0.43) pigs. Significant differences in antibody titers were detected between pigs inoculated with the pH1N1 (1.28) or the swH1N1 virus (0.77) (P < 0.05). The highest percentage of pulmonary lesions was observed in non-colostrated/pH1N1 pigs (11.88%) at 6days post-challenge. Cross reactivity was observed between the pH1N1 and swH1N1 viruses, as the maternal antibodies against the swH1N1 virus successfully neutralized the pH1N1 virus infection.

Trials For Preparation And Evaluation Of Inactivated Tissue Culture Newcastle Disease Vaccine From Recent Isolate

The present study was undertaken to development of BHK-21 cell adapted inactivated vaccine of Newcastle disease virus (NDVgenotype VII) from the field isolate from broiler chicken in Egypt during 2015-2016. The isolatesof El-Giza/2015were classified by sequencing as velogenic NDV genotype VII d contains F protein cleavage site motifs (112RRQKRF117). Such virus was propagated in the BHK-21 cell line. and cell adapted virus was confirmed as NDV by reverse transcription-polymerase chain reaction (RT-PCR) using fusion gene-specific primers and used to develop inactivated vaccine adjuvanted with Montanide IMS 1313.Potency test revealed that Vaccinated chicks with 0.5ml of prepared NDV vaccine exhibited HI antibody titer of 8.6 log2 three weeks post vaccination with the highest titer (10.6 log2/ml) at the 6th-week post vaccination, and 3rd weeks post challenge test. Protective antibodies values were persisting till 12th weeks post vaccination. All chicken groups vaccinated with both prepared inactivated tissue culture vaccine using ISA 1313 and VSVRI inactivated ISA70 adjuvant vaccines were passed challenge test (97.5%,97%,96% protective efficiency to SPF chickens) against the isolated virulent NDV, while the control group could not provide any protective efficiency. The present study indicated that, BHK-21 cell adapted recent isolated NDV inactivated vaccine produced a satisfactory antibodies titre that efficient in control of the disease in Egypt.

Measurement of anti-influenza neuraminidase antibody induced by H7N9 influenza vaccine

Objective To develop an enzyme-linked lectin assay (ELLA) for measuring neuraminidase inhibition (NI) antibody titers in subjects vaccinated with H7N9 influenza vaccine. Methods Neuraminidase substrate, the dilution and incubation time of enzyme-labeled antibody, the concentration of influenza antigen for coating and pH value of the dilution buffer were optimized. Based on that, ELLA was established and used to detect anti-influenza neuraminidase antibody titers in serum samples of 34 subjects before and after vaccination with H7N9 influenza vaccine. Results The optimal neuraminidase substrate was fetuin at a coating concentration of 7.5 μg/ml. The optimal dilution of enzyme-labeled antibody was 1∶500. The virus strain of influenza H7N9 vaccine was used as antigen at a concentrations of 4.5lgCCID50/ml in solution with a pH of 6.5. Influenza-specific NI titers detected after immunization with vaccine were significantly higher than those before vaccination (P<0.001). In the 34 subjects receiving H7N9 vaccine, the seroconversion rate of NI antibody was 47% (≥40 in NI titer ), which was lower than that of HI antibody (P<0.05). Conclusions An ELLA with natural substrate for measurement of anti-influenza NI antibody was developed. It is simple and practical and might be used in the establishment of immune evaluation system for influenza vaccines and NI antibody. Key words: H7N9 influenza vaccine; Neuraminidase inhibition antibody; ELLA

Improving immunogenicity of influenza virus H7N9 recombinant hemagglutinin for vaccine development

Human infections of novel avian influenza A virus (H7N9) emerged in early 2013 and caused about 40% case-fatality through 2017. Therefore, development of influenza H7N9 vaccines is critical for pandemic preparedness. Currently, there are three means of production of commercial influenza vaccines: egg-based, mammalian cell-based, and insect cell-based platforms. The insect cell-based platform has the advantage of high speed in producing recombinant protein. In this study, we evaluate the stability and immunogenicity of two different influenza H7 HA expression constructs generated using the baculovirus system, including membrane-based full-length HA (mH7) and secreted ectodomain-based H7 (sH7). The mH7 construct could form an oligomer-rosette structure and had a high hemagglutinin (HA) titer 8192. In contrast to mH7, the sH7 construct could not form an oligomer-rosette structure and did not have HA titer before cross-linking with anti-His antibody. Thermal stability tests showed that the sH7 and mH7 constructs were unstable at 43 °C and 52 °C, respectively. In a mice immunization study, the mH7 construct but not the sH7 construct could induce robust HI and neutralizing antibody titers. In conclusion, further development of the mH7 vaccine candidate is desirable.

Immunological modulation effects of an acid Epimedium polysaccharide on immune response in chickens

The purpose of the present study is to investigate the immunological activities of EPS-1 in the non-specific immune response and specific immune response of chickens. In vitro, the results showed that EPS-1 could increase the proliferation and cytokine secretion (IL-2, IL-4, IFN-γ and TNF-α) of spleen lymphocytes, expression of key surface molecules (MHC II, CD11c, CD40 and CD86) and cytokine secretion (TNF-α and IL-10) of matured chBM-DCs, phagocytic rate of matured chBM-DCs, and enhance the maturation and stimulating capacity of chBM-DCs. In vivo, EPS-1 could also prompt the HI antibody titer, boost the peripheral lymphocyte proliferation, enhance the release of cytokine products in blood (IFN-γ, IL-4 and IL-2) and duodenum (IL-17 and sIgA) of chickens. These results indicated that EPS-1 may have the potential as a powerful immune adjuvant in the treatment of chicken diseases.

Efficacy of A/H1N1/2009 split inactivated influenza A vaccine (GC1115) in mice and ferrets.

To evaluate the efficacy of a non-adjuvant A/H1N1/2009 influenza A vaccine (GC1115), we demonstrated the immunogenicity and protective efficacy of GC1115 in mouse and ferret models. The immunogenicity of GC1115 was confirmed after intramuscular administration of 1.875, 3.75, 7.5, and 15 μg hemagglutinin antigen (HA) in mice and 7.5, 15, and 30 μg HA in ferrets at 3-week intervals. A single immunization with GC1115 at HA doses > 7.5 μg induced detectable seroconversion in most mice, and all mice given a second dose exhibited high antibody responses in a dose-dependent manner. The mice in the mock (PBS) and 1.875 μg HA immunized groups succumbed by 13 days following A/California/ 04/09 infection, while all mice in groups given more than 3.75 μg HA were protected from lethal challenge with the A/California/04/09 virus. In ferrets, although immunization with even a single dose of 15 or 30 μg of HA induced detectable HI antibodies, all ferrets given two doses of vaccine seroconverted and exhibited HI titers greater than 80 units. Following challenge with A/California/04/09, the mock (PBS) immunized ferrets showed influenza-like clinical symptoms, such as increased numbers of coughs, elevated body temperature, and body weight loss, for 7 days, while GC1115- immunized ferrets showed attenuated clinical symptoms only for short time period (3-4 days). Further, GC1115-immunized ferrets displayed significantly lower viral titers in the upper respiratory tract (nasal cavity) than the mock vaccinated group in a dose-dependent manner. Taken together, this study demonstrates the immunogenicity and protective efficacy of GC1115 as a non-adjuvanted vaccine.

Immunomodulatory Effect of Purified Exotoxins of &amp;lt;i&amp;gt;Staphylococcus aureus&amp;lt;/i&amp;gt; in Association with Bird Flu Virus Vaccine in Broilers

Immunization is the most effective method still used against infectious agents. Although not always, vaccines ineffectiveness is reported enormously against many of the pathogens throughout the world in poultry, particularly in case of killed or sub unit vaccine. The current project is, therefore, carried out as a preliminary study on broiler chickens to investigate the modulation of immune system against avian influenza virus in association with purified Staphylococcus aureus toxoid. After isolation of Gram positive cocci bacteria on mannitol salt agar from raw milk, yogurt and chicken meat were subsequently biochemically characterized by using rapid diagnostic kit. Pure culture of S. aureus was inoculated into digitally controlled bio-fermentor containing mannitol salt broth for production of toxins. Enormous production of bacteria was passed through sequence of filtration system based on 0.45 μm followed by 0.22 μm size. The centrifugation of the filtrate was made at 10,000 rpm for 60 minutes at 5℃ followed by 56,100 rpm for 20 minutes and clear supernatant containing Staphylococcus enterotoxin (SEs) was obtained. Bradford estimation of proteins further provided 305 μg/ml of SEs toxoid. Four types of oil adjuvant avian influenza type H9N2 virus vaccines (without toxoid, 91.5 μg/0.3ml, 22.8 μg/0.3ml and 11.43 μg/0.3ml) were injected into healthy AI H9N2 susceptible broilers and anti-H9N2 HI antibody titers were measured in terms of hemagglutination inhibition test. It was observed that on the 8th day, post vaccination cumulative mean anti AIH9 HI antibody titer of G-1, G-2, G-3, G-4 and G-5 was 3.13 ± 0.406, 5.13 ± 0.246, 3.96 ± 0.159, 3.25 ± 0.237 and 0.78 ± 0.467 respectively. It was found that all the vaccines induced protective titers 18 days’ post vaccination, but vaccine containing 91.5 μg/dose of SEs toxoid showed significantly higher (P , particularly in inactivated vaccines, could be the better choice for modulation of immediate and better immune response in future vaccines technologies.

Biological characteristics and immunological properties in Muscovy ducks of H5N6 virus-like particles composed of HA-TM/HA-TMH3 and M1

ABSTRACTHighly pathogenic avian influenza viruses (HPAIVs), including H5N6 strains, pose threats to the health of humans and poultry. Waterfowl play a crucial role as a reservoir of HPAIVs. Since current influenza vaccines induce poor antibody titres in waterfowl, there is an urgent need to develop an efficient vaccine against H5N6 infection. In this study, we constructed two H5N6 virus-like particles (VLPs) composed of matrix-1 (M1) and haemagglutinin of wildtype (HA-TM) or haemagglutinin with transmembrane domain replacement (HA-TMH3) (designated as H5N6 VLPs-TM and H5N6 VLPs-TMH3). Biological characteristics of the composed H5N6 VLPs were compared including localization, expression, contents of HA trimers, thermal stability, morphology and immunogenicity in Muscovy ducks. Our results indicate that the H5N6 VLPs-TMH3 contained more HA trimers and presented better thermal stability. Moreover, Muscovy ducks immunized with H5N6 VLPs-TMH3 produced higher titres of HI antibody and IFN-γ compared with those immunized with the same dose of H5N6 VLP-TM, thus providing a promising approach for the development of influenza virus vaccines for waterfowl.RESEARCH HIGHLIGHTSH5N6 VLPs-TMH3 had more HA trimers and resisted higher temperature than H5N6 VLPs-TMH5N6 VLPs-TMH3 induced higher titre of HI than H5N6 VLPs-TM in Muscovy ducks

Variations of immunoglobulin A in serum, tracheal, and intestinal tissues in chickens following inoculation of two strains of Newcastle disease vaccines

To elucidate secretory immunoglobulin A (IgA) response as a part of mucosal immunity, it is decided to compare the effectiveness of intraocular administration of Hitchner B1 and thermostable I-2 vaccines in broiler chickens challenged with viscerotropic velogenic Newcastle disease virus (vvNDV) (Herts33). For this purpose, 301-day-old chicks were randomly divided in to the four groups. Groups 1 and 2 were inoculated with I-2 and HB1 vaccines twice via intraocular route with 1-week intervals, and groups 3 and 4 were considered positive and negative controls and birds were challenged 2 weeks after the second inoculation. Protection rate in I-2 and HB1 vaccine groups was 100% and 97% respectively with no significant differences (P > 0.05). All vaccinated groups showed elevation in ND HI antibody titer after vaccination. There were no significant differences (P > 0.05) in ND HI antibody between two vaccinated groups. First levels of detectable total IgA in a serum sample were observed 3 dpv1. No significant differences (P > 0.05) were observed between two vaccinated groups in IgA antibody titer in sera. The vaccinated groups were evaluated by IHC for detection IgA in the trachea and intestine. There were some differences between the vaccinated groups but these differences were not significant. Experimental studies have shown that both vaccines induce antibody production in mucosal surface and circulatory system and thermostable I-2 vaccine could be successfully used in the broiler chicken as effective as HB1 vaccine, so I-2 vaccine could be a suitable heat resistance candidate to reduce mortality in the poultry industry faced to vvND.

Gene cloning, expression and immune adjuvant properties of the recombinant fusion peptide Tα1-BLP on avian influenza inactivate virus vaccine

Thymosin α1 (Tα1) and bursin-like peptide (BLP) are both immunopotentiators. In order to investigate adjuvant of thymosin α1-bursin-like peptide (Tα1-BLP), we cloned the gene of Tα1-BLP and provided evidence that the gene of Tα1-BLP in a recombinant prokaryotic expression plasmid was successfully expressed in E. coli BL21. To evaluate the immune adjuvant properties of Tα1-BLP, chickens were immunized with Tα1-BLP combined with H9N2 avian influenza whole-inactivated virus (WIV). The titers of HI antibody, antigen-specific antibodies, AIV-neutralizing antibodies, levels of Th1-type cytokines (IFN-γ) and Th2-type cytokines (IL-4) and lymphocyte proliferation responses were determined. What's more, the viral loads and pathologic changes of lung tissue were observed by virus challenge experiment and HE staining to evaluate the immune protection of chickens. We found that Tα1-BLP enhanced HI antibody and antigen-specific IgG antibodies titers, increased the level of AIV-neutralizing antibodies, induced the secretion of Th1- and Th2-type cytokines, and promoted the proliferation of T and B lymphocyte, Furthermore, virus challenge experiment and HE staining confirmed that Tα1-BLP contributed to inhibition replication of the virus from chicken lungs and protected the lungs from damage. Altogether, this study suggested that Tα1-BLP is a novel adjuvant suitable for H9N2 avian influenza vaccine.

Efficacy of Two Commercial Inactivated H5 Avian Influenza Vaccines Against Circulating HPAI Subtype H5N8 in Quails, 2018

To investigate cross-protective efficacy of commercial inactivated H5 avian influenza vaccines against recent HPAI H5N8 virus in quails. We evaluate the efficacy of two inactivated commercial H5 AI vaccine (imported H5N1 vaccine containing (Re-6 strain) and local H5N1 vaccine), using susceptible quails at one week age. The selection of these bird back to its a specific nature which characterized by presence of two types of avian influenza receptors giving a great chance for recombination of the different types of AIV emerging new mutant viruses can threat human health and poultry industry. Susceptible quails used for potency assay inoculated by one field dose and booster dose at 3 week post vaccination from each vaccine. Blood samples are collected weekly from all vaccinated groups and AI, HI antibodies are measured individuals of the collected sera by HI test using homologous H5N1 and heterologous H5N8 AI antigens containing 4 HA units. Vaccinated quails by one dose and booster dose of vaccine were challenged by 100 LD50 HPAI subtype H5N8 intranasally after 2, 4 and 8 weeks post vaccination, and 4 weeks post boostering, respectively. It was found HI antibody titer in sera of quails vaccinated by one or two doses of imported H5N1 AI vaccine containing RE-6 strain elicited higher immune response than local commercial vaccine when examined against homologous H5N1AI antigen, but two vaccines exhibited antibody titer not optimal against heterologous H5N8AI antigens. A challenge test with local H5N8 highly pathogenic influenza virus indicated unsatisfactory protection% for all groups of vaccinated quails.

Preparation and immunological evaluation of inactivated avian influenza virus vaccine encapsulated in chitosan nanoparticles

Efficacy maximization of inactivated avian influenza vaccine using safe adjuvants was investigated. Chitosan nanoparticles were prepared by ionic gelation method with average size of 150 nm and their Zeta potential was 11.5 mV. After encapsulation of avian influenza vaccine, the average size was 397 nm and Zeta potential was 4.29 mV. The highest HI antibody titer results were shown in chicken group vaccinated with inactivated avian influenza virus AIV-chitosan followed by the group vaccinated with inactivated AIV-chitosan nanoparticles then the group vaccinated with oil inactivated AIV vaccine, on using chicken antigen at 2 weeks post second vaccination. Upon using duck antigen, the highest HI antibody titers were shown in chicken group vaccinated with inactivated AIV oil emulsion vaccine followed by chicken group vaccinated with AIV-chitosan nanoparticles then the group vaccinated with AIV–chitosan. Chicken in the group vaccinated with AIV-chitosan nanoparticles induced the best results of lymphocyte proliferation assay. The results of phagocytic activity percentage and phagocytic index of AIV-chitosan nanoparticles and AIV–chitosan groups at 3 days post first vaccination were increased significantly in comparison with other groups, whereas at 14 days post first vaccination, group vaccinated with AIV-chitosan nanoparticles showed significant increase in phagocytic activity percentage and phagocytic index.

Recombinant influenza H7 hemagglutinin containing CFLLC minidomain in the transmembrane domain showed enhanced cross-protection in mice

Since February 2013, H7N9 influenza virus, causing human infections with high mortality in China, has been a potential pandemic threat. The H7N9 viruses are found to diverge into distinct genotypes as other influenza viruses; thus a vaccine that can provide sufficient cross-protection against different genotypes of H7N9 viruses is urgently needed. Our previous studies demonstrated that the HA-based structural design approach by introducing a CFLLC minidomain into transmembrane domain (TM) of H1, H5 or H9 hemagglutinin (HA) proteins by replacing with H3 subtype HA TM could enhance their cross-protection. In this study, we used Sf9 insect cell expression system to express recombinant H7 HA proteins H7-53WT, in which HA gene was derived from H7N9-53 strain, and H7-53TM containing CFLLC minidomian by replacing its TM domain with H3 HA TM. We investigated whether introduction of CFLLC minidomain into H7 HA (H7-53TM) could increase its cross-reactivity and cross-protection against different genotypes of H7N9 viruses. The results showed that the H7-53TM either with or without squalene adjuvant induced increased HI antibodies, serum IgG antibodies, and IFN-γ production to a panel of 7 H7N9 viruses in mice. Vaccinated animals with H7-53TM alone showed complete protection against challenge with heterologous H7N9-MCX strain, while H7-53WT alone showed incomplete protection (80%). Furthermore, mice vaccinated with H7-53TM HA showed less body weight loss and less pulmonary lesions and inflammation after challenge with homologous or heterologous H7N9 viruses, comparing to H7-53WT. In summary, this study presents a better subunit vaccine candidate (H7-53TM) against potential H7N9 pandemic.

Longevity of protective immune responses induced by a split influenza A (H7N9) vaccine mixed with MF59 adjuvant in BALB/c mice.

The influenza virus is a serious threat to public health worldwide. A novel avian influenza A (H7N9) virus with a mortality rate of approximately 30% has been identified as an unusually dangerous virus for humans by the World Health Organization. Pathogenic H7N9 continue to represent a public health concern, and several candidate vaccines are currently in development. We generated candidate H7N9 vaccine strains using reverse genetics, consisting of hemagglutinin and neuraminidase genes derived from a human H7N9 virus and the remaining genes from the PR8 (A/PuertoRico/8/34 (H1N1)) virus. This H7N9 vaccine exhibited superior efficacy when combined with MF59 compared to other adjuvants. Immunized BALB/c mice were followed to determine the duration of the protective immune response. Antibody levels decreased to between one-half and one-eighth of the peak values four months after the final dose of the vaccine. Previously vaccinated mice received an A/Zhejiang/DTID-ZJU01/2013 H7N9 challenge six months post-vaccination, and all remained protected. We also verified that MF59 enhanced the HI, MN, and IgG antibody titers to influenza antigens. The humoral immune response and Th2 cytokine production following influenza challenge was potently induced in the animals that received the split vaccine. Therefore, the split H7N9 influenza vaccine with the MF59 adjuvant could effectively induce antibody production and protect mice from H7N9 virus challenge even after six months.

Vaccine efficacy against Indonesian Highly Pathogenic Avian Influenza H5N1: systematic review and meta-analysis.

Indonesia has implemented multiple strategies to control Highly Pathogenic Avian Influenza H5N1 (HPAI/H5N1), including the licensure and use of multiple vaccine formulations. The continuous drift of Indonesian HPAI/H5N1 viruses and emergence of a new clade in 2012 that became dominant in 2016, demands the assessment of commercial vaccine formulations against Indonesian field viruses. Seven databases were explored to identify relevant literature reporting performance of commercial vaccines against Indonesian HPAI/H5N1 viruses. After methodological assessment, data were collated and analyzed to report immunogenicity and vaccine efficacy (VE) to prevent respiratory and cloacal viral shedding 2-day post challenge, and death at the end of the follow-up period. Meta-analyses were performed to assess VE consistency of alternative formulations and to explore sources of heterogeneity in VE. In total, 65 studies and 46 vaccine formulations from 13 articles were grouped per OIE's VE protocols (group 1) and variations of it (groups 2,3,4). We found that concurrence of vaccine-seed and challenge-viruses in a clade designation might be a better proxy of VE than current estimates based on vaccine-homologous HI antibody titers, particularly against current fourth order clade viruses (groups 1&2). Prime-boosting was efficacious across different chicken breeds (group 3), and early vaccination may increase the risk of death (group 4). One Indonesian vaccine was tested against the new dominant clade, conferring consistent protection in chickens but not in ducks. Meta-analyses revealed high inconsistency (I2≥75%) and inefficacy of LPAI formulations against current field viruses, while potential sources of inconsistent VE were formulation of seed-homologous vaccines and the species vaccinated. We conclude that the VE of commercial vaccines in Indonesia changes as Indonesian HPAI/H5N1 evolve into new clades, which should warrant continuous matching between vaccine-seeds and emerging HPAI/H5N1. Furthermore, given the characteristics of the new Indonesian dominant HPAI/H5N1 clade, further studies to confirm VE across species are warranted.

Analysis of immunostimulatory activity of polysaccharide extracted from Yu-Ping-Feng in vitro and in vivo

As a traditional Chinese multiherbal formula, Yu-Ping-Feng (YPF) is frequently used to treat cold, flu and inflammation-associated diseases. We aimed to evaluate the immunostimulatory effects of polysaccharide isolated from YPF (YPF-PS) in vitro and in vivo. In in vitro experiment, macrophage cell proliferation, phagocytosis rate, cytokine and costimulatory molecule release, T lymphocyte proliferation, cell cycle distribution, CD4+ and CD8+ T cell percentages were determined. To investigate the in vivo effects of YPF-PS treatment, different doses YPF-PS were administered to chicken vaccinated against Newcastle disease. The immune organ index, lymphocyte proliferation, antibody titer, cell cycle distribution, and the cell percentage of CD4+ and CD8+ were assessed. In vitro results indicated that YPF-PS at 15.62μgmL−1 could increase the LPS-induced macrophage cell proliferation and phagocytosis rate significantly. The levels of cytokine (nitric oxide, tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6, and interferon beta) and costimulatory molecules (CD80 and CD86) were also considerably enhanced. Moreover, YPF-PS could significantly enhance T lymphocyte proliferation individually or synergistically with phytohemagglutinin. It promoted lymphocyte entry into S and G2/M phases and increased the percentages of CD4+ and CD8+ T cells effectively. In addition, in vivo experiments showed that YPF-PS could enhance serum HI antibody titer. The results about T lymphocyte proliferation, cell cycle distribution, CD4+ and CD8+ cell percentages in chickens were also confirmed. YPF-PS has efficacious immunomodulatory properties and could be used as a new potential immune stimulator for food and medical purposes.

Respons Imun Ayam Petelur Pascavaksinasi Newcastle Disease dan Egg Drop Syndrome

Some viral diseases in poultry could lead to huge losses to the farmers. Newcastle Disease (ND) and Egg Drop Syndrome (EDS) are a group of infectious viral disease that can cause the decreasein egg production. Newcastle Disease is caused by Avian paramyxovirus type 1 (PMV-1) Paramyxoviridae family. The causative agent of EDS is Duck adenovirus-I Adenoviridae family. Both of these diseases affect the economic losses to the poultry. The main action to prevent hens from ND and EDS virus diseases is vaccination. The success ofvaccination can be tested by serology. ND and EDS virus characteristically agglutinate hen’s erythrocyte they have Hemagglutine protein on virus envelope so can be tested by hemagglutination. The study was conducted ona commercial poultry farm in order to determine the success of vaccination against ND and EDS. The hens were vaccinated by Newcastle Disease-Infectious Bronchitis- Egg Drop Syndrome (ND-IB-EDS) inactivated vaccines.Serological test was conducted in pre and post vaccination by using microtiter hemagglutination test. The antibody titre is expressed in units of HI log2. The results of the study, the mean antibody titer against ND pre vaccinationwas 4,53 ± 1,356 HI log2 and antibody titre in 2nd, 3rd and 4th week were 8,67 ± 0,617 HI log2, 7,73 ± 1,335 HI log2 and 5,20 ± 0,862 HI log2 post vaccination. Antibody titre against EDS pre vaccination was 0 ± 0,000 HI log2 and antibody titre post vaccination in 2nd, 3rd and 4th week were 7 ± 1,363 HI log2, 7,27 ± 1,438 HI log2 and 7,6 ± 1,056 HI log2. It showed that ND-IB-EDS inactivated vaccines is serological protective for ND and EDS titres.