Strategies of newcastle disease vaccination for commercial ostrich farms in Japan

Strategies of Newcastle disease (ND) vaccination were demonstrated in a commercial ostrich farm in Japan. Three of 13 seven-month-old ostriches kept in a pen were vaccinated with a live ND vaccine by eye dropping for the 1st and 2nd vaccinations and spraying for the 3rd to 5th vaccinations. Antibodies against ND virus (NDV) were detected in all of the unvaccinated ostriches by virus neutralization test. At 2.5 months post final vaccination, 2 ostriches introduced into the pen raised antibodies against NDV. These data indicate that NDV may be transmitted from vaccinated to unvaccinated ostriches in the flock and that the virus may be sustained for a certain period in the flock. These data may be helpful for ND vaccination management in ostrich farms.     

A controlled vaccination trial for Newcastle disease under village conditions

All the poultry in each of four distinct Moroccan villages were vaccinated against Newcastle disease using Hitchner B1 and inactivated vaccines. Poultry in a fifth village were monitored as controls. Mortality in the poultry was followed for 20 weeks after the first vaccination and blood samples were taken every 4 weeks from chickens for estimation of antibodies against Newcastle disease virus. Sixty-three percent of the chicken population and 60% of the turkey population in the control village died during the 20 weeks of observation. Necropsied birds showed lesions consistent with Newcastle disease. Mortality did not exceed 22% in the vaccinated villages.     

Situation of serum antibodies against Newcastle disease virus in slaughter-age ostriches after vaccination campaign in Japan

A total of 516 slaughter-age ostrich sera were collected in Japan during 2006-2009. Sixty-one of five hundred and sixteen were positive by virus neutralization (VN) test and the titer of most positive samples was low level. Within the 61 positive sera, 35 sera were collected from unvaccinated ostriches. This result implies that these ostriches might have been infected naturally with low-virulent Newcastle disease virus (NDV). Within the 455 negative samples, 125 samples were from vaccinated ostriches. Since ostrich farmers use live attenuated vaccines, it is reasonable that the titer decreased to below detection level by 1 or 1.5 year-old. The above data indicate that NDV has infiltrated into ostrich farms in Japan, and that the efficacy of ostrich ND vaccination is often time-limited.     

武汉市新洲区2021年高致病性禽流感和新城疫免疫抗体监测数据浅析

高致病性禽流感（highly pathogenic avian influenza, HPAI）和新城疫（newcastle disease, ND）等烈性传染病对养禽业危害严重,是养禽业需重点防控的疾病,其中HPAI是国家规定的强制免疫疫病。武汉市新洲区为家禽养殖大区,有规模禽场350余家,养殖规模近1140万只。为了解2021年度武汉市新洲区规模养殖场高致病性禽流感和新城疫免疫抗体合格率,武汉市新洲区农业技术推广服务中心连续12个月对辖区内规模鸡场进行蛋样抽检,运用血凝和血凝抑制试验,分别检测了高致病性禽流感H5亚型、H7亚型和新城疫的免疫抗体。结果显示,高致病性禽流感H5亚型、H7亚型和新城疫的整体免疫抗体合格率分别为94.1%、96.4%和88.9%,均达到了农业农村部规定的免疫抗体合格率不低于70.0%的标准。     

Consequence of Cryptosporidiosis on the immune response of vaccinated broiler chickens against Newcastle disease and/or avian influenza

The consequence of cryptosporidiosis on the immune response of vaccinated chickens against Newcastle disease and/or avian influenza was studied by using 240, 1 day old, male, white Hy-Line chicks and divided into 8 groups and subgroups. Each group or subgroup was consisting of 30 chicks (15?×?2 replicates). The first and second groups were kept as unvaccinated control, G1uninfected and G2 infected. G3, G4 and G5 contained 2 subgroups A&B (G3A, G3B, G4A, G4B, G5A and G5B). Chicks of subgroup A were vaccinated only while chicks of subgroup B were infected and vaccinated. These chicks were orally inoculated with 5?×?10⁵ oocysts of Cryptosporidium baileyi (C. baileyi) at 2 days of age. Chickens were vaccinated intraocular with live Newcastle disease (ND) vaccine (Hitchner on day 7th and LaSota on day 17th of chicken life) (G3) or vaccinated by subcutaneous route with Volvac®- H5N2- AI vaccine on day 10 of chicken life (G4). Last group (G5) was infected similarly and vaccinated with ND and AI vaccines with the same day, dose and route of vaccination for each one. Random blood samples were collected for 3 weeks post-vaccination for investigation of humoral immune response against Newcastle and/or avian influenza vaccines by the haemagglutination inhibition (HI) test. The results showed that H5N2 vaccine at day 10 of chicken life is effective in chickens indicated by the geometric mean of HI titer against AI virus. The findings of this study showed that the infection with Cryptosporidia in the broiler chicken has a depressive effect on the immune status of the birds vaccinated against ND and/or AI vaccination. Moreover, the obtained protection rates against challenge with virulent ND virus observed to be parallel to the results of HI- test. Also, by using 2 different antigens (one commercial and field prepared antigen) to avian influenza virus, lower Geometric mean (GM) HI titer were appeared in infected and vaccinated group than vaccinated group only. A study of the relative lymphoid organs weight such as bursa of Fabricius from the experimental chicks indicated that those organs were comparable between the groups infected-vaccinated and vaccinated only. Non significant variations in final live weight between uninfected control and infected groups were indicated. Also, H5N2-AI vaccination at 10 days old did not affect the final live weight. ND and/or AI Vaccination could not be a substitute to application of good hygienic measures and fecal examination of the birds especially for protozoal diseases such as cryptosporidiosis. It could be concluded that cryptosporidiosis could be one cause of ND and/or AI vaccination failure in poultry farms.     

Development of a virosome vaccine for Newcastle disease virus

In an effort to protect chickens against Newcastle disease (ND), a nonreplicating virosome vaccine was produced by solubilization of Newcastle disease virus (NDV) with Triton X-100 followed by detergent removal with SM2 Bio-Beads. Biochemical analysis indicated that the NDV virosomes had similar characteristics as the parent virus and contained both the fusion and hemagglutinin-neuraminidase proteins. To target the respiratory tract, specific-pathogen-free chickens were immunized intranasally and intratracheally with the NDV virosome vaccine. This vaccine was compared with a standard NDV (LaSota) live-virus vaccine for commercial poultry. Seroconversion (> or = four fold increase in hemagglutination inhibition [HI] antibody titers) was achieved in all birds vaccinated with the virosome vaccine. Upon lethal challenge with a velogenic NDV strain (Texas GB), all birds receiving either vaccination method were protected against death. Antibody levels against NDV, as determined by enzyme-linked immunosorbent assay and HI titer, were comparable with either vaccine and increased after virus challenge. These results demonstrate the potential of virosomes as an effective tool for ND vaccination.     

Immunisation of fancy chickens against Newcastle disease]

The German Regulation on Fowl plague which is in force since 1994 laid down that any chicken of all races and all hybrids must be vaccinated against Newcastle disease (ND) in a mode that an adequate immunity is achieved. Onset, duration, and resistance to challenge of immunity induced by vaccination is well documented in the scientific literature for hybrid chicken of the layer and meat types. These data prove also innocuity and efficacy of the registered vaccines. In contrast, only a few and incomplete data exist on the development of ND directed immunity in fancy chickens. The present study describes vaccinations of chickens of 14 different hobby breeds with live LaSota vaccine (conjunctival application of 10(6) embryo-infective dose50 per bird) and with an inactivated oil-emulsion vaccine (intramuscular application of 0.5 ml per bird) and subsequent intramuscular challenge infections using the highly virulent NDV strain Herts 33/66. Chickens of all 14 breeds tolerated the application of both vaccines. All fancy chickens reacted with the production of serum antibodies which were measured in the haemagglutination inhibition (HI) and virus neutralisation (VN) tests. According to the scientific literature, maximal antibody levels are reached in hybrid chickens between day 10 and 20 post vaccination. In contrast, in fancy chickens the antibody maxima are delayed to the seventh to eighth week post vaccination. All fancy chickens vaccinated either once with live LaSota virus or with live and inactivated vaccines resisted challenge with the highly virulent Herts 33/66 strain of NDV and did not develop any signs of disease. There are indications for gradual differences in susceptibility of different breeds of fancy chickens. The levels of non-specific neutralisation as measured in the virus neutralisation test differ between breed. Also, the viral content in tissues obtained from non-vaccinated but challenged birds differ markedly. It is concluded from the results of this study that fancy chickens can also successfully protected against Newcastle disease by using live and inactivated vaccines which are licensed for hybrid chickens. However, the optimal time for the detection of maximal antibody levels in fancy chickens is reached seven to eight weeks post vaccination.     

Determination of the distribution of lentogenic vaccine and virulent Newcastle disease virus antigen in the oviduct of SPF and commercial hen using immunohistochemistry

The control of Newcastle disease (ND) in South Africa has proved difficult since 2002 following the introduction of lineage 5d/VIId Newcastle disease virus (NDV) strain ("goose paramyxovirus" - GPMV) to which commercially available ND vaccines appeared less effective. Most of the ND infections, even in fully vaccinated hens were characterized consistently by a drop in egg production. In this study, commercial and SPF hens-in-lay were vaccinated with La Sota vaccine and challenged with a GPMV isolate. Immunohistochemical labeling was used to determine the distribution of viral antigen in the oviduct of the hens. Following reports that cloacal vaccination offered better protection against egg production losses than the oro-nasal route, the efficacy of cloacal and ocular routes of vaccination against challenge were compared. Results showed that La Sota vaccine offered birds 100% protection against the virulent ND (GPMV) virus challenge from clinical disease and death, but not against infection and replication of the GPMV, as birds showed varying degrees of macropathology. Histopathology of the oviduct of infected birds revealed multifocal lymphocytic inflammation in the interstitium as well as mild glandular ectasia and mild edema. Finely granular NDV-specific immunolabeling was demonstrated in the cytoplasm of epithelial cells and mononuclear (lymphohistiocytic) cells in the interstitium of the oviduct. Both vaccine and virulent GPMV showed greatest tropism for the uterus (versus the magnum and isthmus). There was no clear difference in the protection of the oviduct and in the distribution of oviductal GPMV antigens between the two routes of vaccination.     

Serological and virological studies of Newcastle disease and avian influenza in slaughter-age ostriches (Struthio camelus) in Japan

Serum samples from 191 ostriches (Struthio camelus) in Japan were tested for antibodies to Newcastle disease virus (NDV) and avian influenza virus (AIV). Twenty-two (12%) contained NDV-specific neutralizing antibodies by a virus-neutralization (VN) test without vaccination. Antibodies to AIV were not detected in the any sera by an agar gel precipitation test. Seven serum samples that had vaccinated with live NDV by eye drop were all positive by the VN test at 1 month post vaccination. A haemagglutination inhibition (HI) test for NDV seemed not to be suitable for ostriches because of non-specific agglutination of chicken red blood cells. No haemagglutinating viruses were isolated. This is the first report on detection of antibodies against NDV in ostriches in Japan.     

Improvements to the hemagglutination inhibition test for serological assessment of recombinant fowlpox-H5-avian-influenza vaccination in chickens and its use along with an agar gel immunodiffusion test for differentiating infected from noninfected vaccinated animals

In general, avian influenza (AI) vaccines protect chickens from morbidity and mortality and reduce, but do not completely prevent, replication of wild AI viruses in the respiratory and intestinal tracts of vaccinated chickens. Therefore, surveillance programs based on serological testing must be developed to differentiate vaccinated flocks infected with wild strains of AI virus from noninfected vaccinated flocks in order to evaluate the success of vaccination in a control program and allow continuation of national and international commerce of poultry and poultry products. In this study, chickens were immunized with a commercial recombinant fowlpox virus vaccine containing an H5 hemagglutinin gene from A/turkey/Ireland/83 (H5N8) avian influenza (AI) virus (rFP-H5) and evaluated for correlation of immunological response by hemagglutination inhibition (HI) or agar gel immunodiffusion (AGID) tests and determination of protection following challenge with a high pathogenicity AI (HPAI) virus. In two different trials, chickens immunized with the rFP-H5 vaccine did not develop AGID antibodies because the vaccine lacks AI nucleoprotein and matrix genes, but 0%-100% had HI antibodies, depending on the AI virus strain used in the HI test, the HI antigen inactivation procedure, and whether the birds had been preimmunized against fowlpox virus. The most consistent and highest HI titers were observed when using A/turkey/Ireland/83 (H5N8) HPAI virus strain as the beta-propiolactone (BPL)-inactivated HI test antigen, which matched the hemagglutinin gene insert in the rFP-H5 vaccine. In addition, higher HI titers were observed if ether or a combination of ether and BPL-inactivated virus was used in place of the BPL-inactivated virus. The rFP-H5 vaccinated chickens survived HPAI challenge and antibodies were detected by both AGID and HI tests. In conclusion, we demonstrated that the rFP-H5 vaccine allowed easy serological differentiation of infected from noninfected birds in vaccinated populations of chickens when using standard AGID and HI tests.     

Immunogenicity and protective efficacy of virosome based vaccines against Newcastle disease

Virosome based vaccines against Newcastle disease (ND) were prepared and evaluated for their immunogenicity and protective efficacy in chickens. Envelop of Newcastle disease virus (NDV) was solubilised with Triton X-100 to yield virosomes which were later on encapsulated in poly-lactide-co-glycolide (PLG) microspheres. The birds were immunized intranasally with virosomes or PLG microspheres encapsulated virosomes, and efficacy of these preparations was compared with commercial LaSota vaccine. The preparations protected the chickens against virulent virus challenge infection, however the microencapsulated virosome vaccine gave slightly lesser degree of protection than non encapsulated counterpart. The humoral and cell mediated immune response generated as well as the protection afforded by virosome preparations were found to be comparable with LaSota vaccine. The results substantiate the potential of virosome based vaccines to provide high level of immunity and protection against Newcastle disease.     

新城疫的合理免疫及常见疫苗使用误区

新城疫是由新城疫病毒引起的危害多种家禽特别是陆生禽类的最主要的传染病之一,疫苗免疫接种是目前国内预防该病的主要防疫手段。试验研究及临床实践结果表明,使用与流行株基因型匹配的疫苗株,并采用新城疫活疫苗配合灭活疫苗的免疫方式,可起到体液免疫及细胞免疫的双重作用,其中黏膜免疫在预防新城疫中也发挥重要作用。笔者在长期基层养殖技术服务中发现,很多养殖场在新城疫疫苗的使用方案、方法及免疫程序等方面存在一些误区,严重干扰了疫苗发挥作用,从而造成临床新城疫的发病。     

Epidemiology,control, and prevention of Newcastle disease in endemic regions: Latin America

Tropical Animal Health and Production - Newcastle disease (ND) infects wild birds and poultry species worldwide, severely impacting the economics of the poultry industry. ND is especially...     

Investigations on the Influence of Helminth Parasites on Vaccination of Chickens against Newcastle Disease Virus under Village Conditions

Prevalence studies have shown that almost 100% of free-range chickens are infected with a wide range of parasites. The infections are mostly subclinical in nature, resulting in production losses and occasionally mortality. Newcastle disease (ND), on the other hand, results in high mortality rates during epidemics. ND is a limiting factor for increasing poultry production in many tropical countries, where frequent reports indicate vaccination failures. The aim of our study was to investigate the influence of helminths on the antibody response after vaccination against Newcastle disease of free-range chickens naturally infected with parasites. Sixty chickens were divided into six groups, of which three were vaccinated against ND with a live De Soto vaccine, while the other three remained non-vaccinated. One group within the vaccinated groups and the one within the non-vaccinated group was kept naturally infected with helminth parasites, while the other two groups in each set were dewormed with fenbendazole and niclosamide, and one of each of these groups was subsequently infected with Ascaridia galli. After vaccination, all the groups were followed for 5 weeks and their antibody titres were determined weekly using a HI test. All the birds were finally challenged 4 weeks after vaccination with a virulent velogenic ND virus obtained from a field outbreak. All the vaccinated chickens seroconverted and had high antibody levels after 3 weeks, but these dropped to low levels at 4 weeks after vaccination. After challenge, the antibody titres rose in the dewormed groups but not in the parasite-infected groups. After 5 weeks, all the parasite-infected animals had significantly lower antibody titres than the dewormed animals. All the vaccinated chickens survived the challenge infection, emphasizing the importance of the cellular immune response. Further studies are needed to examine the effects of the parasitic infection on protection against ND over a longer period.     

LaSota vaccination may not protect against the lesions of velogenic newcastle disease in chickens

Two groups of six weeks old cockerels comprising 40 immunized and 40 non-immunized birds were inoculated intramuscularly with VGF-1, which is a local Nigerian strain of velogenic Newcastle disease virus (VNDV). Immunized birds did not show any clinical signs except significant loss (p < 0.05) in body weight on days 5 and 20 post inoculation (PI). But the non-immunized birds showed clinical signs of disease characterized by anorexia and drowsiness from day 2 PI. These were followed on day 3 PI by depression, diarrhoea, opisthotonus, weight loss (p < 0.05) and high mortalities (96.9%). Both the immunized and non-immunized groups showed severe atrophy of the bursa, spleen and thymus. Histopathological section of these lymphoid organs showed necrosis and depletion of lymphocytes. Both the gross and microscopic lesions were more severe in the non-immunized birds. Marked ballooning degeneration was observed in the bursal follicles of the non-immunized birds. This lesion has not been described earlier for any other disease and could be diagnostic for VND. Our results also showed that VND can cause marked atrophy of the lymphoid organs, which may lead to immunosupression without the characteristic signs of Newcastle disease (ND) in vaccinated chickens. This no doubt emphasizes the limitation of vaccination as a biosecurity measure in poultry industry. Ezema, W.S., J.O.A. Okoye and Nwanta, J.A., 2008. LaSota vaccination may not protect against the lesions of velogenic Newcastle disease in chickens. Tropical Animal Health and Production     

Newcastle disease vaccination: A comparison of vaccines and routes of administration in Pakistan

Twelve-day-old chickens were vaccinated once with different Newcastle disease (ND) vaccines ( F, La Sota and Mukteswar) by two different routes (intraocular and drinking water). Chickens from a seventh group were uninoculated controls. At weekly intervals for 7 weeks after vaccination, 20 chickens from each vaccinated group and 20 chickens from the control group were examined for the production of haemagglutination-inhibition (HI) antibodies and for protection as assessed after challenge with velogenic, viscerotropic ND virus.

La Sota ND vaccine used intraocularly ranked the best and Mukteswar vaccine by the drinking water route the worst for their HI antibody titres prior to challenge. Differences between the treatments in protection were examined. For all three vaccines intraocular vaccine produced higher protection than drinking water vaccine. An inverse relationship between prechallenge and postchallenge HI titres was also recorded.     

Antibody responses to La Sota strain vaccines of Newcastle disease virus in ostriches (Struthio camelus) as detected by enzyme-link ed immunosorbent assay

Because of the fact that South Africa is a Newcastle disease virus (NDV)-endemic country, major concerns exist that the export of ostrich meat could transmit velogenic strains of this disease. The ability to transmit the virus could be reduced by effective vaccination of South African ostriches. In this study, two vaccination trials were conducted to assess serum antibody production in response to vaccination with La Sota strain NDV vaccines. To this end, a commercially available chicken anti-NDV enzyme-linked immunosorbent assay (ELISA) was modified for the detection of anti-NDV antibodies in ostrich serum. The results obtained with this ELISA were verified by comparison with an indirect ELISA. In the first trial, ostriches were immunized subcutaneously four times with different volumes of an inactivated vaccine and their immune response was determined from 2.5 mo up to the ideal slaughter age of 14 mo. Results indicated that ostriches responded in a dose-dependent manner and gave support for the vaccination schedule currently recommended to South African farmers. In a second trial, immunization by eyedrop with a live La Sota vaccine of 5-wk-old ostriches did not elicit a humoral immune response. The results indicate that it is highly unlikely that ostriches that have been vaccinated according to the recommended vaccination schedule can transmit the virus.     

Protection of laying hens against infectious bronchitis with inactivated emulsion vaccines

Commercially-reared laying chickens were challenged at 31 weeks of age with a virulent infectious bronchitis (IB) virus. They showed a sharp drop in egg production, despite having been vaccinated at four and eight weeks old with live attenuated IB vaccines to a recommended schedule. In contrast, similar birds that had been further immunised at point-of-lay with inactivated oil emulsion IB vaccine, or with a combined IB/Newcastle disease (ND) emulsion vaccine, showed no detectable fall in egg production after the same challenge. Unvaccinated susceptible specific pathogen-free birds challenged at the same time stopped laying almost completely. In the birds revaccinated with emulsion vaccine, measurement of haemagglutination inhibition antibody levels to IB showed their geometric mean titres to be raised from less than 5 log2 at the time of vaccination to over 10 log2 four weeks later. Their antibody levels did not rise further followining the IB challenge whereas in the birds that had not been revaccinated antibody rises to nearly 10 log2 were detected after the same challenge. For pullets vaccinated earlier with live IB vaccine, revaccination with inactivated IB or IB/ND oil emulsion vaccine at point-of-lay provides a safe and effective way of protecting their egg production against IB infection.     

Adequacy of commercial lentogenic vaccines against Canadian strains of viscerotropic Newcastle disease virus.

Three field strains of Newcastle Disease virus, designated S20, S21 and S23, isolated from chickens or turkeys in Ontario during the 1971-72 epizootic, were characterized as velogenic viscerotropic viruses. No significant antigenic differences were demonstrated among B1, LaSota and a field strain (S23) of velogenic vescerotropic virus by haemagglutination inhibition or protection tests. Primary water vaccination of chicks with commercial B1 and LaSota vaccines at five weeks of age and aerosol revaccination with the same strains four weeks later resulted in protection that lasted 16 weeks after revaccination against experimental challenge with strain S23. The differences in haemagglutination inhibition titres noted when the homologous or the heterologous viruses were used as haemagglutinating antigen were not statistically significant. The rates of decay of virus neutralizing and haemagglutination inhibition antibodies in vaccinated birds showed a divergence indicating the possible duality of antibodies measured in serum neutralization and haemagglutination inhibition tests.     

Protective efficacy of commercial inactivated Newcastle disease virus vaccines in chickens against a recent Korean epizootic strain

Despite the intensive vaccination policy that has been put in place to control Newcastle disease virus (NDV), the recent emergence of NDV genotype VII strains in Korea has led to significant economic losses in the poultry industry. We assessed the ability of inactivated, oil-emulsion vaccines derived from La Sota or Ulster 2C NDV strains to protect chickens from challenge with Kr-005/00, which is a recently isolated Korean epizootic genotype VII strain. Six-week-old SPF chickens were vaccinated once and challenged three weeks later via the eye drop/intranasal route. All vaccinated birds were fully protected from disease, regardless of the vaccine strains used. All vaccinated and challenged groups showed significant sero-conversion 14 days after challenge. However, some vaccinated birds, despite being protected from disease, shed the challenge virus from their oro-pharynx and cloaca, albeit at significantly lower titers than the unvaccinated challenged control birds. The virological, serological, and epidemiological significance of our observations with regard to NDV disease eradication is discussed.