Development of a bovine ephemeral fever vaccine containing a new adjuvant
Yen-Lin Lee
Abstract
Bovine ephemeral fever (BEF) is an acute febrile illness affecting cattle and water buffaloes, caused by an arthropod-borne rhabdovirus. BEF has become an endemic and persistent infection disease in Taiwan affecting cattle. In addition to causing the the clinical symptoms such as high fever, respiratory syndrome and joint pain, this disease causes serious economic damage to the dairy industry, due to the potential reduction in milk production. Although the conventional aluminum phosphate (Al-gel) vaccine is safe, the high serum neutralizing (SN) antibody titer does not persist long enough to provide effective protection for cattle herds. To improve this, the development of the BEF vaccine containing a new adjuvant began in 2015. Animal trials were conducted on mice, rabbits, and cattle in succession and field trials started on two farms in 2018. Vaccine efficacy tests resulted in conferred immunity for one year after the 3rd immunization. The titers of SN antibodies remained high and had a long maintenance period. The vaccine was safe for both calves and pregnant cattle causing no adverse effects. Vaccine stability tests established that new vaccines from three different batches did not change in texture or color, and remained sterile after 21 months in storage. Safety tests conducted with rabbits and calves, demonstrated no adverse effects . Furthermore, efficacy test results demonstrated that the ability of the vaccine to elicit SN antibodies after long-term storage was almost the same as at the time of production, and that the results were very similar among the three batches. Calves exhibited viremia two days after challenges using the blood of infected cattle and viral nucleic acids were detected in calf blood for more than ten subsequent days. Meanwhile, calf body temperatures and respiratory rates also increased. In regard to the calves that were vaccinated prior to the challenge, no viremia or any other clinical signs were observed. In summary, this BEF vaccine displays an excellent ability to elicit a strong and enduring SN antibody response without significant safety concerns. The animal pharmaceutical license, with the change in adjuvant added to the BEF vaccine, was approved in 2019, and the current BEF vaccine manufactured by AHRI now contains this new adjuvant. This developmental result will hopefully provide a high efficacy vaccine to Taiwanese farmers by conferring increased immunological protection against BEF for cattle herds in Taiwan.
Manufacture of Freeze-dried Hog Cholera Lapinized
Live Vaccine
Chyi-Sing, Hwang
Abstract
Hog cholera, also known as classical swine fever (CSF), is caused by the Classical Swine Fever Virus (CSFV), and it is a highly contagious and lethal disease affecting swine. Clinical outcomes of CSFV infection can vary with different virus strains, from the acute form which can result in mortality, to strains resulting in mild, chronic or even inconspicuous symptoms. CSFV is a RNA virus belonging to the genus Pestivirus in the family Flaviviridae, which commonly induces fever, diarrhea and internal organ hemorrhage in infected hosts. AHRI produced 1,673,320 doses of the hog cholera lapinized vaccine in 2019, and an average of 522 doses were obtained per rabbit. As a result of animal welfare concerns, the hog cholera lapinized live vaccine will no longer be produced at AHRI starting in 2022.
The African Swine Fever diagnosis and monitoring program at the National Institute of Veterinary Research, Vietnam
Yu-Liang Huang, Ming-Chung Deng
Abstract
Since the August 2018 outbreak of African Swine Fever (ASF) in China, the disease has spread to South Asia and North Asia and became the most important disease affecting swine in the region. An important cornerstone for ASF disease prevention and control is based on rapid diagnostic test results. Therefore, ASF diagnostic methods were developed at the Animal Health Research Institute (AHRI) according to the OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals, and was implemented for the successful detection of ASFV nucleic acids from illegal meat production operations and floating pig carcasses. However, ASFV was not detected in these ASFV-positive samples due to insufficient viral nucleic acid extraction. In order to improve ASFV detection methods, researchers from AHRI examined the methods used at the National Institute of Veterinary Research (NIVR) in Hanoi, Vietnam from December 24-30, 2019, under the memorandum of understanding for the cooperation in ASF diagnosis and monitoring between AHRI and NIVR. The methods developed at AHRI for ASFV nucleic acid isolation and molecular detection were found to successfully detect ASFV in ASFV-positive field samples. Thus, this ASFV diagnostic method can meet the needs for clinical examination and monitoring in swine populations.
Reports on the ‘18th Meeting of the Asia Regional Advisory Group on Aquatic Animal Health’ and the ’1st Meeting of the ad hoc Steering Committee of the Regional Collaboration Framework on Aquatic Animal Health in Asia and the Pacific’ in Bangkok, Thailand
I-Wen Chen
Abstract
Aquaculture is the fastest-growing food-producing sector in the world and the Asia-Pacific region has dominated global aquaculture production, both in quantity and value. In order to stay current with aquatic animal health research, Dr. Chen I-Wen was dispatched to the ’18th Meeting of the Asia Regional Advisory Group on Aquatic Animal Health’ held by the Network of Aquaculture Centres in Asia-Pacific (NACA ) and the 1st Meeting of the ad hoc Steering Committee of the Regional Collaboration Framework on Aquatic Animal Health in Asia and the Pacific’ held by the OIE in Bangkok, Thailand from November 18-21, 2018. The first two days of the meeting mainly involved discussions on regional aquatic animal health and the current threat of emerging diseases. The last two days of the meeting dealt with the establishment of a regional collaboration framework. The main topics of discussion included the key work topics for this cooperation framework, the members to be included, and the proposed activities for each topic. Through the meetings, we were able to ascertain the aquatic animal health status of other countries in the region, to express our vision and needs for global emerging aquatic diseases, and improve infection prevention measures.
https://rr-asia.oie.int/en/events/1st-meeting-of-the-ad-hoc-steering-committee-of-the-regional-collaboration-framework-on-aquatic-animal-health/
https://enaca.org/?id=1094&title=report-of-the-18th-regional-advisory-group-on-aquatic-animal-health
[1]Spell out NACA.