Field evaluation of the safety and immunogenicity of a classical swine fever virus E2 subunit vaccine in breeding and nursery animals on Jeju Island, South Korea.

Abstract

Purpose:

Classical swine fever (CSF) reemerged on CSF-free Jeju Island where vaccination is not practiced by the unintentional injection of a live attenuated vaccine (modified live attenuated vaccines-low-virulence Miyagi [MLV-LOM]) in 2014. Since the Jeju provincial authority is considering adopting a voluntary immunization policy using a CSF-E2 subunit vaccine to combat LOM-derived CSF endemic, this study aimed to evaluate in Jeju herds.

Materials and Methods:

Two vaccination trials using the Bayovac CSF-E2 vaccine licensed for use in South Korea assessed the safety and humoral immunity of the CSF-E2 vaccine in breeding (trial 1) and nursery animals (trial 2) under farm application conditions.

Results:

Neither local nor systemic (including reproductive) adverse effects were objectively observed in pregnant sows and young piglets following a respective vaccination regime at pregnancy or weaning, respectively. Trial 1 showed that sows immunized with the CSF-E2 vaccine possessed high and consistent E2-specific and neutralizing antibody levels. The CSF-E2 vaccine-immunized pregnant sows subsequently conferred appropriate and steady passive immunity to their offspring. In trial 2, a double immunization scheme of the CSF-E2 vaccine in piglets at 40 and 60 days of age could elicit a consistent and long-lasting adequate antibody response. Additionally, the two trials detected no Erns-specific antibody responses, indicating that CSF-E2 vaccine can differentiate infected from vaccinated animals (DIVA).

Conclusion:

Our trial data collectively provide invaluable information on applying the CSF-E2 subunit vaccine to circumvent the possible drawbacks associated with the MLV-LOM concerning the safety, efficacy, and DIVA, in the LOM-endemic field farms and contribute to advanced CSF eradication on Jeju Island.

• Authors: Guehwan Jang, Eun-Joo Kim, Seong-Cheol Cho, Sung-Up Moon, Byeong Soo Kim, Jinhee Kim, Kyoung Ju Jeong, Kyungok Song, Seong Hwan Mun, Won-Myoung Kang, Jonghoo Lee, Changnam Park, Hyoung-Seok Yang, Changhee Lee
• Journal: Clinical and experimental vaccine research (Clin Exp Vaccine Res) Vol. 11 Issue 3 Pg. 264-273 (Sep 2022) ISSN: 2287-3651 [Print] Korea (South)
• PMID: 36451667 (Publication Type: Journal Article)
• Copyright: © Korean Vaccine Society.