What is the clinical evidence from this study?

Study design: RCT. Population: African Swine Fever (n=81). Intervention: AVAC ASF LIVE vaccine vs. Sterile phosphate-buffered saline (PBS). Primary outcome: Survival rate post-challenge with highly virulent ASFV at 28 days post-vaccination.

What does this research mean for the field?

The AVAC ASF LIVE vaccine is safe, even at 100 times the protective dose, and provides up to 100% protective immunity against highly virulent genotype II African Swine Fever Virus in pigs for at least 150 days post-vaccination. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

January 1, 2025Transboundary and Emerging Diseases16 citationsOpen Access

Safety and Efficacy Profiles of the Live Attenuated Vaccine AVAC ASF LIVE for Preventing African Swine Fever in Pigs

NDNguyen Van DiepHung Yen University of Technology and Education NNNguyen Thi NgocHung Yen University of Technology and Education NĐNguyễn Văn ĐứcHung Yen University of Technology and Education

Key Result

The AVAC ASF LIVE vaccine provided 100% survival in pigs challenged with highly virulent genotype II African swine fever virus at 28 to 150 days post-vaccination, compared to 0% survival in controls.

Study Design

Type

RCT (n=81)

Randomization

Randomly assigned

Multicenter

PICO

Population

African Swine Fever (n=81)

Intervention / Comparator

AVAC ASF LIVE vaccine vs Sterile phosphate-buffered saline (PBS) (10^4 HAD50 (efficacy/duration) or 10^6 HAD50 (safety))

Primary Outcome

Survival rate post-challenge with highly virulent ASFV at 28 days post-vaccination

Main Result

Absolute Event Rate: 100% vs 0%

Limitations

MGF360-12L and β-GUS marker genes may have lower sensitivity compared to B646L for detecting ASFV.
qPCR-based DIVA strategies may be ineffective due to low or undetectable viremia in vaccinated animals.
Further extensive trials with a larger sample size are necessary to assess the reliability of DIVA markers.
Future studies should include virus isolation assays to confirm if ASFV remains infectious in vaccinated pigs.
The vaccine does not provide protection against the new highly pathogenic recombinant strain (rASFV GI/GII).

Abstract

African swine fever (ASF) is one of the most devastating diseases affecting the global pig industry. Therefore, the development of safe and effective vaccines is crucial in combating the virus. The AVAC ASF LIVE vaccine, produced from an attenuated genotype II ASF virus (ASFV) strain with the deletion of six MGF genes and cultured in a Diep's macrophage (DMAC) cell line, has been officially licensed for use and commercialization in Vietnam. This study evaluated the safety and efficacy of the AVAC ASF LIVE vaccine. In the safety experiment, pigs received a dose equivalent to 100 times the protective dose. In the efficacy experiment, control pigs and one-dose vaccinated pigs were challenged with a highly virulent p72 genotype II ASFV on day 28 post-vaccination. The duration of protective immunity was assessed by challenging pigs at various time points, from 2 weeks up to 6 months post-vaccination. Results showed that pigs given the 100-fold protective dose remained healthy with no abnormal signs. Significantly, 60% of vaccinated pigs survived the challenge 14 days after vaccination, and the survival rates reached 100% when challenged at 28, 90, 120, and 150 days post-vaccination (dpv). The vaccine effectively induced robust immunity, leading to a reduction in viral shedding and the persistence of viral DNA in vaccinated animals. In conclusion, the AVAC ASF LIVE vaccine has demonstrated safety and high efficacy in protecting pigs from genotype II ASFV infection.

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