ASF-Resistant Pig Breeds: CRISPR and Genetic Progress 2026

African swine fever (ASF) has become one of the most persistent threats to the global pig industry since its major outbreaks in Asia during 2018–2019. ASF causes high mortality, spreads quickly, and creates major losses for both industrial farms and smallholder pig producers.

Existing ASF vaccines are an important step forward, especially for countries facing long-term disease pressure such as Vietnam. However, vaccines cannot completely replace biosecurity, epidemiological surveillance, transport control, and herd management. For this reason, the international scientific community is also studying long-term approaches such as CRISPR gene editing and genetic selection to develop pig populations that may have better tolerance to ASF in the future.

African swine fever virus (ASFV) belongs to the Asfarviridae family. It is a double-stranded DNA virus with a complex structure and a large genome. ASFV can attack important immune cells, including macrophages, and has multiple mechanisms to evade the host’s immune response.

What makes ASFV especially difficult to control is that protective immunity against this virus is highly complex. An antibody response alone is often not enough to provide strong protection, unlike many other viral diseases. This is one of the reasons why developing a safe, effective, and stable ASF vaccine at scale has been challenging for a long time.

Domestic pigs are highly susceptible to ASFV and do not have a clearly defined natural tolerance mechanism like some African wild pig species. Some species, such as warthogs and bushpigs, can become infected with or carry ASFV without showing severe disease, while soft ticks of the genus Ornithodoros act as natural vectors in the transmission cycle in some regions. This difference has drawn scientific interest in the genetic basis of natural ASF tolerance.

In Vietnam, the first ASF outbreak in February 2019 spread to all 63 provinces and cities within a short period of time. Millions of pigs had to be culled, the national pig herd dropped sharply, and pork prices rose significantly during 2019–2020.

Although the pig herd gradually recovered afterward, ASF has continued to recur in cycles in many localities. This shows that ASF is not a short-term risk, but a long-term challenge for the pig industry.

Vietnam has licensed domestic ASF vaccines such as NAVET-ASFVAC, AVAC ASF LIVE, and Dacovac-ASF2. This is an important step forward, but vaccines remain only one part of an overall strategy. Real-world effectiveness still depends on the target animals, circulating virus strains, storage conditions, application procedures, vaccine coverage, and how well biosecurity is maintained on farms.

For this reason, research into pig breeds with better ASF tolerance still has long-term strategic value. However, this field remains at the research stage and is not yet an available solution for farmers today.