Targetd Vaccine for African swine fever

An international team of scientists has released groundbreaking findings that could reshape the fight against African swine fever (ASF), one of the deadliest animal diseases threatening pig populations worldwide. Their study reveals that while a promising vaccine candidate offers strong protection against some strains of the virus, it fails to defend against others—underscoring the urgent need for region-specific vaccines.

The research, jointly led by the U.S. Department of Agriculture’s Plum Island Animal Disease Center and the International Livestock Research Institute (ILRI) in Nairobi, tested a live-attenuated vaccine known as ASFV-G-ΔI177L. The results confirmed that a “one-size-fits-all” approach will not work in controlling ASF across diverse regions, given the genetic diversity of the virus.

A Global Threat with Local Consequences

ASF is a highly contagious and often fatal disease affecting both domestic and wild pigs. No globally licensed vaccine currently exists, making outbreaks catastrophic for pig farmers and national economies alike. In Africa, where the disease remains endemic, smallholder farmers are the most vulnerable. For many families, pigs are a critical source of income and food, yet repeated outbreaks have wiped out herds, leaving communities struggling to rebuild.

Beyond Africa, the virus has spread across Asia and Europe in recent years, causing devastating economic losses. The ripple effects extend even further: in North America, the swine industry represents a cornerstone of the economy. In 2023, the U.S. pig sector generated more than USD 27 billion in gross receipts, while Canada’s industry contributed CAD 6.3 billion in 2024. The spread of ASF into these regions would have disastrous economic and food security consequences.

What the Study Found

The team’s trials tested the vaccine candidate against ASF virus strains from different African countries. The results were mixed:

• Strong protection: Pigs vaccinated and challenged with the same strain used in developing the vaccine remained healthy, while unvaccinated pigs quickly died.
• Partial protection: Roughly 80% of vaccinated pigs survived when exposed to a genetically different strain isolated in Ghana.
• No protection: The vaccine failed completely against strains from Malawi, Kenya, South Africa, and Uganda, even though it had triggered strong immune responses.

These results highlight the complex nature of ASF and the limits of existing classification systems. Traditionally, ASF viruses have been grouped using a single gene marker, p72. However, the study revealed that this method is insufficient. For example, two viruses with identical p72 sequences—Georgia2010 and Pret4—produced very different results in vaccinated pigs.

Farmers’ Voices from the Ground

For many pig farmers, these findings are not just scientific—they are deeply personal.

“When ASF struck our village, I lost 18 pigs in one week,” recalls Grace Nambiro, a smallholder farmer from Uganda. “For us, pigs are school fees and daily meals. Without them, we are left with nothing.”

In Kenya, Joseph Otieno, a young farmer, shares a similar story: “I had dreams of expanding my piggery business, but ASF destroyed my herd twice. If a vaccine really works here, it would mean hope for my generation.”

Such testimonies underline why scientists are emphasizing regional solutions. A vaccine that works in one country but fails in another cannot meet the urgent needs of farmers who depend on pigs for survival.

Rethinking Vaccine Strategies

To address this, USDA scientists developed a new classification method that examines the virus’s entire set of protein-coding genes. This whole-genome approach provides a more accurate way to predict how a vaccine will perform against different regional strains.

“Although much further corroborative experimental work is needed, the classification developed will likely be the only available rational approach for deciding vaccination procedures to control and manage ASF outbreaks,” explained USDA scientist Manuel Borca.

ILRI Senior Scientist Anna Lacasta added: “This research reinforces the need to rethink our ASF vaccine strategies. A one-size-fits-all solution is unlikely. We need targeted vaccines aligned with regional virus biotypes to maximize protection and control outbreaks. There is a pressing need to support the development and licensing of vaccines tailored to circulating ASFV biotypes.”

The Way Forward

The study’s findings make clear that ASF cannot be tackled through a single universal vaccine. Instead, researchers are calling for continued investment into region-tailored vaccines, as well as exploring new designs capable of offering broader protection. Strengthening local surveillance systems, sequencing ASF virus strains, and building vaccine manufacturing capacity in affected regions will be key steps toward managing the disease.

For smallholder farmers in Africa, especially women and youth who are heavily engaged in pig farming, the stakes are high. Protecting pigs from ASF not only safeguards food security but also secures livelihoods and economic resilience.

As the threat of ASF looms globally, this research represents a critical step forward. By shifting the focus toward precision vaccine strategies, scientists hope to provide farmers and industries with the tools they need to withstand and ultimately overcome one of the greatest challenges facing livestock today.

By:Florence Uwamaliya