African horse sickness (AHS) is a serious and often fatal viral disease affecting horses in Africa, caused by the dsRNA orbivirus African horse sickness virus (AHSV). Although vaccination is the most effective weapon in battling AHS, the available vaccine is a live-attenuated version of the virus (LAV). This constraint spurred attempts to develop an alternative vaccine.

The team of Susan J. Dennis from the University of Cape Town in South Africa reports a plant-based production of a virus-like particle (VLP) AHSV serotype five candidate vaccines. The team transformed AHSV capsid proteins into tobacco (Nicotiana benthamiana) via Agrobacterium-mediated transformation. The vaccine was extracted and purified from the leaves of tobacco plants containing all four capsid proteins.

Guinea pigs were used to test the ability of the plant-produced AHSV vaccine to induce an immune response. Five guinea pigs were each treated with AHSV vaccine. All vaccinated guinea pigs showed a level of neutralization capability against AHSV. These results indicate that plant-produced AHSV vaccine can stimulate a high immune response in guinea pigs.

This study is the first reported of AHSV vaccine produced in plants, which has important implications for the fight against AHSV.

For more information, read the article in Plant Biotechnology Journal.