Chinese scientists have unravelled the three-dimensional structure of African swine fever virus, laying a solid foundation for developing effective and safe vaccines against the disease.

The research, jointly conducted by scientists at the Institute of Biophysics of the Chinese Academy of Sciences (CAS) and the Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences (CAAS), Shanghai Tech University and other institutes, was published in the latest issue of the academic journal “Science”.

The scientists successfully isolated the epidemic strain of the African swine fever virus. It took the research team four months to collect over 100 TB of high-quality data.

The research shows the virus has a unique structure of five layers: the outer membrane, capsid, double-layer inner membrane, core-shell and genome.

It contains more than 30,000 protein subunits, forming a spherical particle with a diameter of about 260 nanometers.

The study has identified the structural proteins of the virus, revealing potential protective antigens and key information on the epitope, the part of an antigen molecule to which an antibody attaches itself.

The research also shows the complicated arrangement and interaction mode of the structural proteins and proposed a possible assembly mechanism of the virus to provide an important clue as to how it invades host cells and evades and antagonizes the host antiviral immunity.

African swine fever, first described in Kenya in 1921, is a highly contagious viral disease of swine with mortality rates approaching 100 percent. Over the past decade, the disease has spread through many countries, posing a serious risk of further expansion.

During the period from January to October 2019, the World Organization for Animal Health was notified by 26 countries of new or ongoing outbreaks: 13 in Europe, 10 in Asia and three in Africa.

With no vaccine or treatment available, culling pigs is the most effective way to contain the outbreaks, more than 30 million pigs have been culled during 2018 and 2019.