Abstract
The general public in the United States has heard a great deal about the threat of a global pandemic with the capacity to kill millions. Influenza is often mentioned in this context with frequent references to the devastating 1918 influenza pandemic. Furthermore, outbreaks of West Nile virus, Zika virus, and Chikungunya virus have all caused public concern. But the U.S. public has tired of this issue, possibly due to the failure of any major pandemics to emerge over the past two decades. It is probably not surprising, therefore, that recent reports of an ongoing pandemic caused little more than a ripple in public consciousness. I refer, of course, to reports that a current outbreak of African swine fever (ASF) that may kill a full one-quarter of all pigs in the world with severe economic consequences for affected countries.
The ASF outbreak began approximately a decade ago when the African swine virus spread from Africa to several Eastern European countries and then to Asia. It subsequently reached >50 countries around the globe and is now a significant threat to the world's production of pork. It has had particularly severe effects in China, which is a major consumer of pork product; China is thought to have lost upward of 100 million pigs since the outbreak began. There are fears that the pandemic will soon hit the United States.
ASF was identified in 1921 as the cause of an endemic infection of pigs in sub-Saharan Africa. The virus does not transmit to humans, but causes an acute disease in pigs and is usually fatal within a week of infection. Disease symptoms include a failure to thrive and the induction of abortion in pregnant sows. As such, the virus has significant economic impacts on all pig producers, large and small.
The primary mode of viral spread is through the transportation of infected pigs and through the sale of infected feed. Control of the infection is challenging because pigs are frequently raised in small farms and homes in many countries. Consequently, the disease is often under-reported (or not reported at all, an example being North Korea). The problem is compounded by the fact that the virus also establishes infection in wild pig populations.
Current control of the pandemic focuses on prevention, early detection, and slaughter of infected animals, all of which can be problematic in low- and middle-income countries. Clearly, there is an urgent need for an effective ASF vaccine. But the virus poses a severe challenge to vaccinologists and classical approaches to generate ASF vaccines have not worked. The reasons for this are numerous. The virus has a large genome (190 kb) that codes for nearly 170 proteins. Moreover, ASF virus infects macrophages and induces the death of uninfected B and T lymphocytes, effectively destroying the immune system. The virus is also very stable and able to persist for substantial amounts of time in the environment.
Here at Viral Immunology, we are calling for research on the development of an effective ASF vaccine. As a leading journal that addresses veterinary viral immunology, the journal commits to publishing articles on the topic of ASF virus immunology and vaccine development. Please submit your articles on this topic through the journal's website.