Boars immune to ASF discovered in Latvia

Wild boars in Latvia that have managed to survive the African swine fever (ASF) and develop antibodies against it have been found in Latvia, raising hopes for the development of a vaccine against the disease. 

“This year, 5% of shot boars had antibodies to ASF, which means that these animals managed to survive the infection and even gain immunity. Apparently, it was a particularly hardy specimen. This is something new for us, but it is clear that this disease is still not fully understood and this is a complex phenomenon,” said general director of Food and Veterinary Service Maris Balodis.

At the same time he raises concerns, as the situation with ASF in the country continues to deteriorate rapidly, which poses a serious threat to the domestic pig sector.

“ASF gradually covers the whole of territory Latvia, and the next year we will face a big problem when the infection will inevitably appear in the forests of Kurzeme, where the largest number of wild boars - 20 animals per square kilometer. If ASF gets here, it will be very bad. Meanwhile, 75% of farms in Kurzeme do not comply with the necessary measures of biological security,” he added.

Balodis believes that one of the most efficient ways to protect farms is to reduce the population of wild boars, and the government should encourage hunters to actively shoot them.

Further verification is needed

Russian veterinary experts have noted that the finding needs further verification. “Previously some of the animals had survived the acute phase of the disease, while remaining carriers of the virus. We have no information as to exactly what kind of immunity we are talking about, and whether these antibodies could be used for vaccine development,” commented the spokesperson of the Russian veterinary body Rosselhoznadzor.

Meanwhile, number of Russian scientists expressed doubts that antibodies can be used for future production of vaccine. “In general, neutralizing of ASF virus with antibodies is impossible because the virus enters the target cells such as monocytes amd macrophages by phagocytosis regardless of specific receptors,” explained Professor Vladimir Makarov from the All-Russian Research Institute of Veterinary Virology and Microphytology.

Russian scientists are engaged in active development of a vaccine since 2013. In 2014 it has been reported that the first trials of vaccine has been successfully finished, and the first results were encouraging.

It is expected that the vaccine can be wiped out by mid-2016. In early 2015, Russian scientists were also able to identify the gene of ASF, which also believed to be important milestone in terms of fighting the disease.