Division 1

In classical swine fever virus infected pigs, antibodies are usually detectable in serum samples from two to three weeks after infection. In pigs that have recovered from the disease, protective neutralising antibodies can be detected for several years or even for their lifetime. Antibodies are also sporadically detectable in the terminal stage of lethally diseased animals. In some pigs with chronic form of classical swine fever, antibodies might be detectable for a few days at the end of the first month post-infection.

Pigs infected in utero may be immunotolerant against the homologue classical swine fever virus and produce no specific antibodies. However, antibodies of maternal origin can be detected during the first days of life. The half-life of maternal antibodies in non-viraemic healthy piglets is about two weeks. If found in piglets older than three months, classical swine fever antibodies are very unlikely to be of maternal origin.