Immunization of horses with a polyvalent live-attenuated African horse sickness vaccine: Serological response and disease occurrence under field conditions

Publication date: 2015 Source:Trials in Vaccinology, Volume 4 Author(s): Umberto Molini , Giuseppe Marucchella , Adrianatus Maseke , Gaetano Federico Ronchi , Mauro Di Ventura , Romolo Salini , Massimo Scacchia , Attilio Pini African horse sickness (AHS) is a non-contagious, insect-borne disease of equids caused by a RNA virus (AHSV), which belongs to the genus Orbivirus, family Reoviridae. The disease is endemic in sub-Saharan and western Africa, where prevention strictly depends upon vaccination. The present paper aims at evaluating the serological response and the occurrence of AHS in horses bred under field condition and regularly immunized using the commercially available live attenuated vaccine (LAV) produced by Onderstepoort Biological Products. The study was carried out in a farm located in the district of Windhoek (Namibia), where the disease is endemic. A total of 72 cross-breed horses, out of the 150 housed on the farm, were subdivided in six age groups, from 2 to 7years-old. Each group consisted of 12 heads which were born during the same breeding season and had undergone from four to nine vaccination courses. AHSV specific immune response was evaluated by serum-virus neutralization test. Data about the clinical occurrence of the AHS from 2006 to 2011 were made available. The immune response, in terms of number of seropositive horses and serum neutralizing titers, was quite variable among horses and against different serotypes. Neutralizing antibodies ...
Source: Trials in Vaccinology - Category: Infectious Diseases Source Type: research