The porcine reproductive and respiratory syndrome quandary. Part II: Vaccines and vaccination strategy

The first vaccine to aid in the prevention of the porcine reproductive and respiratory syndrome (PRRS) was registered for use in Spain in 1994. It comprised an inactivated European strain of PRRS virus (PRRSV) that had been propagated in porcine alveolar macrophages. Later in the same year, the first attenuatedvirus vaccine became commercially available in the United States.1 It comprised a North American strain of PRRSV that had been propagated in an established monkey kidney cell line. Since 1994, a number of additional vaccines (comprising either attenuated or inactivated PRRSV) have been developed in both the United States and Europe. Each includes a different strain of the virus of either the North American or European genotype (Table 1).