The American Association of Swine Veterinarians has released its recommendations for vaccination of swine against influenza. "While humans have taken the approach of annual vaccine strain updates in attempts to minimize influenza illness and death, control of influenza in swine herds has been less flexible," says AASV. "Vaccination of swine with killed virus vaccines has been employed with varying degrees of success since the mid-1990s."

As more strains of swine influenza virus emerged, biological companies have added contemporary strains to their existing, commercially licensed vaccines, resulting in bivalent and trivalent vaccines carefully balanced to induce immunity to all subtypes of SIV in the vaccine. Alternatively, autogenous killed influenza virus vaccines have gained in popularity to better match the antigenic and genetic differences of new SIV strains when compared to the commercial vaccine virus strains.

A change in vaccine strain is generally recommended when issues such as antigenic correctness, timing, adjuvant, and co-infections have been properly addressed. More often, the decision to use an autogenous vaccine is driven by a need to more immediately respond with a specific and rapid solution to the problems unsolved by the use of commercial vaccines.

The AASV recommends:

  • Vaccination with currently approved vaccines for the control of swine influenza should continue to be used to control clinical signs of disease due to swine influenza virus as recommended on each product's label.
  • Vaccination of swine against the pandemic (H1N1) 2009 influenza virus should be implemented if scientific evidence demonstrates that vaccination reduces virus shedding and the risk of transmission to pork production personnel.
  • Increased funding and research on novel delivery methods and vaccines to rapidly develop and introduce safe, effective vaccines against novel influenza viruses that not only minimize the risk of transmission between species but also overcome maternal immunity.
  • Increased funding and research on the utilization of technologies, such as core matrix, that would enable the rapid updating of influenza vaccines to incorporate emerging strains, promote cross-protection against multiple influenza strains and facilitate the development of a differential vaccine.

Read the complete AASV Position Paper

Source: American Association of Swine Veterinarians