Contemporary vaccines against Porcine Reproductive and Respiratory Disease Syndrome viruses (PRRSV) and Swine Influenza viruses (SIV) are composed of either live attenuated viruses that risk frequent recombination between viral and vaccine strains and reversion to virulence or inactivated viruses
that confer short term immunity.
The three vaccines currently available in the United States are all inactivated viruses
are all inactivated viruses
. Do not inject them in the gluteal area, he warned, as it has been associated with prophylaxis failure.
"Most current vaccines are produced from live inactivated viruses
. These vaccines can result in the virus persisting in the flock and potentially re-emerging to cause disease later on.
The clinical trials in these instances used inactivated viruses
as vectors to shuffle genes into patients' cells.