Future perspectives on swine viral vaccines: where are we headed?

Table 2 Simplified advantages and disadvantages of traditionally used, widely available viral attenuated-live and inactivated vaccine types in pigs

	Attenuated-live	Inactivated
*Administration routes*	(IM), oral, intranasal, intradermal	IM, intradermal
*Adjuvant*	None	Required
*Number of doses*	One dose	Often two doses
*Humoral immunity*	IgG	IgG
*Secretory immunity*	IgA	–
*Cellular immunity*	Yes	–
*Long-term immunity*	Yes	–
*Reversion to virulence or recombination*	Yes	Not possible
*Storage*	Heat-labile^a	Stable^b
*Transmission among pigs*	Yes	No
*Production cost*	Low (involves only culture, bottling and lyophilization or freezing)	High (requires a high antigen content, addition of adjuvant and other excipients)
*Time until a vaccine is available*	Months to years	Months

^aNeeds to be stored at −80 °C or lyophilized. Cannot be stored once opened
^bStorage at room temperature or at + 4 °C (never frozen) for longer periods; can be used for some time after opening a bottle. Phase separation of the aqueous and oil phases in the vaccine formulation may be observed in some vaccines, which can be corrected by vigorous shaking of the vaccine container

ISSN: 2055-5660