Table 3.

Animal studies of hepatitis B single administration vaccines (SAVs).

SAV formulation	Immune response	Control	Duration	Model (route)	Ref.
HBsAg(7.5 μg) PLGA 50/50-COOH microspheres	Inferior results after the sixth week	2.5 μg HBsAg aluminium-vaccine at 0, 1, 2 months	4 months	Mouse (SC)	[68]
HBsAg(7.5 μg) PLGA 50/50 microspheres	Comparable serum antibody titres to control
HBsAg(7.5 μg) PLGA 75/25 microspheres
HBsAg(7.5 μg) mixture of PLGA 50/50, PLGA 75/25, PLGA 50/50 - COOH microspheres
HBsAg(30 μg) PLG505, PLG858 (<10 μm) and PLA208 (>10 μm) microspheres	Antibody response comparable to control	10 μg HBsAg aluminium-vaccine at 0, 1, 6 months	12 months	Mouse (IM)	[69]
HBsAg(30 μg) PLG505 (<10 μm) and PLG858, PLA208 (>10 μm) microspheres
HBsAg(20 μg) PLGA 50/50 with trehalose and Mg(OH)2 microspheres	Immune response comparable to the control	10 μg HBsAg aluminium-vaccine at 0 and 1 months	3 months	Guinea pig (SC)	[39]
HBsAg(20 μg) PLGA 50/50 with Mg(OH)2 only	Significantly lower immune response than the control
HBsAg(20 μg) PLGA 50/50 with trehalose only
HBsAg(10 μg) Alginate–chitosan–PLGA (50/50, 70/30) composite microspheres	Antibody levels comparable to control	5 μg HBsAg aluminium-vaccine at 0 and 1 months	3 months	Mouse (SC)	[70]
HBsAg(10μg) PLGA (50/50, 70/30) microspheres	Significantly lower at all sampling times
HBsAg(20 μg) adsorbed microspheres: PLGA 50/50	Comparable immune response	10 μg HBsAg aluminium-vaccine at 0 and 1 months	42 days	Mouse (SC)	[72]
HBsAg(20 μg) adsorbed microspheres: PLGA 75/25
HBsAg(1 μg) loaded PLA nanospheres	Inferior antibody titers	Total 1 μg HBsAg aluminium-vaccine at 0, 1, 6 months	6 months	Rat (IM)	[71]
HBsAg(1 μg) loaded PLA nanospheres with alum
HBsAg(1 μg) loaded PLA microspheres
HBsAg(1 μg) loaded PLA microspheres with alum	Comparable antibody titres to the control

Note: SC, subcutaneous; IM, intramuscular; HBsAg, hepatitis surface antigen; PLGA, poly lactic glycolic acid; PLA, poly lactic acid.