Table 1.

Recent vaccine antigens expressed via the plant nuclear genome that report immunogenicity or protection (for full length table see Online Supplementary Table S1)

Antigen	Expression system	Expression level	Functional evaluation	Refs
Human vaccines (Stable expression)
Bacterial antigens
Enterotoxigenic E. coli Heat-labile toxin B subunit (LTB)	Carrots	0.3% TSP	Immunogenic and protective against CT challenge	[15]
	Soybean	2.4% TSP	Immunogenic and partial protection against LT challenge in mice	[4]
Cholera toxin B subunit (CTB)	Tomato	0.081% TSP	Immunogenic by oral delivery to mice	[79]
	Rice	2.1% TSP	Immunogenic and protective against CT challenge to mice following oral administration	[16]
Viral antigens
Hepatistis B virus surface antigen	Potato	8.5 μg g−1 FW	Immunogenic response in humans following oral administration	[19]
Hepatitis B virus surface antigen fused with preS1 epitop	Rice	31.5 ng g−1 DW	Immunogenic by intraperitoneal delivery to mice	[80]
Human group A rotavirus (VP6) protein	Alflfa	0.06-0.28% TSP	Immunogenic in mice and offspring developed less severe diarrhea after challenge with simian rotavirus SA-11, indicating that antibodies generated in the dams provided passive heterotypic protection to the pups	[81]
Rotavirus (VP7)	Potato tubers	0.3-0.4% TSP	Immunogenic in mice following oral delivery. Neutralization activity against rotavirus	[82]
Norwalk virus capsid protein	Tomato Fruit and Potato	8 and 0.4% TSP	Elicit systemic and mucosal antibody responses in mice following oral administration	[21]
SARS-CoV S protein (S1)	Tomato and tobacco leaf	0.1% TSP	Immunogenic to mice following oral administration	[83]
Smallpox recombinant vaccine virus B5 antigenic domain (pB5)	Tobacco and Collard leaf	Not Reported	Antibody response in mice immunized parenterally and protects against lethal dose of vaccinia virus	[84]
Japanese encephalitis virus (JEV) envelope protein (E)	Rice	1.1-1.9 μg mg−1 TSP	JEV specific neutralizing antibody detected in mice following intraperitoneal or oral administration	[85]
Protozoan antigens
Plasmodium yoelii merozoite surface protein (PyMSP4/5)	Tobacco	0.02-0.04% TSP	Induces antigen-specific antibodies in mice following parenteral delivery	[86]
Human vaccines (Viral/Transient expression)
Bacterial antigens
Yersinia pestis F1 and LcrV antigens	Tobacco leaf tissue	380 and 120 μg g−1 FW	Immunogenic and protective in monkeys against Y. pestis following subcutaneous injection	[57]
Yersinia pestis F1-V antigens	Tobacco leaf	1 and 2 mg g−1	Immunogenic and protection in vaccinated guinea pigs against Y. pestis aerosol challenge	[26]
Viral antigens
Smallpox recombinant vaccine virus B5 antigenic domain (pB5)	Tobacco leaf	Not Reported	Antibody response in mice immunized perenterally and protective against lethal dose of vaccinia virus	[84]
Encoding domain III of the dengue 2 envelope protein (D2EIII)	Tobacco	0.28% TSP	Retains antigenicity and immunogenicity as well as inducing neutralizing antibodies in vaccinated animals.	[87]
HIV entry inhibitors red algal protein griffithsin (GRFT)	Tobacco (TMV)	1 g kg−1 FW	Active against HIV at picomolar concentrations, directly virucidal via binding to HIV envelope glycoproteins and capable of blocking cell-to-cell HIV transmission	[75]
Pathogenic avian influenza virus (H5N1 subtype)	Tobacco	60 mg kg−1	Immunogenic in mice and ferret and also protects ferrets against challenge infection with virus	[28]