Table 2.

Comparison of recombinant hepadnavirus vector designs.

Representative Publication(s)	Obliterated ORF(s)	cccDNA Pool Expansion 1	Progeny Virus Production 2
Chaisomchit et al., 1997 [31]	None	Self-sufficient	Self-sufficient
Wang et al., 2013 [36]
Hong et al., 2013 [37]	S	Self-sufficient	Requires help
Wang et al., 2002 [32]	C	Requires help	Requires help
Yoo et al., 2002 [33]
Deng et al., 2009 [34]
Wang et al., 2014 [35]
Bai et al. (submitted)	C/S	Requires help	Requires help
Chaisomchit et al., 1997 [31]	P	Requires help	Requires help
Protzer et al., 1999 [17]	P/S	Requires help	Requires help
Chang et al., 1990 [30]
Nishitsuji et al., 2015 [40]	P/C	Requires help	Requires help
Untergasser et al., 2004 [38]	All	Requires help	Requires help
Liu et al., 2013 [39]

¹ vectors with functional C and P ORFs are expected to be able to replicate self-sufficiently and form additional cccDNA in infected cells which would, in turn, result in higher cargo gene expression. ² vectors retaining all functional viral ORFs are expected to be able to replicate self-sufficiently and produce infectious progeny recombinant viruses, which would in turn result in infection of additional susceptible cells. Requires help: trans-complementation of obliterated proteins by a co-infecting wild-type virus is required for indicated functions.