Re-assembly of nineteenth-century smallpox vaccine genomes reveals the contemporaneous use of horsepox and horsepox-related viruses in the USA

Table 1 Genomic features of the re-assembled genomes of VK01, VK02, VK05, VK08, and VK12 vaccines

Sample ^a(year)		Genome size (bp)	ITR size (bp)	ORFs (no.)	Genome coverage (fold)	% identity HSPV MNR-76		^cPresence of the deletions in the genome’s left and right ends characteristic of all VACV strains but absent in HSPV
						Whole genome	^bConserved core region
Horsepox-related virus with VACV-like genome ends	VK01 (1866)	214,388	22,960	248	1762	0.903	0.997	Yes
Horsepox-related virus with VACV-like genome ends	VK08 (1873)	204,481	9070	240	746	0.943	0.997	Yes
Horsepox-related virus with one genome end similar to VACV	VK02 (ND)	199,509	616	236	662	0.889	0.995	Deletion in the left end only
Horsepox-related virus with one genome end similar to VACV	VK12 (1859)	219,647	23,165	253	937	0.856	0.997	Deletion in the right end only
Horsepox virus	VK05 (ND)	212,688	6935	236	946	0.997	0.998	No
Horsepox virus	^dHSPV MNR-76	212,633	7527	236	ND	1	1	No

^aYears according to Duggan et al. [7]. ND means not determined
^bThe conserved core region refers to approximately 99.0000 bp spanning from genes F9L to A24R
^cThe deletions correspond to 10.7 kb and 5.5 kb stretches of DNA present in HSPV-MR76, but absent in all VACV strains and in the Mulford 1902 [4, 5]
^dHorsepox virus strain MNR-76 was included for the sake of comparison [5]. GenBank accession numbers are indicated in the “Availability of data and materials” section

ISSN: 1474-760X