<http://ns.inria.fr/covid19/PMC5053509#body_text>	<http://purl.org/dc/terms/subject>	"1835 in science" .
<http://ns.inria.fr/covid19/PMC5053509#body_text>	<http://purl.org/dc/terms/subject>	"1834 in science" .
<http://ns.inria.fr/covid19/PMC5053509#body_text>	<http://purl.org/dc/terms/subject>	"Smallpox vaccines" .