PMC:7519301 / 156-322 JSONTXT

{"project":"LitCovid-PD-CLO","denotations":[{"id":"T3","span":{"begin":45,"end":46},"obj":"http://purl.obolibrary.org/obo/CLO_0001020"},{"id":"T4","span":{"begin":82,"end":87},"obj":"http://purl.obolibrary.org/obo/NCBITaxon_10239"},{"id":"T5","span":{"begin":102,"end":103},"obj":"http://purl.obolibrary.org/obo/CLO_0001020"}],"text":"2, raises questions about the possibility of a universally effective vaccine. The virus can mutate in a given individual, and these variants can be propagated across "}