PMC:7738161 / 37727-37923 JSONTXT

{"project":"LitCovid-sentences","denotations":[{"id":"T255","span":{"begin":0,"end":196},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"We therefore suggest that there is an urgent need for longitudinal measurements of population-level prevalence and immunity via viral testing and serological studies, even where prevalence is low."}