About: http://webisa.webdatacommons.org/394570864

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	We do not know yet how much of the year-to-year variation can be explained by climatic conditions or other factors, such as acquired immunity in birds or humans.
http://www.w3.org/ns/prov#wasQuotedFrom	medicalxpress.com