Assertion: flu | /r/CreatedBy | influenza b virus
Facets:
Source sentences:
text: The quadrivalent influenza vaccine licensed by the CDC is currently designed to protect against both co-circulating lineages and has been shown to have greater effectiveness in prevention of influenza caused by Influenza B virus than the previous trivalent vaccine.
text: Influenza , commonly known as the " flu ," is an extremely contagious respiratory illness caused by influenza A or B viruses.