"Seasonal influenza" refers to a type of flu that occurs during specific times of the year, typically during colder months. It is a common illness caused by a specific virus that spreads easily from person to person. Full definition
Older age and prior administration of seasonal influenza vaccine were independently associated with a decreased antibody response. (sciencedaily.com)
This virus is spreading from person - to - person worldwide, probably in much the same way that regular seasonal influenza viruses spread. (travelinsurancereview.net)
These positions are subject to annual seasonal influenza vaccinations. (ziprecruiter.com)