I believe you are correct. Ive had many people say to me, oh, Ive got the flu, have a really sore throat and runny nose, but I went to work when in fact what they probably had is a head cold. Not to say that bad head cold wont make you feel pretty miserable or even compel you to stay home from work for a day, but the difference is that a flu often comes on very suddenly as opposed to a common cold, and with the flu, you tend to run a fever, sometimes high and have extreme body aches and fatigue, and by fatigue, I mean, cant hardly get out of bed or lift your head off the pillow sort of fatigue.
I get wintertime allergies. When it comes on it comes on fast and feels a lot like the flu, I start out sneezing like crazy, eyes water, nose runs and I even get body aches and sometimes feel hot and flushed but typically do not run a fever. The way I know it was an allergy attack is that it goes away completely in about 24-hours. The last time I had the flu, I was in bed for 5 days, missed 4 days of work and it took another 5 days or so before I felt well again.
I searched for this and could not find it here in the US. However I did find some in New Zealand. I purchased it online here without any scary things happening to the credit card.
It is available also in France and a few other countries but I was most comfortable ordering it from this place.
Maybe this will be helpful for you. My fall allergy season was far less horrid thanks to this stuff, imo.