How has the flu been affected by the lack of people getting it?

Oy vay. Similarities: Both COVID-19 and flu can have varying degrees of signs and symptoms, ranging from no symptoms (asymptomatic) to severe symptoms. Common symptoms that COVID-19 and flu share include:

Fever or feeling feverish/chills Cough Shortness of breath or difficulty breathing Fatigue (tiredness) Sore throat Runny or stuffy nose Muscle pain or body aches Headache Some people may have vomiting and diarrhea, though this is more common in children than adults

Re: False positives (these were just the first hits I found, not necessarily the best):

/r/askscience Thread Parent