Here's a popular song from the time that mentions influenza, from the sheet music at Indiana University:

The Internet Archive has early recordings by Billy Murray and by Irving Kaufman. They both take some liberties with the printed lyrics.


TAKE YOUR GIRLIE TO THE MOVIES
(IF YOU CAN'T MAKE LOVE AT HOME)
Words by Edgar Leslie and Bert Kalmar, music by Pete Wendling, ©1919.

1. Beatrice Fairfax gives advice to anyone in love.
That's why Johnny Gray
Wrote to her one day:
"When I call to love my girl, her folks are always there.
That's why I'm blue.
What shall I do?"
And Beatrice said: "Never despair—

CHORUS: Take your girlie to the movies if you can't make love at home.
There's no little brother there who always squeals.
You can say an awful lot in seven reels.
Take your lessons at the movies and have love scenes of your own.
When the picture's over and it's time to leave,
Don't forget to brush the powder off your sleeve.
Take your girlie to the movies if you can't make love at home.

2. Sweethearts always used to spoon in a big Morris chair.
Young folks of today
Have a diff'rent way.
Far away from a cranky dad and mother's eagle eye,
It's lots of fun.
Here's how it's done,
So come on and give it a try:

CHORUS: Take your girlie to the movies if you can't make love at home.
Pick a cozy corner where it's nice and dark.
Don't catch influenza kissing in the park.
Take your lessons at the movies and have love scenes of your own.
Though she's just a simple little ribbon clerk,
Close your eyes and think you're kissing Billie Burke.
Take your girlie to the movies if you can't make love at home.