Last time for me was about 4.5yrs ago. 17wks pregnant with dd and had an awful, awful chest infection that almost landed me in hospital.
Dr (4) and ds (18mths) have both never needed any though ds did receive 1 dose via his iv as precaution when he had an op at 8mths
Eta: actually just remembered I had ab's after my cs with ds. Somehow got an infection in my hand where my cannula went in