Hi mummyT, my eldest son has this vomiting issue during infant stage.
The vomiting started from 2nd week of birth, vomited 3-4 times a day out of 7 feeds.
Doctor says it is reflux and there is no medicine for it.
At least can rest assure after doctor's confirmation that it is not any health threatening issue.
It carried on and as baby grew, the vomiting lessen and it eases after 5 months old.