If you vomit intentionally after eating undercooked fish can that prevent food poisoning?

Anisakiasis: Anisakiasis is the principal "worm" infestation of the stomach, caused by ingesting anisakis larvae in raw or undercooked fish. Within a few hours, there is severe upper abdominal pain, nausea, vomiting (relieved after endoscopic removal of worm). As you know, raw fish (sushi, sashimi) are increasingly popular--choose carefully your source of fish (farm raised, not wild caught) & food preparer.