J&J was the initial vaccine planned, as its weaker effectiveness against spread of Delta was discovered, they moved to favouring Pfizer and Moderna. While there

J&J was the initial vaccine planned, as its weaker effectiveness against spread of Delta was discovered, they moved to favouring Pfizer and Moderna. While there was a decent rollout of J&J prior to that, the biggest group of J&J vaccinations was after they made that decision, they gave young people the option of going to a chemist to get a J&J vaccination ahead of schedule to deplete their stock while the regularly scheduled rollout continued with Pfizer and Moderna. I think people who originally got J&J did get the option to get Pfizer later.