For what it's worth (October 2024), I had a sudden drop in iron, hgb, saturation and ferritin around August 2021, after the Pfizer. I strongly suspected it might be the vaccine because all my life my iron numbers have been on the high side. I was even seeing a hematologist for this. But after the vaccine, my ferritin dropped to below detectable levels on the blood test. I had bloodwork done every 6 months from that time on. Rock-bottom inflammation markers. I refused to take iron supplements or get an infusion because I had no symptoms and I wanted to find out the root cause. I still have not figured out what happened.