I'm a 40-year-old female with beta thal intermedia and got two doses of Moderna COVID vaccine earlier this year (first dose in late March, second dose in May). It was fine! I had a very small rash near the injection site a few days after getting the vaccine, which is a normal reaction for the Moderna vaccine. My upper arm near the injection site was also sore for about 36 hours, which is about the same as what I've experienced with other vaccines (flu, TDAP, etc.). I didn't notice any other side effects. My dad, who also has beta thal intermedia, got the same vaccine and said he felt tired in addition to the sore arm. He is 70. He didn't have any other side effects.
At the time I got the vaccines, my hemoglobin was about 9 (normal for me) and my ferritin was about 650 (ferritin has gone up since but that's part of a long-term trend over the past few years so I'm certain it has nothing to do with the vaccine).
My own perspective is that a COVID infection would be significantly higher risk for me than taking the vaccine, which is one of the most effective, most widely administered vaccines in history at this point. mRNA vaccines (Pfizer, Moderna) are even safer than traditional vaccines, so I was very comfortable taking the vaccine!