Is it safe to get prevenar 20 vaccine while taking long term prednisone for polymyalgia. i have been taking 5 months started at 15mg. have been weaning down per doctor on 7.5 mg for 3 weeks than 7 for 3 weeks. and continue to go down 1 mg?

I would wait for a month after completing the wean and then get the vaccine. You could take it earlier with less long term benefit, but this delay would make it more likely you would get the most benefit out of the shot. In theory you could take it now and get it again in 6 months, which would boost any early benefit, however, I don't think insurers would cover it that way.