This is first time read and found out there is a senior flu vaccine dose in pharmacy. since seniors were having all these years the regular flu vaccine, will it be okay to try the high dose flu vaccination in case if the dose cause any side effects?

The higher dose flu vaccine for those over 65 years old has been given for many years now-it is not new! People over 65 typically don’t mount the same immune response as younger people so a higher dose allows a better immune response, thus increasing protection against influenza. The side effects are similar to the regular flu vaccine so the side effects you typically get, if any, can occur.