Husband (age 39) and i (age 33) had covid in dec '20. he was hospitalized but my experience was mild. we did a semi quantitative antibodies test aug '21. my result was 97 and his was 588. is this a good range for protection against reinfection?

It is great that you have antibody present in your system seven months after the infection. Yet you both should get vaccinated as antibodies produced in the body is different than natural immunity and these augment protection. Hope it helps.

Get vaccinated. Natural infection may not protect you against variant strains. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Wish you good health!