These graphs don't quite tell me enough. It's a complex problem and even with margins of error for varying health condition I'd expect at least a 3d projection

These graphs don't quite tell me enough. It's a complex problem and even with margins of error for varying health condition I'd expect at least a 3d projection to be required to map between age, time (since 'full inoculation') and risks of illness / disease / hospitalization / death. I have also heard that lifestyles which encourage sitting all day and correlate strongly with lower fitness and higher carried fat are increased risk factors. I guess I'd appreciate a formula from the FDA and CDC that tells me roughly what time frame they recommend a (regular interval?) booster shot, rather than some oversimplified coarse number.