There is an argument within the field of genetics that our genes do not determine our health, rather it is our environment that impacts our health.
Nature vs. Nurture is not an absolute, meaning it's not a binary cause, either genetics or environment. Human diseases can be complex and have both genetics and environmental influences. Those who say genes do not determine our health are narrow minded in the same way those that say genes control everything about us are also narrow minded. Each health issue or disease should be considered on a case by case situation. Identical twins have the same genome ( albeit different epigenome) but can have different health status eg. one east potato chips and watches TV all thetime vs. one who eats whole foods and exercises. In this case, yes environment is the major influence. But someone who has a causative mutation in the Huntington's gene will develop the disease. In this case genetics is the major influence. So vaccines may impact individuals differently based on the person's genetic make up.
Your genetic makeup (genome) is important- yes the environment can influence it but ultimately it is what genes you have that can be influenced. Great post!
Cheers!
Ian