It’s true that all kinds of things can change the expression of our dna (phenotype) but my concern is changes of dna at the base layer (genotype). Before planning to have children, people should get healthy. They should detox from processed foods and reduce exposure to stress and pollution. But that stuff we can still control. Things we can’t really control at the moment are the genotype. For example, humans still have tails in our dna but it is inactive. What if the vaccine makes some important part of our dna inactive? Like the ability to reduce inflammation at the heart?