text: Adenoviral Vector DNA and SARS CoV 2 mRNA Based Covid 19 Vaccines Possible Integration into the Human Genome Are Adenoviral Genes Expressed in Vector based Vaccines Vigorous vaccination programs against SARS CoV 2 causing Covid 19 are the major chance to fight this dreadful pandemic The currently administered vaccines depend on adenovirus DNA vectors or on SARS CoV 2 mRNA that might become reverse transcribed into DNA however infrequently In some societies people have become sensitized against the potential short or long term side effects of foreign DNA being injected into humans In my laboratory the fate of foreign DNA in mammalian human cells and organisms has been investigated for many years In this review a summary of the results obtained will be presented This synopsis has been put in the evolutionary context of retrotransposon insertions into pre human genomes millions of years ago In addition studies on adenovirus vector based DNA on the fate of food ingested DNA as well as the long term persistence of SARS CoV 2 RNA DNA will be described Actual integration of viral DNA molecules and of adenovirus vector DNA will likely be chance events whose frequency and epigenetic consequences cannot with certainty be assessed The review also addresses problems of remaining adenoviral gene expression in adenoviral based vectors and their role in side effects of vaccines Eventually it will come down to weighing the possible risks of genomic insertions of vaccine associated foreign DNA and unknown levels of vector carried adenoviral gene expression versus protection against the dangers of Covid 19 A decision in favor of vaccination against life threatening disease appears prudent Informing the public about the complexities of biology will be a reliable guide when having to reach personal decisions about vaccinations 