None of the vaccines contain human cells. The Pfizer and Moderna vaccines are pure mRNA that was made in the lab. This process does not use any cells at all. The AstraZeneca and Janssen vaccines use an adenovirus to bring the spike protein gene to our cells. Viruses need to grow in cells. After the adenovirus used in the AstraZeneca and Janssen vaccines are grown, the virus is collected from the cells and purified. So there ONLY is virus, NO human cells, in the AstraZeneca and Janssen vaccine. The initial cell line for the AstraZeneca vaccine came from human embryonic kidney cells. However, those cells were obtained over 60 years ago. There are NO human cells in the finished product of either the AstraZeneca or Janssen vaccine.