Catholic leaders and anti-abortion groups have raised objections to the use of fetal cells, a process common in vaccine development since the 1960's, in the development of the COVID-19 vaccines. A recent bill passed by Michigan Republicans requires that any resident receiving the Johnson & Johnson COVID-19 vaccine be told that it was developed using a stem cell line originating from an aborted human fetus. In response to concerns raised over the COVID-19 vaccines, the Michigan Department of Health and Human Services has issued a statement saying that COVID-19 vaccines do not contain fetal cells. Some COVID-19 vaccines, however, do use a historic fetal cell line in production and manufacturing, the statement said. Johnson & Johnson (Janssen) used a fetal cell line to produce and manufacture their COVID-19 vaccine. Pfizer and Moderna did not use a fetal cell line to produce and manufacture their COVID-19 vaccines, however, a fetal cell line was used in a very early phase to confirm efficacy prior to production and manufacturing. COVID-19 Vaccines do not contain DNA or fetal cells, even if a fetal cell line is used during any part of development, the MDHHS said. Cells that make up the "cell lines" used for certain COVID-19 vaccine development came from two elective pregnancy terminations that occurred in the 1970s and 1980s. Those individual cells from the 1970s and 1980s have since been grown in the lab for 30 to 40 years, creating fetal cell lines. Current fetal cell lines are generations removed from the original fetal tissue and they do not contain any tissue from a fetus. These same cells from the '70s and '80s continue to grow in a lab as a cell line. Fetal cell lines are used in other medical technologies, as well, as this process is not new. Viruses that infect humans tend to grow better in cells from humans than animals. Historic cell lines are used to grow the vaccine virus because the fetal cells can divide many times and can be used longer than other cell types. They are stored at low temperatures, allowing a cell line to be used from decades ago. Once the virus is grown, any cellular debris is removed. Vaccines do not contain DNA or fetal cells, the statement said. On March 2, leaders in the Roman Catholic Church released a statement saying that it's "morally acceptable" to receive the vaccine.