President Donald Trump’s announcement Wednesday that scientists who work for the government can no longer conduct research that uses human fetal tissue is being hailed by anti-abortion groups.

But the policy does not apply to privately funded fetal tissue research, and the Health and Human Services Department said that, at least for now, the change will not affect universities that use government funding for fetal tissue research. Nor will it change the fact that research using fetal tissue has yielded advances — particularly vaccines — that save lives and have helped decipher biological mysteries.

Some examples:

  • During a U.S. epidemic of rubella (German measles) in the mid-1960s, about 31,000 pregnant women infected with the virus suffered stillbirths, gave birth to severely disabled infants, or decided to end their pregnancies. One aborted fetus was sent to Philadelphia’s Wistar Institute, where vaccine pioneer Stanley Plotkin isolated the rubella virus from kidney tissue. He developed the vaccine that is given today by growing the virus in an experimental cell line made from the lungs of an uninfected fetus aborted in Sweden.
  • The varicella (chicken pox) vaccine, the hepatitis A vaccine, the original version of the shingles vaccine, and one preparation of the rabies vaccine are all made by growing the viruses in fetal embryo fibroblast cells, according to the vaccine education center of Children’s Hospital of Philadelphia. The fibroblast cells — which hold connective tissue such as skin together — were first obtained from two pregnancies that women chose to end in the early 1960s. Because fetal cells can grow almost indefinitely, “these same cells obtained from the early 1960s have continued to grow in the laboratory and are used to make vaccines today. No further sources of fetal cells are needed to make these vaccines,” CHOP explains.
  • Experts at Massachusetts Institute of Technology and other centers use fetal tissue to implant the human immune system into mice as a way to study diseases without employing people as test subjects. The scientists add tumors to study the immune system’s response, then test cancer treatments on the mice.
  • Researchers at the University of California, San Diego have used fetal tissue and cells to study Alzheimer’s disease and spinal cord injury.
  • Researchers also use fetal tissue to learn about birth defects, as well as the genetic roots of diseases including Down syndrome, sudden infant death syndrome, and eye abnormalities.