It is no secret that thousands of laboratories around the world use cells derived from a fetus that was aborted decades ago to develop vital medicines.But it is a contentious topic in the United States, where conservatives and anti-abortion activists have long deemed the practice unethical.The matter is once more under the spotlight after President Donald Trump was treated for Covid-19 using Regeneron’s antibody treatment. The company used aborted fetal cells as part of its testing process. “It…