He also explained that the spike protein itself is not contaminated with fetal cells, as the spike protein produced by the vaccine comes directly from the synthetic RNA injected, and is "100% newly derived and pure."
Lanciotti also noted that there exists a knowledge base that was generated years ago- likely decades ago- about the basic biology of coronaviruses, which Moderna, a ten-year-old company, likely did not create themselves.
Moderna recently announced that a trial of its vaccine demonstrated it to be 94.5% effective. The trial involved 30,000 people, half of whom were given two doses of the vaccine, and half of whom received a placebo.
In an internal memo dated Nov. 23, Bishop Kevin Rhoades, who chairs the bishops' committee on doctrine, and Archbishop Joseph Naumann, the head of the committee on pro-life activities, wrote to the bishops of the United States that the two RNA vaccine candidates appear to be ethically sound.
"Neither the Pfizer nor the Moderna vaccine involved the use of cell lines that originated in fetal tissue taken from the body of an aborted baby at any level of design, development, or production," the bishops wrote.
"They are not completely free from any connection to abortion, however, as both Pfizer and Moderna made use of a tainted cell line for one of the confirmatory lab tests of their products," the bishops wrote, referring to the HEK-293T cell line.
"There is thus a connection [to fetal tissue], but it is relatively remote," the bishops concluded.
The Vatican has said that researchers have a duty to avoid using cell lines derived from aborted children in vaccine production, and have an obligation to "denounce and reject publicly the original immoral act [of abortion]."
The Church has allowed the use of vaccines produced in fetal cells if no alternative exists, while stressing the importance of protesting the vaccine's production and encouraging "vigorous efforts to promote the creation of alternatives."
The Pontifical Academy for Life, in a Nov. 22 statement posted to Twitter, said based on its own 2005 and 2017 guidance on the origin of vaccines, the academy has found "nothing morally prohibitive with the vaccines developed" by Moderna or Pfizer.
The Charlotte Lozier Institute, research arm of the pro-life Susan B. Anthony List, has listed the Moderna vaccine among the "ethically uncontroversial CoV-19 vaccine programs."
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However, Dr. Stacy Transancos, a chemist, argued in a Nov. 20 National Catholic Register op-ed that listing a vaccine which has even a remote connection to aborted tissue as "ethically uncontroversial" could undermine the Catholic fight for ethical medicines.
"Instead of assigning this vaccine to a category that suggests no more caution is needed, I think it is better to slow down and look at the big picture...We need to speak up loudly with clarity and courage about the ethics and insist upon an ethical option. It could redirect this entire issue towards the good," she wrote in her op-ed.
For his part, Lanciotti said that while all the COVID-19 vaccines remain in the testing phases, it appears that two of the three leading candidates are at least produced in an ethical manner free from the use of aborted fetal cells- which is more than can be said for some common vaccines such as MMR, polio, and chickenpox.
"We as Catholics should actually be very pleased that the two leading COVID vaccine candidates are both RNA vaccines with no ethical concerns," he said.
"The third leading candidate, the AstraZeneca vaccine, is in fact a modified virus that is produced in HEK-293 cells. Therefore, that vaccine clearly has ethical problems and should be rejected by Catholics."
Jonah McKeown is a staff writer and podcast producer for Catholic News Agency. He holds a Master’s Degree from the University of Missouri School of Journalism and has worked as a writer, as a producer for public radio, and as a videographer. He is based in St. Louis.