An ingredient apparently used in the Johnson & Johnson COVID-19 vaccine has the Diocese of Rockville Centre asking people to avoid getting the one-dose shot.

The diocese says the vaccine is "morally compromised" due to links to cells derived from aborted fetal tissue.

In a strongly worded statement the diocese said, "Abortion is a morally evil act which cannot be voided or reduced in gravity even by the good intention to help others (i.e. as vaccine production)."

While the diocese did not go as far as prohibiting the Johnson & Johnson vaccine — it said, "On moral grounds related to their connection to the evil of abortion, it is recommended that of the alternatives available now or in the very near future, the Pfizer and Moderna vaccines are preferred to the Johnson & Johnson and AstraZeneca vaccines."

The church's statement comes days after the Food & Drug Administration granted emergency-use authorization to Johnson & Johnson's COVID-19 vaccine, which health experts hailed because it requires only one shot and isn't limited by cold-storage requirements.

Johnson & Johnson company officials say its vaccine formula includes no fetal tissue.

Dr. Anthony Fauci, the nation's top infectious disease expert, who was raised Catholic, last week urged Americans to take any of the three coronavirus vaccines now available to them and not delay getting one vaccine over another.

"These are three highly efficacious vaccines. I can tell you I have been fully vaccinated with one that was available. It was the Moderna," says Fauci. "If I were not vaccinated now, and I had a choice of getting J&J vaccine now or waiting for another vaccine, I would take whatever vaccine would be available to me."

The Vatican's position differs from the Diocese of Rockville Centre. Pope Francis has said that people have a moral obligation to get the vaccine.