The United States Conference of Catholic Bishops has asked American Catholics to avoid using Johnson & Johnsons new COVID-19 vaccine if possible because researchers used stem cells distantly linked to two abortions decades ago.

Two top USCCB leaders Bishop Kevin C. Rhoades of Indianas Fort Wayne-South Bend diocese and Archbishop Joseph F. Naumann of Kansas City in Kansas shared the U.S. Catholic hierarchys views on the first one-shot preventative vaccine against the coronavirus in a statement released on Tuesday .

Rhoades and Naumann said their criticism of the Johnson & Johnson vaccine stems from the fact that the company used cell lines linked to aborted fetuses to help manufacture its vaccines and not just for testing, as is the case with the Pfizer and Moderna vaccines.

If one can choose among equally safe and effective COVID-19 vaccines, the vaccine with the least connection to abortion-derived cell lines should be chosen, Rhoades and Naumann wrote. Therefore, if one has the ability to choose a vaccine, Pfizer or Modernas vaccines should be chosen over Johnson & Johnsons.

Rhoades leads the bishops committee on doctrine, while Naumann is in charge of its committee on pro-life activities.

The bishops statement echoes a missive from the Archdiocese of New Orleans released on Friday in which the archdiocese called J&Js vaccine morally compromised.

We advise that if the Moderna or Pfizer vaccine is available, Catholics should choose to receive either of those vaccines rather than to receive the new Johnson & Johnson vaccine because of its extensive use of abortion-derived cell lines, the archdiocese wrote in its statement .

The bishops declaration could affect vaccine distribution since many churches serve as vaccination centers.

Moderna and Pfizer, the makers of two previously approved COVID-19 vaccines, reportedly used cloned stem cells for testing their vaccines.

The Washington Post noted that the Vatican has already approved the use of vaccines that have used cell lines from aborted fetuses in their research and production process and called them morally acceptable.

Anti-abortion Catholic groups have previously taken issue with drug companies that utilize human cell lines from aborted fetuses, The Hill noted .

Johnson & Johnson said in a statement emailed to HuffPost on Tuesday that there is no fetal tissue in the vaccine, which uses an engineered cell-line system that enables the rapid production of new vaccines.