MONTREAL -- The Catholic archbishop of Montreal has advised followers to ignore a public letter from a national bishops' group which encouraged Canadians to opt for certain vaccines over others on religious concerns. 

“The Catholic Church in Montreal considers vaccination, especially in the context of the current pandemic, to be an act of charity,” wrote Montreal Archbishop Christian Lepine on Thursday.

“Any authorized vaccine may be used in good conscience by believers.”

The Archbishop’s letter comes days after the Canadian Conference of Catholic Bishops (CCCB) issued a public notice encouraging followers to choose the Pfizer and Moderna vaccines over the newly approved Johnson & Johnson and AstraZeneca options.

What’s the difference? The CCCB claimed the two newly approved vaccines may use human cell lines from aborted fetuses in research and production.

If the choice is available, the CCCB wrote that “the vaccine with the least connection to abortion-derived cell lines should always be preferred and chosen when possible.”

CTV News reached out to AstraZeneca and Johnson & Johnson to clarify how their vaccines were created. Johnson and Johnson responded, writing that fetal tissue is not an ingredient in their vaccine.

“Our vaccine contains no fetal tissue whatsoever,” wrote the company.

“We employ a technology platform using cells that were engineered and grown in labs from a single cell more than 30 years ago into a fully engineered cell line.”

'A VERY POOR USE OF THEIR MORAL AUTHORITY': LAWMAKERS 

Several National Assembly members also denounced the instructions from the CCCB this week.

On Wednesday, Health Minister Christian Dubé “vigorously” denounced the CCCB's letter, encouraging people of all faiths to follow the advice of health experts.

The day after, Liberal leader Dominique Anglade said “science is science,” calling the bishops’ words “irresponsible.” Quebec Solidaire spokesperson Gabriel Nadeau-Dubois called CCCB's statement “regrettable.”

“The bishops have failed in their moral responsibility,” said Nadeau-Dubois. “They have made a very poor use of their moral authority.”

“We’re in a pandemic. We need every dose of vaccine,” said Parti Quebecois leader Paul St-Pierre Plamondon. “All vaccines that are authorized are safe and must be used. It's as simple as that.”

-- With files from the Canadian Press.