The Secretariat for Pro-Life Activities of the United States Conference of Catholic Bishops released a document in January 2021, answering key ethical questions about COVID-19 vaccines. In summary:

1. "Neither Pfizer nor Moderna used an abortion-derived cell line in the development or production of the vaccine."
2. "Given that the COVID-19 virus can involve serious health risks, it can be morally acceptable to receive a vaccine that uses abortion-derived cell lines if there are no other available vaccines comparable in safety and efficacy with no connection to abortion."