Pfizer Inc. (PFE) would not give a discount to any developed country for its novel coronavirus (COVID-19) vaccine — over the price it's charging the United States under a contract signed last week — CEO Albert Bourla said at a conference call Tuesday.

What Happened: "All the countries that are developed right now will not receive a lower price for the same volume commitment than the U.S.," Bourla said, as earlier reported by Reuters.

The pharmaceutical company's pre-order deal with the U.S. government prices a single dose of the potential vaccine at $19.5, with the total course of two doses costing $39.

Pfizer could change the prices once the coronavirus outbreak's official status as a pandemic is over, Reuters noted.

The New York-based company began the late-stage clinical trials for its vaccine, co-developed with Germany's BioNTech SE (BNTX), on Monday.

Why It Matters: Rival Moderna Inc. (MRNA) is looking to price its similar vaccine candidate in the range of $50 to $60, according to a report from the Financial Times the same day.

Another vaccine candidate from AstraZeneca plc's (AZN) appears to be priced around $3 to $4 per dose, under its agreements with the governments of the Netherlands, Germany, France, and Italy, according to an analyst note from SVB Leerink's Geoffrey Porges.

Price Action: Pfizer shares closed about 4% higher at $39.02 on Tuesday, and were unchanged in the after-hours session.