A mix-up ruined 15 million doses of Johnson & Johnson’s COVID-19 vaccine

So far, the U.S. Food & Drug Administration has approved three COVID-19 vaccines for use in the United States: one from Moderna, one from Pfizer and one from Johnson & Johnson. And up to 15 million doses of the Johnson & Johnson vaccine have been ruined because of an error at a manufacturing plant in Baltimore, according to the New York Times.

Times reporters Sharon LaFraniere and Noah Weiland explain, "Workers at a plant in Baltimore manufacturing two coronavirus vaccines accidentally conflated the ingredients several weeks ago, contaminating up to 15 million doses of Johnson & Johnson's vaccine and forcing regulators to delay authorization of the plant's production lines. The plant is run by Emergent BioSolutions, a manufacturing partner to both Johnson & Johnson and AstraZeneca, the British-Swedish company whose vaccine has yet to be authorized for use in the United States."

Federal officials, the Times reporters note, have attributed the mistake to human error — not something done on purpose.

President Joe Biden has stressed that he wants to see as many U.S. residents as possible vaccinated for COVID-19 in the weeks ahead.

While the Moderna and Pfizer vaccines require two shots, the Johnson & Johnson vaccine only requires one.