(Reuters) — Johnson & Johnson said on Thursday it has asked U.S. health regulators to authorize its single-dose COVID-19 vaccine for emergency use.

The drugmaker’s application to the U.S. Food and Drug Administration (FDA) follows its Jan. 29 report in which it said the vaccine had a 66% rate of preventing infections in its large global trial.

The Food and Drug Administration is asking its independent advisers to publicly debate all the data behind the single-dose shot before it decides whether to green light a third vaccine option in the U.S. The panel will meet Feb. 26.

J&J’s single-shot vaccine could help boost supply and simplify the U.S. immunization campaign, amid concerns of fresh surges due to the more contagious UK coronavirus variant and the potential of lower vaccine efficacy against the variant that first emerged in South Africa.

Unlike the two currently authorized vaccines from Pfizer Inc/BioNTech SE and Moderna Inc, J&J’s does not require a second shot or need to be shipped frozen.

After the company’s application, regulators will need time to analyze the data and an advisory committee will need to meet. The company’s chief scientific officer said last month J&J was on track to roll out the vaccine in March.

Shares of Johnson & Johnson, Moderna and Pfizer were little changed in after-hours trade.

The United States has an agreement to buy 100 million doses of J&J’s vaccine for $1 billion, and the option of purchasing an additional 200 million doses.

The company has said it has doses ready for delivery upon emergency approval. It aims to deliver 1 billion doses in 2021 with production in the United States, Europe, South Africa and India.

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