(Corrects day to Tuesday instead of Thursday)

BRASILIA, June 8 (Reuters) - Brazil will receive a first batch of 3 million doses of the single-shot Johnson & Johnson vaccine against COVID-19 in the next few days, Health Minister Marcelo Queiroga said on Tuesday.

Queiroga said export of the vaccines, developed by J&J's Janssen subsidiary, from the United States still requires authorization by the U.S. Food and Drug Administration.

"Of course, if the FDA's decision is delayed, these 3 million doses may no longer be useful for us, due to the short time," he said testifying before a Senate commission of inquiry into the Brazilian governments handling of the pandemic.

This batch of vaccines expire on June 27. Queiroga said they would have to be administered "very fast" in Brazil's national immunization program before they expire.

Brazil signed an agreement with Janssen to receive 38 million doses for delivery in the last quarter of this year, so the first batch is arriving earlier than expected, Queiroga said.

The government is being investigated by the Senate commission for delays in securing timely vaccines, which politicians blame on far-right President Jair Bolsonaro's anti-vaccine view.

Brazil has been hit by the second-deadliest COVID-19 outbreak outside of the United States and is behind most countries in vaccinating its population of 210 million.

So far only 14.5% have been fully vaccinated with two doses mainly of CoronaVac, made by China's Sinovac Biotech Ltd , and the vaccines developed by AstraZeneca and Pfizer Inc.

Brazil has now registered 17,037,129 cases of coronavirus since the pandemic began, in the world's third worst outbreak outside the United States and India, and 476,792 people have died of COVID-10, according to ministry data. (Reporting by Ricardo Brito; writing by Anthony Boadle; Editing by Cynthia Osterman)