BRASILIA -- Pfizer Inc plans to seek Brazil's authorization to use its COVID-19 vaccine in children aged 5 to 11 years, the country's health regulator Anvisa said on Tuesday after a meeting with the U.S. company.

Pfizer representatives met with Anvisa to present technical data ahead of a formal submission of its request, the regulator said in a statement.

The dose for children aged 5 to 11 years will be lower than the dose for children over the age of 12 due to a new formula developed by the company, Anvisa said.

Pfizer's Comirnaty vaccine, developed in partnership with BioNTech, has been registered in Brazil since February and is the only shot authorized in Brazil for use on children of 12 years and up.

No other developer has applied to use its vaccine on people younger than 18 years.

The U.S. Centers for Disease Control and Prevention last week backed broad use of Pfizer's vaccine in children ages 5 to 11 in the United States.

Almost 610,000 Brazilians have died from COVID-19, according to health ministry data, in the world's third worst outbreak outside the United States and India and its second-deadliest.

Pfizer and BioNTech on Tuesday again requested the U.S. Food and Drug Administration (FDA) to authorize booster doses of their vaccine in all adults. Currently, the booster is authorized for people aged 65 and above, and other individuals at high risk of being infected on their jobs. 

A panel of advisers to the FDA in September rejected Pfizer's request to use the booster for all individuals aged 16 and above, saying more safety data was needed, especially concerning the risk of heart inflammation in younger people.