Top US health officials believe that Pfizer Inc's Covid-19 vaccine could be authorised for children aged 5-11 years old by the end of October, two sources familiar with the situation said on Friday.

The timeline is based on the expectation that Pfizer, which developed the shot with Germany's BioNTech, will have enough data from clinical trials to seek emergency use authorisation (EUA) for that age group from the US Food and Drug Administration (FDA) towards the end of this month, the sources said.

They anticipate the FDA could...