Pfizer and its partner BioNTech will apply today for emergency authorisation in the US for their Covid-19 vaccine.
It will be the job of the US Food and Drug Administration FDA to decide if the vaccine is safe to roll out.
It is not clear how long the FDA will take to study the data. However, the US government expects to approve the vaccine in the first half of December.
Data from an advanced trial showed the vaccine protects 94% of adults over 65.
The trial involved 41,000 people worldwide. Half were given the vaccine, and half a placebo.
The two companies said if FDA authorisation does come in the first half of next month, Pfizer and BioNTech will “be ready to distribute the vaccine candidate within hours”.