With more than 400,000 deaths – the world’s second-highest toll of the pandemic – Brazil is trying to speed up its slow vaccination programme.
The government of Jair Bolsonaro is accused by critics of failing to buy and roll out doses early enough.
The BBC has followed Brazilian healthcare workers delivering vaccines to one of the most isolated parts of a vast country.
Correspondent: Mark Lowen
Camera: Peter Murtaugh
Producer: Jessica Cruz