The decision from Luís Roberto Barroso challenges a more lenient rule announced by the government of President Jair Bolsonaro, who has opposed mandatory immunization against the virus that can cause COVID-19.
Barroso’s ruling must be reviewed by all 11 judges of the Supreme Court next week.
The federal government announced Tuesday that travelers arriving in Brazil did not have to produce a vaccine passport though they would have to undergo a five-day quarantine.
In ruling on a petition filed by the Network Sustainability party, Barroso said monitoring the quarantines of thousands of travelers would be too difficult and would put Brazilians at risk.
“The threat of promoting anti-vaccine tourism, due to the imprecision of the regulations that require the voucher, represents an imminent risk,” Barroso said in the ruling.
Brazil's president has argued that those backing the use of vaccine passports want to restrict freedoms of the population.
“Where is our freedom? I’d rather die than lose my freedom,” Bolsonaro said Tuesday.
More than 616,000 people have died of COVID-19 in Brazil, the country with second-most deaths from the disease.
The pandemic has waned in recent months and the nation’s seven-day average is approaching 200 deaths a day. But many of Brazil’s major cities, including Rio de Janeiro, have either cancelled or scaled back their New Year’s Eve festivities due to fears of a new spread of the virus.