Currently, there is no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection, the World Health Organisation (WHO) said in a statement.
The international health watchdog also warned against the use of so-called "immunity passports" or "risk-free certificates" after COVID-19 as they may increase the risk of spreading the infection.
Last week, Chile said it would issue the world's first "immunity passports" to people who have recovered from the coronavirus and have developed antibodies to the infection. According to the country's authorities, such passports will allow people to resume working.
As of 25 April, the number of confirmed COVID-19 cases globally has exceeded 2.6 million, with more than 184,000 fatalities, the WHO says.