Bahrain has launched a digital Covid-19 vaccine passport, one of the first countries to do so, the Gulf state's media office said on Wednesday.

Governments and developers around the world are exploring how certificates and passports could help to reopen economies by identifying those protected against COVID-19.

Bahrain's 'BeAware' app displays a green shield alongside an official certificate detailing the person's name, date of birth, nationality and which vaccine was received.

Users must have received two doses of a vaccine, separated by 21 days, and then wait for two weeks for antibodies to develop, the statement said.

"Authorities can verify its validity by scanning a QR code linking to the national vaccine register," it said.

Denmark has said it would launch an initial version of a coronavirus vaccination passport by the end of February.

Sweden also plans to launch a vaccine passport by summer, assuming there is an international standard in place for the document by then, the government said two weeks ago.

Bahrain, a small island state with a population of around 1.5 million, offers citizens and residents free of charge the Pfizer/BioNTech vaccine, one manufactured by Chinese state-backed pharmaceutical giant Sinopharm, the Oxford-AstraZeneca Covid-19 vaccine and Russia's Sputnik V vaccine.