The United Nations has said that vaccinating some of the world's most vulnerable refugees could drag on beyond 2022 due to the slow roll-out of Covid-19 jabs in host countries.

UNHCR, the United Nations Refugee Agency, said many urban refugees were driven into a downward spiral of poverty last year by the coronavirus pandemic.

The UNHCR is seeking $455 million (382 million euros) to tackle the additional problems posed in protecting refugees from the effects of the pandemic, according to an AFP report.

“Now the struggle is for vaccines,” Sajjad Malik, UNHCR's resilience and solutions director, told reporters.