The UN said on Thursday 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.
Meanwhile the capacity for dealing with Covid-19 among refugees in rural areas was very limited.
The UNHCR is seeking $455 million (382 million euros) to tackle the additional problems posed in protecting refugees from the effects of the pandemic.
"Now the struggle is for vaccines," Sajjad Malik, UNHCR's resilience and solutions director, told reporters.
"2021 is the beginning but it may very much go into 2022 and beyond because the vaccine is trickling down very slowly into these countries."
There are around 80 million forcibly displaced people worldwide, according to UNHCR's latest statistics.
These include 45.7 million internally displaced people, 26.3 million refugees and 4.2 million asylum seekers.
Despite early fears that refugee camps would prove ideal breeding grounds for the virus, the situation for refugees tends to mirror that of their host communities, Malik said.
He said the socioeconomic impact for refugees in urban areas was stark, with refugees often working on a daily wage basis having lost their income rapidly when lockdowns kicked in.
"Over a very short period of time, they went into a downward spiral of poverty. That is beginning to tell now," said Malik.
"With no income they could not pay their rents, they could not afford their health care. They could not look after their children.
"That has really created a lot of hardships."
Meanwhile in rural areas, health systems which were already struggling to cope before the pandemic had little capacity for testing, isolating and treating Covid-19 cases.
"Where refugees are hosted in rural areas, it's even more difficult," said Malik.
He said the UNHCR was not seeking preferential treatment for refugees in vaccination campaigns, and welcomed that 106 countries had included refugees in their Covid-19 planning.
"They knew that if they leave a proportion of the community out, the entire community is at risk," he said.
Malik's deputy Marian Schilperoord said around 63 000 refugees were known to have been infected with Covid-19.
However, the true figure would be much higher as, besides unreported cases, some countries do not distinguish refugees in their statistics.
Some 48 percent of child refugees were out of school due to the pandemic - with girls more heavily affected.
"Many of these children, most likely the risk is they will not go back to school as a result of one year of no education," said Malik.
Of the UNHCR's supplementary Covid-19 appeal, some $55 million is earmarked for restoring education for child refugees.