The Covax scheme for ensuring Covid-19 vaccines reach poorer countries said Wednesday it needed $5.2 billion within the next three months to fund jabs for the world in 2022.
Covax reached the milestone of shipping its billionth vaccine dose at the weekend, after a surge in deliveries to countries in November and December, but hopes to ramp up the flow of vaccines this year.
"In 2022, we can help break Covid by adapting our support to ensure doses are used rapidly, get into arms safely, are responsive to country preferences and coverage targets," said Gavi vaccine alliance chief Seth Berkley.
"This will help the world to reduce pandemic risks and uncertainties."
Gavi, along with the World Health Organization (WHO), is one of the co-leaders of the Covax scheme.
Covax wants $3.7 billion (3.26 billion euros) to fund a pool of 600 million doses, to ensure a reliable supply to the poorest countries, and cover eventual variables such as boosters or new variant vaccines.
A further $1 billion would go towards supporting readiness and delivery in poorer nations, and $545 million to cover the costs for rolling out donated doses, such as syringes, transportation and insurance.
The appeal has received $192 million so far from donors.
Berkley expects the next billion doses to take four to five months to deliver, rather than a year for the first billion.
Covax says it has enough confirmed supplies to vaccinate around 45 percent of the population in the 92 countries that receive donor-funded doses.
However, up to 25 of those nations are lagging behind in installing the capacity to get doses from airports into arms.
Covax reckons that it could save more than a million lives in 2022, and halve the economic cost of the pandemic in some countries, with a rapid roll-out.
WHO chief Tedros Adhanom Ghebreyesus said that while nearly 10 billion doses have been administered so far, approaching half the world's population is completely unvaccinated.
He said the imbalance had led to new variants such as Omicron emerging, and "the next one could well be worse".
"In 2022 we can end the acute phase of the pandemic or prolong it. World leaders have a choice."