Vaccine sharing and reduced trade barriers are vital if the target to inoculate 40 per cent of the world's population can be achieved by the end of 2021, global health leaders say.
The heads of the World Health Organisation, International Monetary Fund, World Bank Group and World Trade Organisation said the lack of vaccines in developing nations makes it easier for new variants of the virus to take hold.

They said the shortfall was creating a “two-track” pandemic, with low-income nations receiving “less than 1 per cent of vaccines administered so far”.
The leaders spoke during a press conference at the WHO on Tuesday as they announced new funding efforts to tackle vaccine inequality around the world.
WHO Director General Tedros Adhanom Ghebreyesus said the funding would "dramatically scale out the production of diagnostics treatments, oxygen, medical equipment and vaccines for equitable distribution."
The attendees – including IMF chief Kristalina Georgieva and WTO Director General Ngozi Okonjo-Iweala – confirmed there would be $50 billion (£35bn) in new grants to help developing countries with their vaccination campaigns.
They suggested a target of vaccinating 40 per cent of the world’s population by the end of this year, rising to 60 per cent by the first half of next year.
They also called for an immediate commitment to send doses abroad, as well as investment in vaccine production to produce an extra 1 billion doses, along with seamless global trade to allow vital vaccine ingredients to cross borders.
The World Bank now has $12 billion in Covid-19 vaccine financing available and will have approved vaccination financing operations in over 50 countries by the end of June, the development lender's president, David Malpass, said at the conference.
Dr Maria Van Kerkhove said the WHO was closely monitoring reports of a coronavirus mutation that was first detected in Vietnam.
The American epidemiologist said the strain appeared to be a mutation of the Indian strain, now called the Delta strain under the WHO's new naming system.
The news comes amid growing concern that the next stage of England’s road map out of lockdown on June 21 could be delayed due to the spread of the Delta strain.
Getting first dose
About 75 per cent of British adults have received their first dose of a Covid-19 vaccine and more than 48 per cent have had both doses.
However, only those over 30 are currently eligible to receive the shot, although some over-18s are being invited to come forward to receive their injections in hotspot areas.
In a letter, more than 100 cross-party British MPs have urged Prime Minister Boris Johnson to export more vaccines to developing countries to prevent new strains from wrecking the UK’s path to normality.
The signatories called for a “one in, one out” policy, with one dose donated for every one purchased.