ROME — From the opening moments of the Group of 20 summit on Saturday, the leaders of the world’s largest economies needed to ship a powerful message about ending the coronavirus pandemic: Throughout an unconventional group {photograph}, they had been joined on the dais by medical doctors in white coats and first responders from the Italian Purple Cross.

In his remarks opening the assembly — the primary gathering in particular person for the group because the pandemic struck — Prime Minister Mario Draghi of Italy pointed to the stark disparity in entry to vaccines between richer and poorer nations.

“Going it alone is just not an choice,” stated Mr. Draghi, whose nation is internet hosting the summit. Now, he added, the world may “lastly have a look at the longer term with nice — or with some — optimism.”

However because the leaders gathered to debate plans to guard in opposition to future pandemics, well being consultants and activists expressed considerations that the world’s richest nations had been nonetheless not doing sufficient to assist individuals in poor nations survive the present one.

Advisers stated President Biden, who has promised to make the US an “arsenal of vaccines,” wouldn’t announce concrete plans associated to closing the hole between wealthy and poor nations on vaccination charges. He would as an alternative be pushing different leaders to discover debt reduction and emergency financing for poor nations whose economies have been battered by the pandemic.

The president got here into the summit focused on other issues, together with fixing world provide chains, urging investments to curb local weather change, and assembly with the leaders of France, Britain and Germany to debate methods to return to a 2015 nuclear accord with Iran that the Trump administration scuttled.

On Saturday, Mr. Biden and different world leaders endorsed a landmark global agreement that seeks to dam massive companies from shifting income and jobs throughout borders to keep away from taxes — a win for the president, whose administration pushed laborious to hold the deal over the end line.

The leaders had been set to formally again the accord in a communiqué to be launched on Sunday, an administration official stated.

However well being consultants and influential advocates, together with Pope Francis, have urged Mr. Biden throughout his journey to remain centered on closing the vaccine hole for poor nations, who’re notably weak to the virus and its variants.

Whereas rich nations are providing individuals third vaccine doses and more and more inoculating youngsters, poor nations have administered an estimated 4 doses per 100 individuals, in response to the World Well being Group.

Jake Sullivan, the president’s nationwide safety adviser, advised reporters on Air Drive One en path to Rome that “the primary thrust of the trouble on Covid-19 just isn’t really touring via the G20.” He stated {that a} virtual summit that Mr. Biden convened in September had set “extra formidable targets” for nations to pledge to share doses of the vaccine.

Though Secretary of State Antony J. Blinken is scheduled to host a gathering of dozens of nations and nongovernmental organizations this 12 months to safe commitments on vaccine sharing, Mr. Sullivan stated the main focus for the Group of 20 was on the longer term.

Mr. Biden stated in June that the US would purchase 500 million Pfizer-BioNTech coronavirus vaccine doses for poorer nations. He adopted up in September by asserting an extra 500 million Pfizer doses, together with the promise of an extra $750 million for vaccine distribution, roughly half of it via a nonprofit concerned in world vaccinations.

Only about 300 million of these doses are anticipated to be shipped this 12 months, a quantity that consultants say falls in need of the quantity wanted for significant safety in opposition to the virus.

“You actually have a failure of developed nations’ management post-Covid,” stated Célia Belin, a visiting overseas coverage fellow within the Heart on the US and Europe on the Brookings Establishment. “That is going to have penalties.”

Certainly, providing vaccine doses to creating nations is greater than an altruistic gesture on the a part of rich nations. The extra the virus continues to flow into globally, the extra probably it’s to proceed producing deadly variants, making it more durable to finish the pandemic and rendering weak wealthy and poor alike.

Since arriving in Rome, Mr. Biden has already heard a private attraction to do extra: Throughout a meeting at the Vatican on Friday, Pope Francis pushed the president on the problem, a senior official stated afterward.

And in an open letter to the Group of 20, the pinnacle of the World Well being Group, Dr. Tedros Adhanom Ghebreyesus, urged the leaders of the world’s largest economies to “to assist stem the pandemic by increasing entry to vaccines and different instruments for the individuals and locations the place these are in shortest provide.”

Because the summit acquired underway, it’s also drew a mélange of protesters who raised safety considerations — laid-off manufacturing facility employees, local weather activists, anti-globalization campaigners, unions, feminist teams, Communists and a few vaccine skeptics.

“There will likely be many people,” stated Gino Orsini, a consultant for the Si Cobas union, one of many organizers of an illustration deliberate for Saturday to coincide with the gathering.

This 12 months is the twentieth anniversary of the Group of 8 summit that Italy hosted in the northern city of Genoa that was marred by rioting. It’s also a second of rigidity between the authorities and opponents of the Italian authorities’s coronavirus vaccination necessities, which have resulted in violent clashes.

“The extent of consideration is most,” stated Giovanni Borrelli, an area authorities official, including that 5,500 further legislation enforcement officers had been being deployed this weekend.

Emma Bubola contributed reporting.