NEW YORK -- US fears that this week's annual world leader jamboree at the United Nations could spark a super spreader event that will highlight the stark inequality of global access to Covid-19 vaccines, CNN reported.

Scores of presidents, prime ministers and foreign ministers are set to ignore an American suggestion to stay home and address the UN General Assembly virtually and will converge on New York City in person this week.

The possibility that the visiting delegations might themselves pose a health threat will be an important reminder that while nations like the United States and major European powers have pushed ahead with vaccinating tens of millions of their people, many smaller, poorer nations, which lack pharmaceutical industries, have not been able to secure or make their own vaccines.

The World Health Organization said last week that more than 5.7 billion vaccine doses have been administered globally, but 73 percent of those doses have been administered in just 10 countries.

That reality represents the biggest potential stumbling block to ending the pandemic -- and preventing even more infectious strains of the coronavirus like the Delta variant from building resistance to existing vaccines.

It will also underscore the world's failure so far to come up with a unified response to the worst public health crisis in 100 years, which will be at the center of countless speeches by world leaders in the coming two weeks.

While the social side of the UN General Assembly event and bilateral meetings have been pared back, it's possible that an influx of visitors, many from nations subject to US travel restrictions, could create classic conditions to spread infections and foster global transmission. Although the UN headquarters property is designated as international territory, the delegations will be hosted in a city that now requires proof of vaccination to enter indoor venues like restaurants and gyms.

"We are concerned about the UN event being a super-spreader event," Linda Thomas-Greenfield, the permanent US representative to the UN, said Friday. "We need to take all measures to ensure that it does not become a super-spreader event."

All travelers entering the US will have to show proof of a negative Covid-19 test. But the fact that vaccines are so scarce across much of the world raises the possibility that many delegations will be unprotected.

Thomas-Greenfield called on all nations to ensure that "their actions do not lead to jeopardizing the health and safety of the people of New York, of all of the participants here at the United Nations, and that they don't take COVID back to their home countries."

Given that this is the UN, high-stakes diplomatic jousts have already erupted with some leaders and nations manipulating the politics of the pandemic on display at UNGA to further political and nationalistic goals back home.

Jair Bolsonaro, who as President of Brazil will fulfill the tradition of delivering the first speech at the meeting, is already promising to flout the world body's honor system that asks all entrants to the UN chamber to be vaccinated.

"Why do you take a vaccine? To have antibodies, right? My antibodies rate is really high. I can show you the document," Bolsonaro, who has consistently mocked public health guidelines and himself survived Covid-19, said last week.

Another US antagonist, Russia, has also tried to twist the knife. After its UN ambassador complained about the vaccine requirement, citing unfairness for people with medical conditions or prejudice against vaccines -- like Russia's Sputnik dose, which is not approved by the US Centers of Disease Control and Prevention -- New York City Mayor Bill de Blasio lashed out at Moscow.

"If the Russian ambassador is against it, I'm for it. I have no words for Vladimir Putin and everything else that's come out of Russia," de Blasio said. "If their vaccine isn't good enough then they should go and use one of the other vaccines. That's what we're making available." The city is offering Covid-19 vaccination at the UN headquarters for those who want it.

Given the current controversy over vaccine mandates in the US, Joe Biden might wish for a diversion from the politics of Covid-19 at UNGA, where he will have his first chance as President to lay out his core foreign policy principles in the UN chamber before a global audience. His decision to attend the event, after his administration suggested other nations might give it a pass for health reasons, is in itself a nod to the reality that after months of lockdowns, many leaders are missing the chance to strut the global stage.

The split on vaccines

The US first suggested that world leaders "should consider" giving their speeches virtually in a diplomatic note in August sent by Thomas-Greenfield. She also said that the CDC recommended mandatory mask use in UN headquarters, proof of negative status for Covid-19 to get into the building and, if possible, proof of vaccination.

"The United States needs to make clear our call, as the Host Country, for all UN- hosted meetings and side events, beyond the General Debate, to be fully virtual," Thomas-Greenfield wrote. The ambassador plans to get a Covid-19 test on Monday at the testing and vaccination van that the US has set up outside UN headquarters for the delegations.

Seventy-two heads of state and 30 heads of government are expected to attend the UNGA in person, according to the latest UN list of attendees last week. British Prime Minister Boris Johnson, who is working to coordinate the UN climate summit in Glasgow, Scotland, in November will attend. But French President Emmanuel Macron, Chinese President Xi Jinping and Putin are not expected to travel to New York. Neither is Iran's new President Ebrahim Raisi, who is expected to deliver a virtual address.

The politics of the pandemic are set to dominate the speeches of world leaders over the next few weeks in the vast General Assembly Hall.

Jeff Zients, White House coronavirus response coordinator, stressed last week that the US has purchased 500 million doses of Covid-19 vaccinations from Pfizer to donate to countries "that are most in need."

Biden is expected to use his address to the UNGA on Tuesday to urge wealthier nations to do more to help less well-off countries vaccinate their populations. The White House insists that it is possible for the US to offer booster shots to its people while still helping the rest of the world. But the statistics related to global vaccinations make a damning case.

According to CNN research, at least 217 countries and territories have administered more than 5 billion doses of a Covid-19 vaccine. -- SG/CNN