Sharing COVID-19 vaccines has been a major subject of discussion at this year's United Nations General Assembly meeting in New York.
South Africa's President Cyril Ramaphosa, Chad's President Mahamat Idriss Deby and Uganda's President Yoweri Museveni were among those who spoke on Thursday.
Most of Thursday's speakers were leaders from African nations.
Their countries are not able to get enough vaccines to protect their people.
Ramaphosa said that it is "an indictment on humanity" that more than 82 percent of the world's COVID-19 vaccines are in the hands of rich countries.
He said less than one percent have gone to poor countries.
He added, "unless we address this as a matter of urgency, the pandemic will last much longer" as new forms of the virus appear.
The struggle to contain the coronavirus also has been a big issue in speeches given at the U.N. meeting.
In a statement to the U.N., Mokgweetsi Masisi, the President of Botswana said: "Botswana shares the frustration by many and strongly supports the call for the vaccines to be treated as a global public good."
On Wednesday, American President Joe Biden announced that the U.S. would buy 1 billion of Pfizer's COVID-19 shots to share with the world.
That was two times the amount of his earlier promise.
He also said he supported a goal of vaccinating 70 percent of the world's population within the next year.
Some countries have had vaccines widely available to their populations for months.
But other countries have struggled to get supplies.
The African Centers for Disease Control and Prevention reports that four percent of the population is fully vaccinated.
Ramaphosa took part in a meeting Wednesday that was called by Biden to talk about increasing efforts to vaccinate people all over the world.
At that meeting, Biden announced the U.S. deal to buy an additional 500 million doses of the Pfizer COVID-19 vaccine to send to other countries.
"Of the around 6 billion vaccine doses administered worldwide, only two percent of these have been administered in Africa, a continent of more than 1.2 billion people," Ramaphosa said. "This is unjust and immoral."
Because of the coronavirus pandemic, a number of world leaders made video presentations instead of traveling to New York to speak in person.
About half of Thursday's speeches were by video.
Speaking on video from Havana, Cuban President Miguel Díaz-Canel denounced the U.S. embargo against Cuba.
He said it has been made worse during the COVID-19 pandemic.
Speaking at the U.N., Panama's President Laurentino Cortizo said his country has vaccinated more than half of its population.
"Thanks to this, we are only weeks away from reaching herd immunity," he said.
Cortizo asked for the support of the international community to deal with the large number of migrants passing through his nation.
Many of the migrants are from Africa and the Caribbean islands.
Cortizo said, "This is everyone's responsibility."
I'm Jill Robbins.
1. in the hands of sb. 受某人照料；受某人控制
The matter is now in the hands of my lawyer.
2. herd immunity 群体免疫
But herd immunity works only when nearly the whole herd joins in．