The World Health Organization on Thursday urged countries to do more to protect health care workers, saying that they are increasingly plagued by anxiety, burnout, illness and death on the front lines of the fight against the coronavirus pandemic.The agency estimates that 115,500 health care workers around the world died of Covid-19 between January 2020 and May 2021, the middle scenario of its broader estimate of 80,000 to 180,000 deaths during that period.Speaking at a W.H.O. briefing on Thursday, Annette Kennedy, the president of the International Council of Nurses, said that the world had entered the pandemic with a shortage of nurses and that the problem was only being worsened by the stresses of the pandemic.“There is another crisis coming down the tracks,” she said, “and that is a shortage of health care workers.”To combat the problem, the W.H.O. called on governments to strengthen their collection of data on Covid infections and deaths among health care workers and to accelerate the vaccination of those workers.On average, two in five health care workers had been fully vaccinated by September, according to W.H.O. data from 119 countries, but that included less than one in 10 of health care workers in Africa and the western Pacific region. By contrast, 80 percent of health care workers in 22 mostly high-income countries had been vaccinated.Ms. Kennedy noted a major problem that women face when working in health care settings: personal protective equipment designed by men. “And yet,” she noted, “90 percent of nurses are women. Seventy percent of all health care workers are women.”W.H.O. leaders also highlighted inequality in the global distribution of vaccines and called on wealthy nations to lead the charge in addressing the issue.The agency’s director general, Dr. Tedros Adhanom Ghebreyesus, said it had been more than 10 months since the first vaccines were approved and that the lack of vaccinations for millions of health workers was “an indictment on the countries and companies that control the global supply of vaccines.”High- and upper-middle-income countries have administered almost half as many booster shots as the total number of doses administered in low-income countries, he said.To meet global vaccination goals, Dr. Tedros said, “the barrier is not production. The barriers are politics and profit.”Gordon Brown, the former British prime minister who is now the W.H.O.’s ambassador for global health financing, said the goal of vaccinating 40 percent of adults around the world by December, which was put forward last month at the Global Covid-19 Summit led by President Biden, had “no chance” of being met without action from wealthy countries.Mr. Brown said 240 million vaccine doses were lying unused in the West, citing figures from Airfinity, a data research agency. He added that the number of unused doses was projected to reach 600 million by the end of December. A shortfall of 500 million doses in the global South could be alleviated by flying vaccine stockpiles to countries in need and by switching delivery contracts. Up to 100 million doses could pass their use-by dates and end up being destroyed, he said.Ahead of the Group of 20 summit that starts in Rome on Saturday, Western leaders should make a plan to transfer vaccines, Mr. Brown said, and other G20 nations could follow suit.