GENEVA (AP) — Chinese President Xi Jinping called Monday for greater world cooperation against COVID-19 and said China would send an additional 1 billion doses of vaccine to other countries, while urging other powers to discard a “Cold-War mentality” at a time of rising geopolitical tensions — a veiled swipe at the United States.

The Chinese leader touted his country’s efforts to share vaccines, fight climate change and promote development at home and abroad as he delivered the opening speech of a virtual gathering hosted by the World Economic Forum. The online event is being held in place of its annual January meeting in Davos, Switzerland, because of health concerns linked to the coronavirus pandemic.

The global outbreak that has claimed over 5.5 million lives and upended the world economy was another theme. In a panel session on the virus, Moderna’s CEO said the vaccine maker was working on a single-shot booster for both COVID-19 and the flu, while U.S. infectious diseases expert Dr. Anthony Fauci lamented as “very disturbing” the reluctance of many Americans to follow basic measures like mask-wearing and getting vaccinated.

“This is such a formidable virus,” Fauci said, noting the difficulty in achieving herd immunity against COVID-19 because of the tendency of immunity to fade, even after vaccination. “You make the virus have an advantage when you don’t implement in a unified way all the very well-recognized public health measures, particularly the vaccines.”

Xi, who hasn’t left China since the coronavirus emerged in early 2020, said in his speech that China has exported over 2 billion doses of its COVID-19 vaccines to over 120 countries and international institutions. He announced plans to provide an additional 1 billion — including a donation of 600 million doses to Africa and an extra 150 million to Southeast Asia.

By comparison, managers of the U.N.-backed COVAX program to ship vaccines to developing countries announced over the weekend that it has now delivered 1 billion vaccine doses.

Xi touched on standard themes from previous talks to international audiences, including responding to trading partners’ complaints by promising to open China’s state-dominated economy wider to private and foreign competition.

His comments come as tensions between the United States and China have simmered on topics like Taiwan, intellectual property, trade, human rights and the South China Sea.

“We need to discard Cold War mentality and seek peaceful coexistence and win-win outcomes. Our world today is far from being tranquil,” said Xi, through a translator. “Protectionism and unilateralism can protect no one. They ultimately hurt the interests of others as well as one’s own. Even worse are the practices of hegemony and bullying, which run counter to the tide of history.

“A zero-sum approach that enlarges one’s own gain at the expense of others will not help,” he added. “The right way forward for humanity is peaceful development and win-win cooperation.”

Xi said China “stands ready to work with” other governments on climate but announced no new initiatives and offered no resources. He said it was up to developed countries to provide money and technology.

After Xi spoke, Moderna CEO Stephane Bancel said during a session on the future of COVID-19 that he hoped the U.S.-based company would have a combined vaccine booster ready to test in advanced research in the second quarter, saying a best-case scenario would be if the single shot covering both flu and COVID-19 would be ready for use next year.

“I don’t think it would happen in every country, but we believe it’s possible to happen in some countries next year,” Bancel said.

Moderna has been heavily criticized for prioritizing distribution of its COVID-19 vaccines to rich countries; only a fraction of its supply has gone to poor countries via COVAX. He said the company was aiming to make about 2 to 3 billion doses this year and hopes to have data from a new vaccine tweaked to address the omicron variant in March.

In a panel on technology cooperation, access to broadband internet was raised as an inequality issue and an expensive gap that needs to be filled. Speakers like Verizon Communications CEO Hans Vestberg said transparency around protecting the privacy of people’s data will be crucial, including collaboration between corporations and governments.

The annual Davos gathering usually takes place in person in the Alpine snows of eastern Switzerland, drawing hundreds of business leaders, cultural elites, academics and government leaders. Leaders of countries like Germany, Colombia and Japan were set to address the gathering that runs through Friday.

On tap later Monday were speeches by Indian Prime Minister Narendra Modi and U.N. Secretary-General Antonio Guterres.