Workers unload boxes of the Sinopharm Covid-19 vaccine donated by China at Damascus International Airport in the Syrian capital on April 24, 2021.

Loua Beshara | AFP | Getty Images

The competition between the US and China could heat up on another front: Covid-19 vaccine diplomacy.

China has been a major supplier of Covid vaccines to much of the developing world, an effort some experts said could strengthen Beijing’s global influence and deepen its ties with other nations.

But a health policy and policy expert told CNBC on Thursday that the US is now catching up as the White House lays out plans to donate millions of doses of Covid vaccine overseas and President Joe Biden appears to want to do more.

“We will see China face a more formidable competitor,” Yanzhong Huang, Senior Fellow on Global Health at the Council on Foreign Relations, told CNBC’s Squawk Box Asia.

In recent months, China has been “almost the only major player” sending Covid vaccines to other countries, said Huang, who is also a professor at Seton Hall University’s School of Diplomacy and International Relations.

This is especially true if India has stopped exporting vaccines to prioritize its domestic needs and Russia’s supply abroad remains very limited, he said.

Several reports have indicated that the US is stepping up its efforts to exchange Covid vaccines around the world.

Biden will reportedly announce in a speech at the G-7 summit on Thursday that the US will buy 500 million more doses of the Pfizer BioNTech vaccine to share with COVAX, a global vaccine exchange initiative .

CNBC also reported Wednesday that the government is negotiating with Moderna to secure additional doses of vaccine to supply the world.

Origins of Covid-19

Relations between the US and China got off to a bumpy start under the Biden administration. The two sides have clashed on several issues, including the origins of the coronavirus, which was first discovered in the Chinese city of Wuhan.

Biden said last month he ordered a closer look at the origins of the pandemic, including whether the virus escaped from a Chinese laboratory. In response, China accused the US of a political “guilt game”.

Huang said the issue of the origins of Covid-19 is so politicized that it is likely to fuel further tension between the US and China if additional evidence emerges to the possibility that Covid-19 stems from a laboratory incident.

Without China’s cooperation, such evidence of “smoking weapons” may not be found, Huang said. In the West, however, the theory that the virus came from a laboratory has become an increasingly “credible, if not mainstream,” explanation for the origin of the pandemic, he said.