Biden never came out against Trump's decision to restrict travel from China. Biden was slow in staking a position on the matter, but he supported it.
On January 31, Trump issued an executive order blocking entry to the U.S. from anyone who has been in China in the last 14 days. On February 2, 2020, Biden tweeted, "We are in the midst of a crisis with the coronavirus. We need to lead the way with science — not Donald Trump's record of hysteria, xenophobia, and fear-mongering. He is the worst possible person to lead our country through a global health emergency."
Later, while addressing Biden on U.S. deaths from COVID-19, Trump said, “If you were here, it wouldn’t be 200,000 people, it would be 2 million people. You didn’t want me to ban China, which was heavily infected.... If we would have listened to you, the country would have been left wide open.”
Biden never came out against Trump’s decision to restrict travel from China. Biden was slow in staking a position on the matter but when he did, he supported the restrictions. Biden never counseled leaving the country “wide open” in the face of the pandemic.
Therefore, the claim is misleading.