Lab leak? Why Congress is split on investigating COVID’s origins.

Both sides say it’s important to get the truth of how the pandemic started. Republicans want Congress to investigate the lab leak theory, which has gained new credence. But Democrats are wary of a politicized process.

A year and a half into a worldwide pandemic that is blamed for the deaths of more than 3 million people, a Chinese lab in Wuhan is under growing scrutiny for a possible connection to the outbreak of COVID-19.

Republican members of Congress, who have raised questions since early 2020 about China’s lack of...