As COVID-19 rips through China, other countries and the World Health Organization are calling on its government to share more comprehensive data on the outbreak. Some even say many of the numbers it’s reporting are meaningless.

Without basic data like the number of deaths, infections and severe cases, governments elsewhere have instituted virus testing requirements for travelers from China. Beijing has said the measures aren’t science-based and threatened countermeasures.

Of greatest concern is whether new variants will emerge from the mass infection unfolding in China and spread to other countries. The delta and omicron variants developed in places that also had large outbreaks, which can be a breeding ground for new variants.

Here’s a look at what’s going on with China’s COVID-19 data:

WHAT IS CHINA SHARING AND NOT SHARING?

Chinese health authorities publish a daily count of new cases, severe cases and deaths, but those numbers include only officially confirmed cases and use a very narrow definition of COVID-related deaths.

China is most certainly doing their own sampling studies but just not sharing them, said Ray Yip, who founded the U.S. Centers for Disease Control office in China.