NO ONE yet knows the severity of an outbreak of a novel coronavirus in Wuhan, China, that causes a pneumonia-like illness that has infected at least 555 people and led to at least 17 deaths. But it is not too soon to embrace the lessons of two earlier outbreaks: severe acute respiratory syndrome, or SARS, which began in China in 2002, and the Middle East respiratory syndrome, or MERS, in Saudi Arabia in 2012. Both showed that transparency and early international cooperation are vital to saving lives. The tendency of authoritarian regimes to cover up at times of trouble must be resisted.

China was shaken by the mistakes in handling SARS, which killed 774 people, including 349 in China, and infected more than 8,000 worldwide between November 2002 and July 2003. A subsequent study of China’s response concluded: “A fatal period of hesitation regarding information-sharing and action spawned anxiety, panic, and rumor-mongering across the country.” This time, China’s leadership has attempted to show a different reaction, with one Beijing government agency declaring, “Anyone who deliberately delays and hides the reporting of cases out of his or her own self-interest will be nailed on the pillar of shame for eternity.”

That is the right message, if a bit melodramatic. But the real test will be in execution. Local authorities may fear the consequences if the virus seems to be out of control. They will also be tempted to use China’s considerable censorship machine to suppress the facts. The Post’s Anna Fifield described a case in which a woman with a suspected infection died under circumstances that would suggest the government did not want her family to know she had the coronavirus.

China at first said the new virus did not appear to be spreading from human to human, but then reported that it was. A disease outbreak comes with significant uncertainty, but Beijing must be careful not to complicate the situation by deliberately masking it. China promptly shared the genetic sequence of the new virus with the rest of the world, but the challenges will not end there. Key unknowns are how the virus transmits from person to person, and its lethality, both of which China should help answer in the near future.

As many epidemics — from swine flu to Ebola — have demonstrated in recent years, managing public trust at a time of crisis is just as important as the biomedical aspects of an outbreak. The decision Wednesday to curtail outbound travel from Wuhan, a city of 11 million, is a big gamble. A decision in Monrovia, Liberia, to quarantine an urban neighborhood during the Ebola outbreak of 2014 turned chaotic as people inside the cordon struggled to exit. The study of the SARS response found secrecy created an information gap that hindered the government’s own actions. Today, on the eve of the lunar new year, when some 400 million people are on the move, we hope China’s leaders know better.

Read more: