The world’s most trafficked mammal, pangolins are barred from international trade and are protected domestically in China. But pangolin meat and blood are considered delicacies on the black market, and sales of their scales for use in traditional Chinese medicine remain legal for certain hospitals and pharmacies.

Whatever the source turns out to be, the new ban on wildlife trade comes too late to stanch the spread of this latest coronavirus.

“Now that human-to-human transmission is happening, the ban has no real consequence for this outbreak at all,” said Christian Walzer, executive director of health at the Wildlife Conservation Society.

The government’s ban also lasts only until “the epidemic situation is lifted nationwide,” according to the government’s order. Dr. Walzer and others believe that the ban needs to be permanent if it is to have any effect on reducing the risk of future zoonotic diseases.

“Otherwise, we’ll be having this conversation at regular intervals,” he said.

During the SARS epidemic in 2003, China enacted a narrower wildlife trade ban. Many conservationists and medical professionals, including members of the Chinese Academy of Sciences, hoped it would be permanent, but the trade roared back after the crisis ended.

“Once a disease jumps into humans, all the responses are reactive and the focus is on human health,” said Dr. Alonso Aguirre, a wildlife ecologist at George Mason University.

After the crisis passes, attention turns away from the trade that brought the disease to humans, he added. Scientists have been calling for permanent restrictions for at least three decades.