“These farms are often open, rustic, with access to bats which are abundant in the region,” he said. A spillover could have occurred at one of the farms and an infected human could have infected others at the Wuhan market.
There is also the question of where the virus evolved its ability to easily pass from human to human. That could have happened in animals, Dr. Andersen said, meaning it would have sprung forth ready to cause a pandemic. Or it could have circulated in humans in a less efficient form, from the virus’s point of view. Then it evolved its pandemic equipment in humans.
In any case, Dr. Andersen said, although the current pandemic is the war we are now fighting, there is no question that another one could come. This one was no surprise, he pointed out. He said, “We hear that nobody could have predicted a pandemic,” he paused, “except for everyone who works in infectious diseases.”
He admitted, however, that before the current pandemic, his main concern was not the coronavirus family. “If I had to make a guess before,” he said, “I would have said flu.”
The best defenses for the future, Dr. Andersen said, would be broadly effective vaccines, like a universal flu vaccine and a vaccine against SARS-like coronaviruses.
Surveillance of animal sources and reaching an understanding of how viruses evolve is essential, but, he said, would not prevent the next pandemic.
As to finding the animal that was the intermediate host, it may happen. But without viral genetic material from the very first human cases or from animals with highly similar viruses, including animals that might have been present at the Wuhan seafood market, that search is very difficult.