But "reality-based skepticism about swine flu" doesn't mean that people would refuse immunization, he said, if an outbreak was a real public danger -- caused by a "highly transmissible agent, likely to be virulent, highly preventable with reliably effective vaccine."
He warned that public health professionals must avoid "falling in love with the most dire forecast and then pushing high-tech precautions against the worst-case scenario."
When that happens, "people have to be excused for wondering whether the officials, the media, and the pharmaceutical companies were in cahoots on swine flu."
But several experts argued that preparing for a worst-case scenario was the responsible thing to do.
Sometimes, "mother nature throws us a break," argued Dr. Howard Markel of the University of Michigan in Ann Arbor.
"We responded to a threat without knowing the future," he said in an email. "A far worse outcome might have occurred if we did not take the threat seriously and H1N1 turned out to be worse than we initially predicted."
The public health response should be compared to the use of seatbelts or auto insurance, according to Dr. Gregory Poland of the Mayor Clinic in Rochester, Minn.
Every day, he said in an email, he puts on his seatbelt before driving. "I don't finish each day and say 'what a waste, I didn't have an accident,'" he said.
"It is -- and remains -- unpredictable as to whether this virus could further mutate or change in a manner such that it could literally turn deadly within weeks," he added. "If this pandemic had been deadly -- and you don't know until you are into it -- and we weren't prepared, the criticism would have been overwhelming."
Moreover, he and others noted, the flu season isn't over yet.
"This argument should be taking place at the end of the flu season in late March, not now," said Dr. Peter Katona of the University of California Los Angeles. "Flu is unpredictable, and this is the heart of the argument."