Banning it would require switching to single-dose vials for vaccines, which would cost far more and require new networks of cold storage facilities and additional capacity for waste disposal, the authors of the articles said.

“The result would be millions of people, predominantly in low- and middle-income countries, with significantly restricted access to lifesaving vaccines for many years,” they wrote.

In the United States, thimerosal has not been used in children’s vaccines since the early 2000s after the Food and Drug Administration and public health groups came under pressure from advocacy groups that believed there was an association between the compound and autism in children.

At the time, few, if any, studies had evaluated the compound’s safety, so the American Academy of Pediatrics called for its elimination in children’s vaccines, a recommendation that the authors argued was made under the principle of “do no harm.”

Since then, however, there has been a lot of research, and the evidence is overwhelming that thimerosal is not harmful, the authors said. Louis Z. Cooper, a former president of the academy and one of the authors, said that if the members had known then what they know now, they never would have recommended against using it. “Science clearly documented that we can’t find hazards from thimerosal in vaccines,” he said. “The preservative plays a critical role in distribution of vaccine to the global community. It was a no-brainer what our position needed to be.”