Trump’s Coronavirus Testing Chief Concedes a Lag in Test Results

“I’m sure there’s an outlier at 12 to 16 days because that happens,” he added, “but that’s very atypical.”

Dr. Giroir’s comments, during a hearing of the House Select Subcommittee on the Coronavirus Crisis, were met with puzzlement by public health experts, who say testing shortages persist. In some places, tests cannot be processed at all because of a lack of reagents — the chemicals needed to detect whether the virus is present — or lab capacity.

And anxious patients around the country paint a far bleaker picture. Shawn Jain, who was tested along with several family members on July 7 in Nashville, waited 16 days for his results after they were processed by Quest Diagnostics. Some of his family members still have not heard back.

“I honestly thought they had lost the test,” said Mr. Jain, who tested negative for the virus. He added, “It made me feel like, well if in the future I do worry I have it, I can’t even rely on something as basic as testing.”

On Friday, the National Institutes of Health announced awards totaling $248.7 million for seven companies to ramp up test production and deliver millions more weekly tests as early as September. The N.I.H. director, Dr. Francis Collins, described the announcement as the “first of more awards to come.” Three of the tests are simple enough to deliver results in 30 minutes or less.

At the hearing, Dr. Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases, said again that a safe and effective coronavirus vaccine would most likely be ready by the end of this year or early next, and cast doubt on efforts by Russia and China.

“I do hope that the Chinese and the Russians are actually testing the vaccine before they’re administering the vaccine to anyone,” Dr. Fauci said.