Newly released text messages from Dr. Anthony Fauci are raising fresh questions about how he responded to changing COVID evidence, according to Dr. Marc Siegel, Fox News senior medical analyst. Siegel said officials were too slow to adjust as information evolved during the pandemic.

The texts came from an initial group of communications taken from Fauci's government issued cellphone. Sens. Ron Johnson, R Wis., and Rand Paul, R Ky., released the messages Monday.

The communications offer a look at private discussions between Fauci and other leading health officials as they confronted developing questions about the coronavirus pandemic. Fauci previously served as the White House chief medical adviser.

In a Monday evening interview, Siegel described Fauci as a "top immunologist" and "top vaccinologist." He added, "And I respect that a lot," while saying he believed Fauci later moved beyond those areas of expertise.

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Siegel questioned whether Fauci showed enough flexibility as scientific evidence changed. "The other issue is flexibility. I have a feeling about Dr. Fauci that he's too dogmatic," he told Fox News Digital.

According to Siegel, Fauci would "stick to some idea he has and [follow] it through regardless of contradictory or changing evidence." Siegel argued that Fauci moved beyond his medical training and knowledge when addressing lockdowns, school closures and masking.

Siegel also criticized the way Fauci appeared to interact with other officials. Regarding the texts, he said, "it looks like he was trying to guide other public officials and leaders from the television camera, and that's not what you should be doing."

COVID vaccination during pregnancy was among the subjects addressed in the newly released messages. Siegel stressed that he remains a strong supporter of vaccines, including mRNA technology.

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"I'm a big fan of the COVID vaccines and of the mRNA COVID vaccines," Siegel said. "I think they're getting a bad rap right now."

Siegel said pregnancy created a complicated risk calculation because COVID itself posed dangers to expectant mothers. Based on the information available early in the pandemic, he said recommending vaccination during pregnancy was reasonable.

However, Siegel said the public discussion should have changed as the virus mutated and vaccines became less protective. He argued that those developments needed to become part of the public debate more quickly.

"As the vaccine changed and the virus mutated, and as the vaccine became less protective, that needed to be entered into the public debate about the vaccine — and Dr. Fauci wasn't fast enough to do that," Siegel said.

Siegel also cited a study that raised questions at the time about a possible connection between a second vaccine dose and early miscarriage. "I don't think that Dr. Fauci and others may have been quick enough to consider that," he said.

At the same time, Siegel said later research has continued to support vaccination during pregnancy. He said "the accumulation of data right now favors the vaccine throughout pregnancy," while questioning whether contradictory evidence received enough consideration when it appeared.

Siegel said medical decisions should remain between patients and their doctors, while emphasizing that the underlying medical data was "not suppressed." He also objected to the government imposing its position when its views could be incorrect or poorly informed.

Another concern, Siegel argued, was that mandates remained in place even as evidence about vaccine effectiveness changed. "I think the problem was that the mandates continued," he said.

"We were too slow to pivot on this vaccine, and that led to a lot of public distrust," Siegel added. Asked whether Fauci's private discussions differed meaningfully from what Americans heard publicly, Siegel said there was "more than I would like."

"There's a difference between public and private discourse here," Siegel said. "There should be none."

As more messages emerge, Siegel said he will examine whether Fauci's guidance changed alongside the available evidence. He asked whether there was an evolution in guidance and thought as additional information became available.

Still, Siegel warned against evaluating pandemic communications without considering what scientists understood at each point. "To be fair to Dr. Fauci, things need to remain in context," he said.

"When did this happen? What was going on at the time? What did we know and what did we not know?" Siegel asked.

He said officials were learning while confronting a virus about which little was initially known. That uncertainty, he argued, made a willingness to change course especially important, with humility preferable to dogma.