President Donald Trump said he believed the head of the Centers for Disease Control and Prevention, Dr. Robert Redfield, was “confused” about the timeline for availability of a coronavirus vaccine.

Redfield had told a Senate panel Wednesday that while there may be vaccines in limited supply from November through December, but that it was unlikely the general public would have access to a vaccine until the summer or fall of next year.

“I believe he was confused,” Trump told reporters at the White House on Wednesday. He later added, “I got the impression that he didn’t realize he said what he might have said.”

Redfield also said that wearing a mask may be more effective than a vaccine, another point Trump disagreed on.

Masks are “the most important, powerful public health tool we have” to fight the pandemic, Redfield said. “I might even go so far as to say that this face mask is more guaranteed to protect me against COVID than when I take a COVID vaccine,” noting that vaccines are not 100% percent effective.

“A vaccine is much more effective than the mask,” Trump contradicted during the White House briefing.

He confirmed that he still was confident in Redfield’s abilities and had called him earlier to ask “What’s with the mask?”

“He said I think I answered that question incorrectly. I think maybe he misunderstood it,” Trump said.

Redfield took to Twitter to clarify his comments after the briefing.

“I 100% believe in the importance of vaccines and the importance in particular of a #COVID19 vaccine,” Redfield wrote. “A COVID-19 vaccine is the thing that will get Americans back to normal everyday life. The best defense we currently have against this virus are the important mitigation efforts of wearing a mask, washing your hands, social distancing and being careful about crowds.”