President Biden said Wednesday he was glad to see Pfizer’s report that a third dose of its COVID-19 vaccine works against the Omicron variant — dashing two weeks of speculation that the mutant might elude the protection of vaccines.

“The expectation is that the existing vaccines protect against Omicron, but if you get the booster, you’re really in good shape,” Biden said as he departed the White House for a trip to Kansas City, Mo. “And so that’s very encouraging news.”

“That’s the lab report,” the president added. “We have more studies going on. But that’s very, very encouraging.”

Pfizer says the COVID-19 variant first detected last month by South African scientists is unlikely to fuel a viral resurgence if people get a third dose of the vaccine.

“Although two doses of the vaccine may still offer protection against severe disease caused by the Omicron strain, it’s clear from these preliminary data that protection is improved with a third dose of our vaccine,” Pfizer CEO Albert Bourla said in a statement.

Pfizer’s vaccine has been used in more than 55 percent of all US inoculations against COVID-19.

Biden didn’t say Wednesday whether he would roll back international travel restrictions in light of the positive news. He has taken heat from African leaders for restricting travel to the US from eight southern African countries following the discovery of the Omicron variant, which scientists initially feared would be more contagious due to its high number of mutations.

White House press secretary Jen Psaki has fended off accusations from African journalists that the travel ban is unscientific, especially as Omicron spreads across the US, Europe and Asia.

Pfizer and its German partner BioNTech said preliminary results of a study show that “[n]eutralization against the Omicron variant after three doses of the Pfizer-BioNTech COVID-19 vaccine was comparable to the neutralization against the wild-type strain observed in sera from individuals who received two doses of the companies’ COVID-19 vaccine.”

Pfizer didn’t offer a percentage for vaccine efficacy against Omicron after each dose. Two doses of the company’s vaccine were about 95 percent effective against transmission of the original COVID-19 strain, suggesting three doses of the vaccine would achieve the same approximate efficacy against Omicron.

White House deputy press secretary Karine Jean-Pierre described the Pfizer announcement as “encouraging news.”

“The news today is an important reminder to get boosted,” she told reporters on board Air Force One. “It increases your protection and offers you protection against Omicron. We need everyone to get vaccinated … That is the whole, the whole goal here, is to get out of this pandemic and make sure that we get ahead of what’s to come.”

The Delta variant of COVID-19, which spread over the summer, was roughly twice as contagious as the original variant of the coronavirus, driving up US infections and impeding the goal of reaching herd immunity through mass vaccination.

Pfizer previously said its vaccine was 88 percent effective against transmission of the Delta variant after two doses. Studies show the vaccine reduces the risk of serious illness and death in people who do become infected.

According to CDC data, 83.5 percent of US adults have had at least one COVID-19 shot, as have 75.7 percent of all Americans five and older. All adults became eligible for booster shots last month, but so far, just 25.9 percent of people 18 and up have gotten one.