(Bloomberg) -- Pfizer Inc. will soon submit data to U.S. regulators on a fourth dose of its Covid-19 vaccine, Chief Executive Officer Albert Bourla said.

Bourla said he spent Tuesday morning reviewing new data from various Covid vaccine studies, including one looking at the effects of a fourth dose of the currently available vaccine, as well as a new formulation that will protect against multiple coronavirus variants. 

“They look encouraging,” Bourla said in an interview on Bloomberg Television’s “Balance of Power With David Westin,” noting that Pfizer still needs to collect more information. 

Pandemic concerns are abating as the omicron surge in cases has faded over the past few weeks. Still, the ability of the coronavirus to mutate suggests that more vaccines and boosters will be needed to control future variants as they arise.  

The CEO anticipates that Pfizer will approach the U.S. Food and Drug Administration either this month or in early April with the data on a fourth dose that may help restore immunity, in addition to results from a study of a version that specifically targets the omicron variant. The shots were developed in collaboration with BioNTech SE, based in Germany. 

Pfizer’s studies of both the fourth-dose booster and the omicron-specific shot are still underway, spokeswoman Jerica Pitts said. Once all the data are available, the company will analyze it and share insights with health authorities and regulators, she said. 

Bourla said he’s optimistic about developing a vaccine that would target omicron along with earlier variants, but didn’t provide a timeline for results. Findings from a study of a three-dose regimen of the company’s vaccine for children under the age of 5 are also expected next month, he said. 

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