People who spread misinformation on Covid-19 vaccines are “criminals” and have cost “millions of lives,” Pfizer CEO Albert Bourla said Tuesday.

Speaking with Washington D.C.-based think tank Atlantic Council, Bourla said there is a “very small” group of people that purposefully circulate misinformation on the shots, misleading those who are already hesitant about getting vaccinated.

“Those people are criminals,” he told Atlantic Council CEO Frederick Kempe. “They’re not bad people. They’re criminals because they have literally cost millions of lives.”