What is a gaffe? Journalist Michael Kinsley offered this helpful definition: It’s when a politician accidentally tells the truth.

By that standard, President Biden may have committed a gaffe on Friday. He was asked about Facebook’s role in discouraging people from vaccinating themselves against COVID-19.

“They’re killing people,” Biden said of the social media giant’s lax control over the use of its platform. “The only pandemic we have in this country is among the unvaccinated.”

Facebook’s hurt feelings were the subject of some blog posts over the weekend, and on Monday, Biden walked his statement back a little. He made clear that he did not believe that Facebook was literally killing some of its customers. Biden said it was the misinformation that the corporation allows to flow through its channels reinforcing false beliefs about the vaccines’ safety that is killing people.

That might have soothed Facebook, but it should not satisfy the rest of us.

A $1 trillion company with 2.8 billion users worldwide, Facebook is too big and too dangerous to escape responsibility for what its users do with the megaphone provided them. Giving a global audience to a conspiracy theorist is like handing a loaded gun to a small child.

Facebook recognizes this, and after it was found to be the platform of choice for political disinformation in the 2016 presidential campaign, it publicized steps it would take to keep the bad actors out.

Most famously, Facebook banished former President Donald Trump, who was found to be the single biggest source of lies about the 2020 election. It also banned right-wing groups, which had been using Facebook to organize efforts to stop counting the 2020 election vote. But vaccine misinformation is still circulating.

Last week, Surgeon General Vivek Murthy called on social media companies to rein in false information that discourages people from getting vaccinated, calling it “an urgent threat to public health.”

Murthy cited a study that found that 67 percent of unvaccinated adults had heard at least one COVID-19 myth and either believed it to be true or were not sure. He cited an analysis of millions of social media posts that found false stories were 70 percent more likely to be shared than true stories. Another study showed that even brief exposure to misinformation made people less likely to want a COVID vaccine.

“Modern technology companies have enabled misinformation to poison our information environment, with little accountability to their users,” Murthy said.

This warning comes at a time when the United States is at a pivot point on the pandemic.

As of Monday, 161 million Americans, just under half the population, had been fully vaccinated. But COVID cases are climbing nationwide as new vaccinations are stalling and unvaccinated people spread the virus.

Facebook’s spokesperson claimed over the weekend that the platform has been used much more often to disseminate good information about the pandemic and a majority of the platform’s users say they approve of the vaccine.

But a company that knows how to curate individual users’ newsfeed to keep them focused on the site as long as possible is capable of weeding out the false information that discourages people from getting vaccinated.

Allowing the lies to spread allows the virus to spread. It may have been a mistake for Biden to say it, but it was the truth.