For nearly an hour Saturday, about 50 vaccination opponents and right-wing supporters of former President Donald Trump delayed COVID-19 vaccinations when they protested at the entrance to Dodger Stadium, the site of a mass vaccination campaign.

Holding signs that said things such as "COVID=Scam," "Don't be a lab rat" and "Tell Bill Gates to go vaccinate himself," the protesters caused the Los Angeles Fire Department to close the stadium entrance as a precaution. People in hundreds of cars, waiting in line for hours, had to wait even longer.

The site was shut down around 2 p.m. Saturday as several Los Angeles Police Department officers arrived at the scene. No arrests were made, and by 3 p.m., the site was reopened. "We will not be deterred or threatened," California Gov. Gavin Newsom said on Twitter.

Everyone who had been scheduled to receive a vaccine still got their dose, officials said. But the episode highlights the continuing distrust of vaccines by a substantial portion of the public and the unwillingness of some Americans to accept the reality of the coronavirus pandemic, which has killed nearly 440,000 Americans.

"Why are we letting pregnant women become lab rats in real time?" a man in a top hat shouted into a megaphone. Health officials say the vaccine is safe for pregnant women.

Nearby, protesters held signs like "Take off your mask & smell the bulls***" and "CNN is lying to you." The man in the top hat added: "Hydroxychloroquine works!"

It's hard to tell from an isolated protest just how widespread the belief in some of these conspiracy theories is. But according to a December NPR/Ipsos poll, the number may be significant. For instance, the poll showed that about 40% of the American public believes the coronavirus was created in a lab in China and that 17% believe the false QAnon conspiracy theory that politics and the media are controlled by "a group of Satan-worshipping elites who run a child sex ring." (And 37% said they don't know whether that one is true or not.)