Johnson & Johnson: A bad week - but fears of negative reactions and blood clots are likely overblown

Johnson & Johnson's coronavirus vaccine rollout hit several unfortunate snags this week - some far worse than others.

The New York Times reported on Tuesday that 62 million of the company's vaccine doses must be checked for contamination, following an error at a Maryland manufacturing plant that already ruined 15 million doses. The plant's workers accidentally mixed up some vaccine ingredients last month.

Then a vaccination site in Colorado, three sites in North Carolina, and one in Georgia all temporarily stopped administering Johnson & Johnson's shot after about 45 people in total experienced minor adverse reactions involving nausea, dizziness, fainting, or lightheadedness.

To top it off, European regulators announced Friday that they are investigating Johnson & Johnson's shot for links to unusual blood clotting after four blood-clot cases, including one death, were reported among vaccine recipients.

The timing of these developments was unfortunate, experts said, but there's no reason to doubt the shot's safety yet.

"You don't want to be fueling unnecessary worries about the safety of vaccines when you're still seeing an enormous outbreak and death rates all over the world from COVID," Art Caplan, a bioethicist at New York University, told Insider.

He added that the side effects observed at the US vaccination sites were "absolutely trivial."

Although symptoms like nausea and fainting aren't common responses to coronavirus vaccines, they aren't abnormal, either.

"When you see these clusters [of side effects], they usually are worked out and have no relation to the vaccine," Arnold Monto, an epidemiologist at the University of Michigan's School of Public Health, told Insider. Monto chairs the Food and Drug Administration's Vaccine Advisory Committee, which voted to recommend the Pfizer, Moderna, and Johnson & Johnson shots.

Most of the negative reactions to Johnson & Johnson's shot occurred within 15 minutes after a person got vaccinated, public-health officials in Colorado, Georgia, and North Carolina reported. In total between the three states, seven people were taken to hospitals for observation. As of Friday, all but one had been released and everyone was expected to fully recover.

Officials haven't yet pinpointed why these clusters of adverse reactions were identified in such a short time frame. But they've emphasized that there's no reason to be concerned about the shot itself.

In a news release, Georgia's public health commissioner, Kathleen Toomey, said the state was looking into "what may have caused the reactions, including the conditions at the fairgrounds such as heat and the ability to keep the site cool." ...