How Vaccine Side Effects Compare to COVID Symptoms

The vaccine involved was the Pfizer one, so this analysis may not apply to other vaccines like the Johnson & Johnson. The Moderna vaccine is very similar to Pfizer’s, so it’s likely the results would be similar if the same study could be done with that vaccine—but without the numbers, we don’t know for sure.

“What is even more compelling about these data is the substantial protective effect of vaccines with respect to adverse events such as acute kidney injury, intracranial hemorrhage, and anemia, probably because infection was prevented,” writes Grace Lee, a professor of medicine at Stanford who penned an editorial commentary on the study.


She also notes that the best way to compare risk would include the chance of being exposed to COVID; if it were a rare disease, you’d be much more likely to get a serious adverse event from the vaccine than from being infected, which could change the risk/benefit calculus. But the way the Delta variant is currently raging, COVID is not a rare disease at all.

She writes: “Given the current state of the global pandemic, however, the risk of exposure to SARS-CoV-2 [the virus that causes COVID] appears to be inevitable.”