A recent court ruling has dealt a surprising blow to AstraZeneca, the company behind one of the COVID-19 vaccines. On November 4, a U.S. judge decided that a federal law, which usually protects vaccine makers from lawsuits, does not give AstraZeneca a free pass in a particular case. The lawsuit was brought by a woman named Brianne Dressen, who participated in the company’s vaccine trial in 2020 and claimed to have suffered serious side effects.

Here’s where things get interesting: The la...