Hey, Food and Drug Administration: Don’t be rash! Premature approval of a sub-standard Covid-19 vaccine could have dire implications, and not just for this pandemic. It could harm public health for years, if not generations, to come.

Unfortunately, elements now in place make such a disastrous outcome not only possible but in fact quite likely. Specifically, the FDA and its staff of chronically overworked and underappreciated regulators will face enormous public and political pressure to approve a vaccine. Whether or not one worries about an “October surprise” aimed at the upcoming election, regulators will be pressed hard. Some will stand firm. Some may resign in protest. But others could break and allow a bad vaccine to be released.

What makes a “bad vaccine”? Insufficient protection against the disease it is designed for, unwanted side effects, or some combination of the two. If an approved Covid-19 vaccine turns out to be ineffective, this could unintentionally promote wider spread of the disease by individuals who presume they were protected from it. Likewise, a negative experience with one vaccine might discourage the use of other vaccines that are far more safe and effective, whether they are for Covid-19 or other vaccine-preventable diseases.