Now that about 339 million doses of the mRNA vaccines have been administered in the United States under the Emergency Use Authorization of the Food and Drug Administration, and they appear safe and efficacious, why has the agency still not give final licensure or approval? If the conditional authorization is causing people to be hesitant, and preventing institutions such as universities and employers from mandating vaccines, shouldn’t the FDA just give it a stamp of approval? Yes, the FDA must decide soon, but it also must get this right.

So far, 190 million doses of the Pfizer shot and 138 million of the Moderna vaccine have been administered here, and more abroad. By all appearances, these vaccines work splendidly to protect against severe disease and death. Professor Eric J. Topol of Scripps Research argued in a recent op-ed in the New York Times that the vaccines have “overwhelmingly been proved safe and effective by clinical trials, independent research and the experience of millions of people around the world who received them.” He said there has been “more than ample time” for a decision. Moreover, he pointed out that with nearly half of all Americans still unvaccinated, the “emergency” nature of the authorization so far has left many people reluctant — while employers and other organizations, including the military, are waiting for the full approval before instituting vaccine mandates. A stamp of approval from the FDA could give a boost to the flagging vaccination drive.

Dr. Topol’s argument reflects common sense, but there are good reasons to show a bit more patience with the FDA. The hundreds of millions of shots successfully administered so far are a positive result, but access to patient data from those vaccinated across the country is selective and fragmentary, and not being used for the FDA’s review. The agency’s decision is being based on a set of about 40,000 individuals in clinical trials over about six months. In addition to looking at vaccine safety and effectiveness on people, the FDA must also assure the highest manufacturing quality, and that means extensive checking of factories and manufacturing processes, which are expanding. A priority review such as this one has a six-month maximum window, but the FDA says it will be completed “far in advance” of that. Three or four months is possible. Pfizer’s Biologic License Application was submitted May 7, and Moderna’s on June 1. So the decision is not too far off.

But the most important reason to wait is the integrity of the process itself. If vaccination is the key to ending the pandemic, then the review must be persuasive and above reproach. If shortcuts or haste lead to questions about the review, it would shake public confidence just when confidence is vital. The best analogy is a pit crew in an auto race: There is no victory if someone decides to save time by neglecting to fully tighten the lug nuts on every wheel.

The FDA must sprint, but not stumble.