President Joe Biden is justly proud to have seen 215 million COVID-19 shots administered before his 100th day in office.

U.S. death tolls are down to about a quarter of what they were at the end of January. The Centers for Disease Control and Prevention this week announced that it was easing its recommendations for vaccinated people to wear masks while outdoors. Even though the pandemic remains a dire threat around the globe, indications of progress here at home feel like signs of a sorely needed spring.

And yet it is too soon to be taking victory laps. An optimist might say about half the U.S. population has received at least one dose of COVID vaccine. A pessimist would point out that there's about half still to go — and that the second half is likely to be tougher than the first.

The pessimist has a point. A recent Washington Post/ABC News poll found continuing resistance to vaccination among an alarming number of Americans. More than half of those who had not yet gotten vaccinated said they probably or definitely would not do so. Their reluctance could spell trouble for the national effort to tamp down COVID-19 before its variants can propel another wave of the pandemic.

On Tuesday, Biden framed vaccinations as the ticket to a more normal life. "The bottom line is clear," he said. "If you're vaccinated, you can do more things, more safely, both outdoors as well as indoors." He also characterized getting vaccinated as a "patriotic duty."

It's ironic: The distrust the president is trying to overcome may spring in part from the government's determination to act transparently. The Post/ABC poll reveals a particular aversion to the Johnson & Johnson vaccine, which was recently returned to distribution after a federally mandated pause to investigate reports of rare but serious blood clots in some recipients. Unvaccinated people were found to be overwhelmingly reluctant to roll up their sleeves for the J&J vaccine.

It's a shame, for several reasons. First, the J&J vaccine's single dose and convenient storage requirements combine to make it vastly more convenient than the two-shot vaccines that came before it. Second, it's highly effective against COVID-19, especially in preventing hospitalizations and deaths.

Third, the controversy about its safety is the direct result of health officials doing things right — erring on the side of full disclosure, even while knowing that a pause for one vaccine would likely deepen distrust toward all vaccines.

To be clear, clots are known to have developed in 15 people, out of nearly 8 million who have received the J&J vaccine. Three of those patients died, which is three too many. But consider the context: COVID-19 has killed more than half a million Americans so far. And a person is about 18 times more likely to die from being struck by lightning than from a clot following a J&J vaccination.

As the Star Tribune Editorial Board observed earlier this month, the J&J pause is evidence that the U.S. safety system works. It would be perverse to suggest that it works too well — that when the CDC and the Food and Drug Administration raised the alarm, the American public should have remained cool and unperturbed.

The pause was a clear signal to the medical establishment and to consumers that, for some patients in some conditions — particularly for women under age 50 — caution is warranted. Patients being offered the vaccine should be fully informed of the risks, however slight. Doctors must be on the alert for clots and prepared to respond with the appropriate treatment. And patients who want to avoid J&J should have every opportunity to choose an alternative.

But they should also be fully informed of the risks of remaining unvaccinated. If we are truly nearing the end of COVID, this would be a terrible time to catch it.