What's behind the vaccine slowdown?

3. A synthesis view: Vaccination rates were likely destined to slow down in May, but the Johnson & Johnson pause wiped out a great chance at converting the remaining vaccine skeptics. From December to February, the share of Americans who said they’d already received a shot or wanted one as soon as possible rose by 21 points—from 34 percent to 55 percent. In March, that number increased by only six points. In April, it increased by only three points. We’re persuading fewer and fewer people as we approach the solid bloc of vaccine resistance. The Johnson & Johnson shots offered an ideal chance at expanding vaccine enthusiasm at a time when we were running out of eager adults. Across the country, health clinics said that many patients were uniquely excited about the one-shot regimen—due to either skepticism about mRNA technology or fear of needles. Some of that enthusiasm evaporated after the pause, doctors told The Wall Street Journal. That is, the government’s underselling of the vaccines (and overselling of their risks) did not exactly cause the dip, but did make it harder for enthusiasm to bloom among the skeptical.