That hope, some public health experts fear, is justified.

Almost two years into the coronavirus pandemic, the movement to challenge vaccines' safety — and reject vaccine mandates — has never been stronger. An ideology whose most notable adherents were once religious fundamentalists and minor celebrities is now firmly entrenched among tens of millions of Americans.

The vaccine tore her family apart. Could a death bring them back together?

Baseless fears of vaccines have been a driving force among the approximately 20 percent of U.S. adults who have refused some of the most effective medicines in human history: the mRNA vaccines developed against the coronavirus by Pfizer, with German partner BioNTech, and Moderna. The nation that produced Jonas Salk has exported anti-vaccine propaganda around the globe, wreaking havoc on public health campaigns from Germany to Kenya.

That propaganda has also found its way into many reaches of American life. It has invaded people's offices and shaped the daily decisions of school principals. It has riven families and boosted political campaigns. What was once an overwhelming public consensus on vaccine safety is now a new front in the nation's culture wars. It is no accident that some in the anti-vaccine movement are describing Sunday's rally as their first equivalent of the March for Life, the annual antiabortion rally that took place in Washington on Friday.