With the rollout this month of a new coronavirus booster, U.S. public health leaders once more face the challenge of persuading Americans that they should roll up their sleeves and get another, possibly better, shot targeted at the omicron strain.
This has become tougher with each successive vaccination campaign.
About 68% of the U.S. population has received either two doses of the Pfizer-BioNTech or Moderna vaccines or one dose of Johnson & Johnson, but only one-third has chosen to get a booster. In Canada, much of Europe, Japan and South Korea, people have chosen to get additional doses at far higher rates.
This summer, when COVID-19 vaccines were finally authorized in the U.S. for children under 5, they met with low demand. By mid-August, just under 5% of kids under 5 had received their first shots and only about 1% were fully vaccinated.