The United States has a far higher share of seniors without full vaccine protection than many other wealthy countries, a key risk factor driving serious Covid-19 illness and death, a Times analysis shows.

As the Delta variant has torn across the country, America’s pace of vaccinations has sped up after months of relative stagnation, and full federal approval of the Pfizer vaccine on Monday could extend that momentum. Just over half of Americans are now fully vaccinated.

But national averages mask the high rate of older Americans who remain deeply vulnerable. Older people still account for most Covid-19 deaths, and in many counties, especially in the South and Mountain West, seniors without full vaccination make up more than 10 percent of the total population.

“We have swaths of populations in counties who are healthy Americans, over 60, who are not vaccinated,” said Claire Hannan, executive director of the Association of Immunization Managers. “These people are at extreme risk, and they don’t realize it.”

By contrast, unvaccinated seniors in Britain, Spain and Canada are relatively rare. And they are rare there no matter where you live: Those nations also have far fewer disparities between the most and least vaccinated areas, according to local immunization data.

Continue reading at The New York Times.