A year into the pandemic, the disposable, virus-filtering N95 mask remains a coveted piece of protective gear. Continuing shortages have forced doctors and nurses to reuse their N95s, and ordinary Americans have scoured the internet — mostly in vain — to get them.

But Luis Arguello Jr. has plenty of N95s for sale — 30 million of them, in fact, which his family-run business, DemeTech, manufactured in its factories in Miami. He simply can’t seem to find buyers.

WASHINGTON — Federal health officials are struggling to gather accurate data on the race and ethnicity of people being vaccinated against the coronavirus, hampering President Biden’s push for racial equity in a pandemic that has taken a disproportionate toll on communities of color.

Mr. Biden has repeatedly said racial equity will be at the core of his administration’s coronavirus response. On Tuesday, White House officials announced a program to ship doses of vaccine directly to a network of federally funded clinics in underserved areas, beginning next week.

People with dementia had significantly greater risk of contracting the coronavirus, and they were much more likely to be hospitalized and die from it, than people without dementia, a new study of millions of medical records in the United States has found.

Their risk could not be entirely explained by characteristics common to people with dementia that are known risk factors for Covid-19: old age, living in a nursing home and having conditions like obesity, asthma, diabetes and cardiovascular disease. After researchers adjusted for those factors, Americans with dementia were still twice as likely to have gotten Covid-19 as of late last summer.