States Begin a Complex Booster Shot Rollout for Pfizer Recipients

Health officials were preparing on Friday to start giving booster shots to older and at-risk Americans, trying to make sense of new and broad eligibility guidelines.

Biden Promised to Follow the Science. But Sometimes, He Gets Ahead of the Experts.

White House officials dismiss criticism that President Biden’s comments on booster shots amount to undue pressure on public health experts.

States Begin a Complex Booster Shot Rollout for Pfizer Recipients

Health officials were preparing on Friday to start giving booster shots to older and at-risk Americans, trying to make sense of new and broad eligibility guidelines.

Biden Promised to Follow the Science. But Sometimes, He Gets Ahead of the Experts.

White House officials dismiss criticism that President Biden’s comments on booster shots amount to undue pressure on public health experts.

C.D.C. Chief Overrules Agency Panel and Recommends Pfizer-BioNTech Boosters for Workers at Risk

In a highly unusual decision, the C.D.C. director, Rochelle Walensky, reversed a move by agency advisers and endorsed additional doses of the Pfizer-BioNTech vaccine for health care workers, teachers and other workers at risk.

Federal Research Bolsters the Case for Vaccine Mandates

Scientists believe the administration’s new measures may tamp down the pandemic, although the effects will not immediately be obvious.

Unvaccinated Americans should avoid Labor Day travel, the C.D.C. director says.

With the Delta variant spreading and cases, hospitalizations and deaths rising, Dr. Rochelle P. Walensky is urging caution.

Biden Ramps Up Virus Strategy for Nursing Homes and Schools, and Urges Booster Shots

The new strategies — including encouraging booster shots for most vaccinated Americans — reflect concerns that the Delta variant is erasing progress against the pandemic.

Why Not Just Tell Everyone to Wear Masks?

The C.D.C.’s advice about masking up again was not easy to parse. Some experts think simpler would have been better.

Americans Suffer Pandemic Whiplash as Leaders Struggle With Changing Virus

An evolving virus and 18 months of ever-changing pandemic messaging have left Americans angry, exhausted and skeptical of public health advice.

Vaccinated People May Spread the Virus, Though Rarely, C.D.C. Reports

The agency cited an outbreak in Provincetown, Mass., in which most of the infected were immunized. An internal C.D.C. document paints an even more harrowing picture.

Biden Seeks to Revive Vaccine Effort With New Rules and Incentives

The president said those refusing to get a coronavirus shot should expect inconveniences as long as they decline a vaccine.

Behind the Masks, a Mystery: How Often Do the Vaccinated Spread the Virus?

The C.D.C.’s new masking advice was based in part on data showing that the virus can thrive in the airways of vaccinated people. The findings are expected on Friday.

As Infections Rise, C.D.C. Urges Some Vaccinated Americans to Wear Masks Again

In communities with growing caseloads, vaccinated and unvaccinated people should return to wearing masks indoors in public areas, health officials said.

‘Not Out of the Woods’: C.D.C. Issues Warning to the Unvaccinated

The renewed sense of urgency was aimed at millions of people who have not yet been vaccinated and therefore are most likely to be infected.

‘Not Out of the Woods’: C.D.C. Issues Warning to the Unvaccinated

The renewed sense of urgency was aimed at millions of people who have not yet been vaccinated and therefore are most likely to be infected.

C.D.C. Director Warns of a ‘Pandemic of the Unvaccinated’

Cases, hospitalizations and deaths remain far below last winter’s peak, but the director urged people to get fully vaccinated.

Covid Proved the C.D.C. Is Broken. Can It Be Fixed?

The pandemic revealed the glaring weaknesses of the world’s premier public health agency — and just how much work it would take to reform it.

The C.D.C.’s New Leader Follows the Science. Is That Enough?

By all accounts, Dr. Rochelle Walensky is a fierce advocate and an empathetic scientist. But C.D.C. advice must be better attuned to the real world, critics say.

First U.S. Vaccine Donations Will Go to ‘Wide Range’ of Nations in Need

Latin America, South and Southeast Asia and Africa will be among the recipients of an initial 25 million excess doses that the Biden administration is sharing this month.