Pfizer vaccine provides 90 percent protection against hospitalization for six months, study finds.

The findings, which also document a waning of protection against infection, come as officials debate the necessity and timing of booster shots.

Opinion | Should You Care About Unvaccinated N.B.A. Players?

On the virtues of ignoring famous people’s irrelevant opinions.

Europe’s drug regulator said a booster shot of the Pfizer-BioNTech vaccine could be given to healthy adults.

The European Medicines Agency also said that extra doses of the Moderna and Pfizer-BioNTech vaccines could be given to people with underlying health conditions as early as 28 days after a second dose.

Johnson & Johnson to Seek F.D.A. Authorization for Booster Shot

The request, expected this week, comes after a study found the company’s vaccine was only 71 percent effective against hospitalization from Covid-19.

Johnson & Johnson to Seek F.D.A. Authorization for Booster Shot

The request, expected this week, comes after a study found the company’s vaccine was only 71 percent effective against hospitalization from Covid-19.

Fauci says Americans should get vaccinated even if Merck’s Covid pill cuts deaths.

President Biden’s Covid adviser also says it is “too soon to tell” if the Delta surge will decline enough to allow safe gatherings around the holidays.

Inside United Airlines’ Decision to Mandate Coronavirus Vaccines

Over the course of a year, the company and its unions grappled with when and how to require vaccination for its 67,000 U.S. employees.

California to Mandate Covid-19 Vaccines for All Students as Soon as Next Fall

Children from kindergarten to 12th grade in both public and private schools will be required to be inoculated against the coronavirus once the F.D.A. gives full approval.

F.D.A. Panel to Weigh Pfizer Shots for Children, Boosters for Moderna and Johnson & Johnson Recipients

The timing of the meetings later this month suggests that the agency plans to move quickly to decide both issues.

Is the Coronavirus Getting Better at Airborne Transmission?

The Alpha variant traveled more efficiently in small droplets, two new studies found. The Delta variant may have continued this evolution.

Opinion | Was the Decision on Boosters Bungled?

Readers discuss the government’s handling of the issue. Also: Abortion stories; criminal justice reform; voice recognition; extinct species.

U.S. Coronavirus Death Toll Surpasses 700,000 Despite Wide Availability of Vaccines

The latest Covid-19 deaths were concentrated in the South, and included more younger people than before. Every age group under 55 saw its highest death toll of the pandemic this August.

Justice Kavanaugh tests positive for the virus.

The Supreme Court justice is fully vaccinated, a court spokeswoman said, and is not showing symptoms.

In Portugal, There Is Virtually No One Left to Vaccinate

Portugal is among the most highly vaccinated countries in the world. Vice Adm. Henrique Gouveia e Melo, who led the campaign, said there was a key to his success: Keep politics out of it.

Opinion | Of Vaccine Mandates and Facing Reality

Many Americans said they’d quit if required to take their shots. Luckily they didn’t.

After Mandate, 91% of Tyson Workers Are Vaccinated

The company’s vaccine requirement covers all of its 120,000 U.S. employees. Frontline workers have until Nov. 1 to get inoculated.

How Asia, Once a Vaccination Laggard, Is Revving Up Inoculations

Several countries are now on track to surpass the United States in fully vaccinating their populations, lifting hopes of a more permanent return to normality.

Who Is Suing Over New York’s Vaccine Mandate?

In courtrooms from Manhattan to Utica, judges are weighing whether exemptions that would cover thousands of health care workers will be allowed.

AT&T extends its vaccination mandate to most unionized workers.

The mandate will apply to tens of thousands of employees who are members of the Communications Workers of America union.

AT&T extends its vaccination mandate to most unionized workers.

The mandate will apply to tens of thousands of employees who are members of the Communications Workers of America union.