The 175 'Best Hospitals' from U.S. News & World Report, what an internal CDC document reveals about the delta variant, and more.

Is the Pfizer vaccine now just 39% effective? What new research from Israel reveals (and doesn't). (Monday, July 26)

Newly published data from Israel suggests that the Pfizer-BioNTech vaccine may now be just 39% effective at preventing infection with Covid-19 in the country, compared with 95% in the spring—but experts pointed to important limitations in the data, and emphasized that the vaccine continues to provide strong protection against serious illness.

The 175 'Best Hospitals,' according to US News (Tuesday, July 27)

U.S. News & World Report on Tuesday released its 32nd annual Best Hospital rankings, which this year recognizes 175 hospitals for their performance in at least one of 15 specialties.

What CDC's latest mask guidance means for you (Wednesday, July 28)

In an abrupt shift, CDC on Tuesday recommended everyone—including people who have been vaccinated—should wear masks indoors in public in counties with elevated Covid-19 case rates and in schools. Here's how to determine what CDC's recommendations mean for your area.

Pfizer's Covid-19 vaccine is slightly less effective after 6 months. Does that mean 'boosters' are needed? (Thursday, July 29)

Pfizer on Wednesday released data showing its vaccine's effectiveness against symptomatic Covid-19 dips from about 96% to 84% after six months, although no drop-off was seen in protection against severe infections. Here are details on the study—and what experts say it means about the likelihood that Americans will soon need a vaccine "booster" shot.

'The war has changed': Internal CDC document reveals alarming data on the delta variant (Friday, July 30)

A new internal CDC document includes alarming findings about the delta variant, describing "a variant so contagious that it acts almost like a different novel virus," according to the Washington Post. Here's what the document reveals, and what it could mean for the next stage of the epidemic.