Vaccines Appear to Be Slowing Spread of Covid-19 Infections

Vaccines appear to be starting to curb new Covid-19 infections in the U.S., a breakthrough that could help people return to more normal activities as infection worries fade, public-health officials say.

By Tuesday, 37.3% of U.S. adults were fully vaccinated against Covid-19, with about 2.7 million shots each day. Data from Johns Hopkins University shows the seven-day average for new U.S. cases has fallen below the 14-day average for more than a week, which epidemiologists said is a strong signal that cases are starting to slide again after a recent upswing. When the seven-day average is higher than the 14-day average, it suggests new cases are accelerating.

With the U.S. recently averaging at least 50,000 new daily cases, the pandemic is far from over. But the U.S. is nearing a nationwide benchmark of having 40% of adults fully vaccinated, which many public-health experts call an important threshold where vaccinations gain an upper hand over the coronavirus, based on the experience from further-along nations such as Israel.