The US Food and Drug Administration will now require Covid-19 vaccines from Pfizer/BioNTech and Moderna to use expanded warning labels with more information about the risk of a rare heart condition after vaccination.

Frank DeStefano, MD, MPH, was there when the CDC's Vaccine Safety Datalink (VSD) first came online in 1990, when the agency convinced four health maintenance organizations (HMOs) to contribute data to assess vaccine safety.

In a major policy shift, federal health officials anticipate the shots will be made available to adults 65 and older as well as children and younger adults who have one or more risk factors that make them more vulnerable to severe COVID-19.

In another sign of growing scrutiny over Covid-19 vaccines, the Food and Drug Administration has asked the two makers of mRNA vaccines to widen the age range of boys and young men that their labels say are at risk for a rare side effect causing heart inflammation.

Two global health groups that fund billions of dollars worth of critical medical aid - from childhood vaccines to malaria treatments - are in talks about merging some functions to help combat a financing crunch,

"Again, I don't want to give advice," Kennedy said. "I can tell you, in Europe, they don't use the chickenpox vaccine specifically because the preclinical trial shows that when you inoculate the population for chickenpox, you get shingles in older people, which is more dangerous."

On May 20, U.S. Food and Drug Administration (FDA) officials announced that Covid-19 vaccines will no longer be available to everyone. Instead, annual boosters will be limited to people ages 65 and older, and those with certain medical conditions that put them at high risk for severe infection.