Infection with adenovirus, a common childhood virus, is the leading hypothesis for recent cases of severe hepatitis of unknown origin in children that have led to at least six deaths, U.S. health officials said on May 20.

The U.S. Food and Drug Administration on May 17 authorized the use of a booster shot of Pfizer and BioNTech’s COVID-19 vaccine for children aged 5 to 11, making everyone in the United States over the age of 5 eligible for a third shot.

A chain of events possibly triggered by unrecognized infection with the SARS-CoV-2 coronavirus could be causing the mysterious cases of severe hepatitis reported in hundreds of young children around the world, researchers suggest.

U.S. health regulators are expected to authorize a booster shot of Pfizer/BioNTech’s COVID-19 vaccine for children aged 5 to 11 as soon as May 17, the New York Times reported on May 16, citing people familiar with the matter.

Moderna, COVID-19 vaccine

Moderna Inc. has made all necessary submissions required by the U.S. Food and Drug Administration for emergency use authorization of the company’s COVID-19 vaccine in adolescents and children.

U.S. health officials on May 6 said they are investigating 109 cases of severe hepatitis of unknown origin in children, including five reported deaths, updating a nationwide alert issued in April for doctors to be on the lookout for such cases of the liver disease.

Asthma in children may worsen after an infection with the coronavirus, doctors warn. Additionally, among people who were previously infected with the coronavirus, a third dose of an mRNA vaccine from Pfizer/BioNTech or Moderna may not boost their protection against the Omicron variant of the virus, according to new data.

The U.S. Food and Drug Administration expanded the indication of Supernus Pharmaceuticals Inc.’s Qelbree (viloxazine extended-release capsules) for the treatment of attention deficit hyperactivity disorder (ADHD) in adult patients aged 18 and older.

Moderna Inc.’s chief medical officer said on Sunday the company’s vaccine for children under 6 years old will be ready for review by a Food and Drug Administration panel when it meets in June.

Moderna Inc. asked U.S. regulators to authorize the company’s COVID-19 vaccine for children under the age of 6, which would make it the first shot against the coronavirus available for those under 5-years-old.