The Massachusetts Department of Public Health on May 17 said it had confirmed a single case of monkeypox virus infection in a man who had recently traveled to Canada.

Health officials are considering extending the eligibility for a second COVID-19 vaccine booster dose to people under 50 amid a steady rise in cases, with the United States seeing a threefold increase over the past month.

Rising COVID-19 cases are driving up the use of therapeutics, with Pfizer Inc.’s oral antiviral treatment Paxlovid seeing a 315 percent jump over the past four weeks, U.S. health officials said on May 17.

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.

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.

The Janssen COVID-19 vaccine is now limited to certain individuals ages 18 and up after the U.S. Food and Drug Administration downgraded its emergency use authorization.

Following the record surge in COVID-19 cases during the Omicron-driven wave, some 58 percent of the U.S. population overall and more than 75 percent of younger children have been infected with the coronavirus since the start of the pandemic, according to a U.S. nationwide blood survey released on April 26.

Pfizer Inc. and the company’s partner BioNTech SE said on April 26 that they had submitted an application to the U.S. health regulator for the authorization of a booster dose of their COVID-19 vaccine for children aged 5 to 11 years.

COVID-19 was the third leading cause of death in the United States for the second year in a row in 2021, with death rates rising for most age groups, a government study showed on April 22.

The BA.2 sub-variant of Omicron and its sublineage BA.2.12.1 is estimated to make up more than 90 percent of the coronavirus variants in the United States as of April 16, the U.S. Centers for Disease Control and Prevention (CDC) said on April 19.