The U.S. Centers for Diseases Control and Prevention (CDC) on May 19 said reports of heart inflammation linked to the Pfizer/BioNTech COVID-19 vaccine have been much lower in 5- to 11-year-old boys than in adolescents and young men, representing only a slightly elevated rate than normal.

Extending the interval between the first two doses of the most widely used COVID-19 vaccines in the country to eight weeks for young men can reduce the rare risk of heart inflammation, U.S. health officials said.

At least one model from the University of Washington’s Institute for Health Metrics and Evaluation estimates that at this time, 73 percent of Americans are immune to Omicron, and it could rise to 80 percent by mid-March.

Novavax Inc. said on February 10 the company’s two-dose vaccine was 80% effective against COVID-19 in a late-stage trial testing the shot in teens aged 12 to 17 years.

U.S. health officials on Feb. 4 said they are considering lengthening the recommended interval between the first two doses of the most widely used COVID-19 vaccines to eight weeks to lower the risk of heart inflammation and improve their effectiveness.

The U.S. Food and Drug Administration on Jan. 31 gave full approval to Moderna Inc.’s COVID-19 vaccine for people ages 18 and older, making Spikevax the second fully approved vaccine for the virus.

COVID-19 vaccines using mRNA technology do not affect fertility outcomes during in-vitro fertilization (IVF), researchers found. Other new findings suggest the bacteria living in the small intestine may contribute to the risk for long COVID after infection with SARS-CoV-2.

Pfizer released data from several studies showing that nirmatrelvir, the active main protease inhibitor of the company’s antiviral combination therapy Paxlovid (nirmatrelvir/ritonavir), is effective against the Omicron variant of SARS-CoV-2. Additionally, a study conducted by 23andMe and published in Nature Genetics identified a genetic risk factor tied to the loss of smell from COVID-19.

An advisory panel to the U.S. Centers for Disease Control and Prevention (CDC) on Aug. 30 unanimously recommended the Pfizer Inc. and BioNTech SE Covid-19 vaccine for people age 16 and older, an important step that could help accelerate vaccine mandates in the United States.

The use of Pfizer Inc. and German partner BioNTech SE’s widely used Covid-19 vaccine marginally increases the risk of heart inflammation, but the risk is higher among those infected with the coronavirus, a study published on Aug. 25 in the New England Journal of Medicine showed.