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.

A large study into rare blood clots linked with AstraZeneca’s COVID-19 vaccine found between just one and three cases per million, and only after the first dose, shedding fresh light on the side effects from the shot.

According to a recent study conducted by researchers at Harvard Medical School and Beth Israel Deaconess Medical Center, 76 percent of the adverse side effects (such as fatigue or headache) that people experienced after receiving their first COVID-19 vaccination were also reported by participants who received a placebo shot.

After a five-day quarantine, about a third of people infected with SARS-CoV-2 might still be infectious, according to new data. In other news, according to research published in the Journal of Primary Care & Community Health, e-cigarette users infected with the coronavirus may be more likely than infected non-vapers to experience COVID-19 symptoms

A safety panel of the European drug regulator on January 14 recommended adding a rare spinal inflammation called transverse myelitis as a side effect of AstraZeneca’s COVID-19 vaccine.

Pfizer Inc and BioNTech SE’s COVID-19 vaccine caused mostly mild side effects in children aged 5 to 11 years, according to data published by the U.S. Centers for Disease Control and Prevention on December 30.

Older adults taking Bayer AG’s blockbuster blood thinner pill Xarelto for a common type of irregular heart rhythm had significantly higher rates of serious bleeding and stroke compared to those taking rival pill Eliquis, a U.S. study showed.

Europe’s drug regulator on November 11 recommended adding a rare type of spinal inflammation called transverse myelitis as a side effect of Johnson & Johnson’s single-dose Covid-19 vaccine.

GlaxoSmithKline said the company’s anemia pill for patients with kidney disease was shown to have about the same side effect risk as the current standard treatment in two important patient groups, a key advantage in a tight race with rival drug developers.

Valneva SE on Oct. 18 said the company’s experimental Covid-19 vaccine demonstrated efficacy “at least as good, if not better” than AstraZeneca’s shot in a late-stage trial comparing the two, with significantly fewer adverse side effects.