Differing strains of the coronavirus continue to appear around the world and a new COVID-19 variant, the so-called "Delta" variant, has health experts concerned. The variant, otherwise known as B.1617 ...

Here’s what the Centers for Disease Control and Prevention (CDC) says about the Delta variant, its symptoms, characteristics and other things to watch for: Viruses constantly change through mutation, ...

The timing of symptom onset depends on lots of factors, including the amount of virus to which someone was exposed, Hotez says. Their level of pre-existing immunity may also affect the likelihood or ...

A new study suggests people vaccinated against COVID-19 can still easily spread the delta variant among households just as likely as people who are unvaccinated. The United Kingdom-based study was ...

LONDON (Reuters) – A subvariant of Delta that is growing in Britain is less likely to lead to symptomatic COVID-19 infection, a coronavirus prevalence survey found, adding that overall cases had ...