Vaccine effectiveness against COVID-19 infection dropped from 91% to 66% once the delta variant accounted for the majority of circulating virus, according to a study published Tuesday by the U.S.

The Centers for Disease Control and Prevention listed the COVID-19 delta variant as one of its "variants of concern" (VOCs) on June 15. According to the CDC, VOCs can be more contagious, more ...

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 ...

Planning an international vacation was stressful enough before COVID-19 emerged. Now, the pandemic has travelers jumping through even more hoops. Certain countries have lifted travel restrictions ...

At 12 months, risk factors for persistence of long COVID symptoms included male sex, fever, and taste disorder.

Currently, the COVID-19 Delta variant has been reported in 60 countries and accounts for less than 6 percent of COVID-19 cases in the U.S. After months of steady decline in COVID-19 cases, the United ...

Canada's main stock index fell to its lowest level in nearly three weeks on Wednesday as investors weighed rising global ...

Increased risk of DENV-infection (primarily DENV3) was observed up to 300 days post-SARS-CoV-2 infection (predominantly ...

Canada's main stock index fell for a fourth day on Tuesday, as the spreading Delta variant of the coronavirus contributed to ...

Part of the problem is low vaccination rates, experts said. The Centers for Disease Control and Prevention assigned two federal "surge team" members to Missouri this week to help fight the state's ...

Estimates show the variant accounts for over 51% of all new cases nationwide. A highly contagious variant of the novel coronavirus that was initially identified in India is now the dominant strain in ...