The risk of reinfection with the Omicron coronavirus variant is more than five times higher and it has shown no sign of being milder than Delta, a study showed, as cases soar across Europe and threaten year-end festivities.

Canadian drug developer Medicago’s plant-based Covid-19 vaccine candidate – enhanced by GlaxoSmithKline’s booster – was 75.3 percent effective against the Delta variant of the virus in a late stage study, the two companies said on December 7.

Survivors of previous infection with the virus that causes SARS-CoV-2 may be at higher risk for reinfection with the Omicron variant than with earlier versions of the virus, preliminary findings show. Additionally, a booster shot of the Pfizer/BioNTech Covid-19 vaccine appears to provide strong protection – at least in the short term – according to data from Israel.

The likelihood that people will need to have an annual Covid-19 vaccine – similar to the influenza shot – is increasing, BioNTech chief executive and co-founder Ugur Sahin told the Reuters Next conference on December 3.

Austria imposed a lockdown on people unvaccinated against the coronavirus on November 15 as winter approaches and infections rise across Europe, with Germany considering tighter curbs and Britain expanding its booster program to younger adults.

The inexpensive antidepressant fluvoxamine might help keep patients with Covid-19 from developing severe disease, according to a study published in The Lancet Global Health. Researchers found in another study that the coronavirus can infect cells of the inner ear, which may help explain the balance problems, hearing loss and tinnitus (ringing in the ears) experienced by some Covid-19 patients.

Two Indian drugmakers requested permission to end their late-stage trials on Merck & Co.’s experimental antiviral drug molnupiravir in moderate Covid-19 patients.

Coronavirus cases worldwide surpassed 200 million on Aug. 4, according to a Reuters tally, as the more-infectious Delta variant threatens areas with low vaccination rates and strains healthcare systems.

A record number of Americans died of drug overdoses during 2020 as pandemic lockdowns made getting treatment difficult and dealers laced more drugs with a powerful synthetic opioid, according to data released on July 14 and health officials.

Pfizer and partner BioNTech plan to ask U.S. and European regulators within weeks to authorize a booster dose of the companies’ Covid-19 vaccine, based on evidence of greater risk of infection six months after inoculation and the spread of the highly contagious Delta variant.