Countries across the globe shut their borders to Britain on Dec. 21 due to fears about a highly infectious new coronavirus strain, causing travel chaos and raising the prospect of food shortages days before Britain is set to leave the European Union.

Two European patients were confirmed to have been re-infected with the coronavirus, raising concerns about people’s immunity to the virus as the world struggles to tame the pandemic.

A roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for Covid-19, the illness caused by the virus.

BioSpace reviews some of the more interesting scientific studies recently published, including a Phase II clinical trial out of Hong Kong that found a three drug-antiviral cocktail significantly decreased median time to a negative SARS-CoV-2 test compared to controls.

The World Health Organization (WHO) said it was “a bit too early” to declare a new coronavirus a global health emergency as China put millions of people on lockdown amid an outbreak that has killed 18 people in the country and infected around 650 globally.

A potential rival for Allergan Plc’s blockbuster Botox passed a late-stage study, putting drug developer Revance Therapeutics Inc. on course to file for U.S. marketing approval in 2019.