AstraZeneca started late-stage trials of an experimental long-acting monoclonal antibody combination drug the company hopes could be used as a so-called prophylactic to prevent Covid-19 infection in at-risk people for up to 12 months.

The UK government’s Covid-19 Vaccine Taskforce and the contract research company Open Orphan announced a $13 million (£10 million) plan to test investigational vaccines in volunteers who are then intentionally exposed to SARS-CoV-2, the virus that causes Covid-19.

Novavax entered into an agreement to provide the United Kingdom with 60 million doses of the company’s Covid-19 vaccine candidate should NVX-CoV2373 be approved, as well as a late-stage efficacy study in the U.K.