Health-care companies rose on optimism about vaccine developments and deal activity.

Novavax shares rallied after the drug developer started phase 1 human trials of its Covid-19 vaccine treatment, which will test the drug on roughly 130 Australian adults, seeking to establish its safety and ability to provoke an immune response.

Big Pharma company Merck said it's working on two potential vaccines and an experimental drug against the coronavirus, joining rivals in the frantic search for medicines.

AdaptHealth agreed to buy Solara Medical Supplies and ActivStyle for $487 million in cash and stock in a pair of deals that expand its home medical-supplies operations into the diabetes and incontinence markets.

Sanofi took advantage of recent gains to sell its stake in biotech company Regeneron, offloading 23 million shares. 


 Write to Rob Curran at rob.curran@dowjones.com