GlaxoSmithKline (GSK) and Vir Biotechnology have teamed up to develop monoclonal antibodies for respiratory viruses, building off an existing agreement struck last year to develop COVID-19 therapies.

As part of the deal, GSK will co-develop Vir’s intramuscular influenza prophylactic, VIR-2482, which is currently being evaluated in a phase 2 trial. The drugmakers will also develop up to three non-coronavirus or influenza antibodies during a three-year research period, leveraging GSK’s small molecule compounds and Vir’s monoclonal antibody platform.

GSK said it will pay $225 million up front and make a $120 million equity investment in Vir. It also could pay an additional $500 million in development options.