(Reuters) - German biotech firm CureVac plans to sell 5 million shares in a secondary offering, the company said on Monday, as it starts late-stage trials of its COVID-19 vaccine candidate. The proceeds will be used to fund its messenger RNA-vaccine program and expand its in-house manufacturing capacities, the company said. Earlier this month, CureVac struck an alliance with drugmaker Bayer AG to help develop its experimental COVID-19 vaccine. CureVac’s shares fell 3.3% to $101.01 in extended trading on Monday. The Nasdaq-listed company, which is backed by investors Dietmar Hopp, the Gates Foundation and GlaxoSmithKline as well as the German government, has said it aims to produce up to 300 million doses of the vaccine in 2021 and up to 600 million in 2022.