What happened Shares of vaccine maker CureVac (NASDAQ: CVAC) were sinking 10.8% lower as of 10:43 a.m. ET on Friday. The decline came after investment company dievini and the German government announced the signing of a revised shareholder agreement on Thursday related to their shares in CureVac. With the changes to the shareholder agreement, dievini will sell some of its shares in CureVac to finance a restructuring of the investment company. This restructuring relates to succession planning for German businessman Dietmar Hopp's estate. As part of this succession planning, ownership of dievini will shift to the Hopp family. Current managing co-partners of the investment company will be bought out. Image source: Getty Images. So what Why did the vaccine stock fall on the news of these shareholder agreement changes? The restructuring of dievini means that a large block of CureVac shares will be sold in the near future. Investors are concerned that this could create downward pressure on the price of the German vaccine maker. There was some good news for CureVac, though. Other than the stock sold to finance the restructuring, neither dievini, Dietmar Hopp, Hopp's holding company (DH-LT-Investments), nor the German government currently plan to sell any of their shares of CureVac to third parties. Now what The main thing to watch with CureVac going forward is the company's progress in developing second-generation messenger RNA (mRNA) COVID-19 vaccines in collaboration with GlaxoSmithKline. CureVac and GSK hope to advance a second-generation mRNA candidate into late-stage testing this year. In October, the partners withdrew their first-generation COVID-19 vaccine candidate, CVnCoV, from consideration for approval by the European Medicines Agency. 10 stocks we like better than CureVacWhen our award-winning analyst team has a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* They just revealed what they believe are the ten best stocks for investors to buy right now... and CureVac wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of January 10, 2022 Keith Speights has no position in any of the stocks mentioned. The Motley Fool recommends GlaxoSmithKline. The Motley Fool has a disclosure policy.Source