Billionaire twin brothers Thomas and Andreas Struengmann have sold around $300 million worth of shares of COVID-19 vaccine-maker BioNTech, Bloomberg reported citing regulatory disclosures. The twins, who still remain a major BioNTech shareholder with 43% stake, had provided the firm with $186 million in seed money in 2008. BioNTech shares have risen over 550% since their IPO in 2019.