Novavax shares have soared and plummeted in recent years.After losing more than 90% of its value from a peak back in 2021, Novavax (NVAX 2.82%) stock has finally taken off. The biotech soared 190% in two trading sessions after announcing a $1.2 billion vaccine-licensing deal with French pharmaceutical giant Sanofi. The agreement removed one huge worry that's been weighing on the stock: Novavax's ability to continue operations. The vaccine maker issued a going concern early last year, warning that if uncerta ...