BioNTech's co-founder and chief executive said he was optimistic that the protective effect of its experimental COVID-19 vaccine, co-developed with Pfizer, would last for at least a year. The two companies earlier on Monday became the first drugmakers to release successful trial data, saying their vaccine was shown to be more than 90% effective, a major victory in the fight against the pandemic. "We should be more optimistic that the immunisation effect can last for at least a year," CEO Ugur Sahin told Reuters.