The chief medical officer of BioNTech told CNBC on Wednesday that people will likely need a third shot of its two-dose Covid-19 vaccine as immunity against the virus wanes, agreeing with previous comments made by Pfizer CEO Albert Bourla. Dr. Ozlem Tureci, the co-founder and CMO of BioNTech, which developed a Covid vaccine with Pfizer, said she also expects people will need to get vaccinated against the coronavirus annually, like for the seasonal flu. That’s because, she said, scientists expect vaccine-induced immunity against the virus will decrease over time.