A third dose of Pfizer's COVID-19 vaccine 'likely' - Pfizer CEO
Pfizer began studying a third dose of their vaccine in late February.
https://www.msn.com/en-nz/news/national/a-third-dose-of-pfizers-covid-19-vaccine-likely-pfizer-ceo/ar-BB1fHUmU?ocid=chromentpnews