Everything you need to know about Pfizer's COVID-19 vaccine

This week, as COVID-19 cases continue to climb across the country, there is a glimmer of hope for returning to normal life: a vaccine. Pharmaceutical companies Pfizer and BioNTech say that results from a Phase 3 study of their vaccine candidate look promising and that immunity could last a year. Today, we hear from CBC science and technology reporter Emily Chung on what we know about the Pfizer-BioNTech vaccine that early results suggest is 90 per cent effective in preventing COVID-19.