Why vaccinated people dying from Covid-19 doesn't mean the vaccines are ineffective

Former US Secretary of State Colin Powell died on Monday of Covid-19 complications. His family announced that he was fully vaccinated. He was 84 years old, and had multiple myeloma, a blood cancer.

Health officials worry that anti-vaccine activists will seize upon Powell's death to make the claim that vaccines don't work. If you can still die after being vaccinated for Covid-19, what's the point of getting the vaccine?

What's the answer to that question? I discussed it with CNN Medical Analyst Dr. Leana Wen, an emergency physician and professor of health...