Happy Tuesday, Friends.
I know I’ve mentioned the COVID vaccines quite a bit in recent weeks/months, but the truth is, more and more information is released every day. As of this writing, two vaccines have received Emergency Use Authorization (not approval) from the FDA with more to come. Two burning questions:
- What does 90% (or 72% or 50%) efficacy mean for vaccines? Let’s take the 90% example. Vaccine efficacy – or effectiveness is expressed as the proportionate reduction in disease among the vaccinated group. So an effectiveness of 90% indicates a 90% reduction in disease occurrence among the vaccinated group compared to the control group. In other words, if the non-vaccinated group had 100 cases of disease, and the vaccinated group has only 10 cases, this is a 90% efficacy or effectiveness rate. And a 70% efficacy rate translates to a 70% reduction in disease occurence, etc. etc.
- How do the current crop of COVID vaccines work? Science magazine has released this 4-minute YouTube video that explains a bit. It’s a quick watch and I recommend it: