How effective are the Covid vaccines for our global immunisation efforts?

While there are more than 200 vaccines against Covid-19 being developed, there are now seven vaccines being widely distributed and used around the world. Do they all work? That depends on how you judge “works” often described in terms of  “efficacy” in achieving desired goals. Let’s look at the characteristics of a perfect Covid 19 … Continue reading How effective are the Covid vaccines for our global immunisation efforts? Continue reading »