A volunteer receives the Covid-19 vaccine from Yaquelin De La Cruz at the Research Centers of America in Hollywood, Florida on August 13, 2020 (Photo by CHANDAN KHANNA / AFP). To establish the degree of certainty of the vaccine’s effectiveness in the real world, an experiment requires tens of thousands …
Read More »The first data on the Covid-19 vaccine is expected on September 15, but how effective will a vaccine be?
