Report Inappropriate Comments

In his Letter of March 5, Dr. Kees Kolff rightly promotes the COVID-19 vaccines as amazingly effective, breakthrough discoveries. But when he briefly explains what 95 percent effective means he makes a mistake (in company – I might add – with a recent article in Lancet, the leading British medical journal). That 95 percent figure does not mean, as Dr. Kolff suggests, that 5 percent of the recipients of the vaccine will get sick with the virus. A 95 percent efficacy means something different, and probably better in terms of outcomes. It means that in the trials there was a 95 percent reduction in the proportion of positive cases among the vaccinated group as compared with the placebo (unvaccinated) group. So if there were 1000 people in each group and 40 of those in the placebo group got sick, then only 2 people got sick among the 1000 who were vaccinated (not 50, which would be 5 percent). That is a fantastic reduction in risk. And this is what these highly effective vaccines do. They give you an enormous discount in the likelihood for testing positive, and even more so (a 98 percent discount) in how likely you are to become seriously ill.