Mid September, I read a post on social media about an undisclosed nurse in an unnamed hospital, probably somewhere in the province of Antwerp, stating that on intensive care, 75% of the COVID-19 patients were vaccinated, and 25% not. And that this would be similar in another unnamed hospital nearby. And that the writer could not imagine that this would not be the same everywhere.

I’ve got three main objections with this post, coming from my life experience. First of all, this is a story based only on hearsay, without identification of the nurse, the period, the place, or the way of measuring. So not verifiable, and in the best case a local fact, in worst case a fabrication.

Secondly, a limited number of cases (probably only 4 or 8 in that story) do not allow to draw reliable conclusions. During the first period (Aug-Sep 2020) when face masks had to be worn outside in the entire area of the Brussels region, I was curious about the number of people that would follow that rule. So, during my daily walks in my neighbourhood, I counted how many people wore the mask correctly, so not over elbow or chin, and not only over their mouth, but fully covering nose and mouth. When they put up the mask when they saw me, I counted the end result of that action. After the first ten encounters, the rate sometimes really was an extreme 9-1 or 0-10, but by the end of the walk, I got to rates like 19-23 or 30-25. Usually I met 40-60 people and about 50% of them wore the mask correctly, and by the end of September, it reached about 65%. This reminded me again empirically that statistically speaking, measurements become reliable only after 30 or more cases, and that usually there is some variation over time. In the current situation, where in Belgium about 200 people are on IC because of the pandemic, you would have to measure cases over at the least a full province before getting some reliable results, so way more than 1 or 2 hospitals.

Thirdly, generalising results from one limited spot to a bigger area runs a risk of rather weird errors. I live close to the Zavelenberg, in the western part of the Brussels region, where since a few years sheep are grazing the fields. Each time I see them, I check their colour. All of them are always black, without any exception, and sometimes I count more than 30. So statistically speaking reliable and repeatable. After the lambing early 2021, I refined that observation a little: the lambs are truly black, the older generation should rather be called dark brown. But extending this observation to a statement that all sheep in Belgium are black or brown would soon hit the reality that many more observations will be made elsewhere in the country where nearly all sheep are white. So if you measure in an area that is rather homogeneous (like during the first wave, where nobody was vaccinated, or in an area today where 90% is vaccinated), you will indeed find the general clinical picture of mostly older people, with underlying conditions. But if you really want to know whether vaccinations work, you should measure in an area with 50% of people vaccinated. The health care workers in those areas (like in Liege or Brussels today) observe a totally different reality than what the original post described.

So in other words, I would rather base my decisions on verifiable, reliable and relevant information than on unconfirmed stories for the gullible person. However badly I would wish that my environment was different, I do acknowledge the complex reality, even when that is uncomfortable for me. In that way, I find sense in my life, and I continue my path good-humoured.