You have several options, but if you need this for every patient, it might be best to add a field using Layouts to the Demographic screen. The following view is of a sample patient in an unedited demographic view.
You can go to the layout screen by selecting Administration → Forms → Layouts. You have several options but for your purposes either Demographics or History may work. For demonstration purposes I will put values in History->Other
I will add a field that is a checkbox with the title “Vaccinated”. I will also add a text box so you can add notes if necessary. I select “Add Field”
Then enter in the following information:
I click save. Then I go to the History → Other field and I see my new field.
Using the layout editor can be tedious and sometimes painful, but you can look at other layouts to get an idea of what values to put for “Label Cols” and “Data Cols”.
I hope this helps.