The Wuhan-wide study shows infection risk varies with various factors.
Laboratory workers would presumably spend more of their work day in conditions that lower infection risk, unlike, for instance, store employees exposed to infected people
Infection rates vary by location, even in populations that don't have more procedures + equipment preventing them from being infected (ex: outpatients).
Makes it more unsurprising that infection rate could be lower among lab workers tied to 1 site
So we have a bunch of paranoid non-experts running a shoddy calculation that doesn't take into account things like time-frame, infection clustering, infection-preventing behavior, location, etc.
In the slide below, Ioannidis discusses age-specific IFR (infection fatality rate), i.e. what proportion of SARS-CoV-2-infected people die of the disease COVID-19 at various ages.
For context:
This is not the first time Nicholas Wade said nonsense outside his field of expertise to suit his preferred ideologically-motivated narrative, despite experts correcting him.