The Swedish National Board of Health and Welfare has been producing thorough public statistics over the situation in Sweden ever since the COVID outbreak began. The statistics are accumulated on a weekly basis and cover the number of confirmed infections, number of mild and severe hospitalizations, and the number of deaths. All of it is broken down in age groups as well as grouped according to prior underlying health concerns of the patients.
The statistics accumulated up to the same week the general availability vaccinations began - covering two waves and approx. 14 months of COVID - revealed that for their age group (age 35-45) and with no known underlying health problems, there had been a total of 11 deaths. It's fully understandable that they don't feel threatened by this virus.
And what about those?
Total number of hospitalizations, age group 40-49: 4281
...of which had one or more prior health problems: 65.5%
Total deaths, age group 0-49 (reported as "below 50"): 121
...of which had one or more prior health problems: 85%