This is the Danish opinion

The purpose of vaccination is not to prevent infection with covid-19, and people aged under 50 are therefore currently not being offered booster vaccination. People aged under 50 are generally not at particularly higher risk of becoming severely ill from covid-19. In addition, younger people aged under 50 are well protected against becoming severely ill from covid-19, as a very large number of them have already been vaccinated and have previously been infected with covid-19, and there is consequently good immunity among this part of the population