[nicoburns]

They haven't changed the advice for the initial 2 doses. They have given different advice for additional booster doses. Which, per there own guidance seems to be largely because people already have immunity (either through vaccination or infection), and younger populations are not considered to require additional immunity.

For example, from the second link above (Denmark):

> Why are people aged under 50 not to be re-vaccinated?

> The purpose of the vaccination programme is to prevent severe illness, hospitalisation and death. Therefore, people at the highest risk of becoming severely ill will be offered booster vaccination. 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.