The Public Health Agency of Sweden was already recommending a fourth dose of the Covid-19 vaccine for people living in special housing for the elderly and for those receiving home care or home nursing. The recommendation now applies to all people aged 65 or over, as well as people aged 18-64 with medium to severe immune deficiency.

The second booster dose should be offered when four months have passed since the previous vaccination. This period is reduced to three months for people with immune deficiency.

The spread of infection from Covid-19 is continuing in Sweden and increasing in parts of Europe. For people aged 65 or over, it is now almost four months since the previous dose of the vaccine, and the vaccine's protective effect wears off over time.

Those people being offered a fourth dose this spring will probably be offered a new booster dose this autumn to provide enhanced protection ahead of the winter. The Public Health Agency of Sweden will make a decision on this matter later this year.