"As vaccination is and will remain the best protection, we will set up a new vaccination campaign in the autumn for all those over 50 and all adults who are ill or under treatment," Belgian Health Minister Frank Vandenbroucke announced on Wednesday.
The fourth or fifth dose for the immunocompromised will be given at least three months after the previous vaccination.
People over 50, people aged 65 to 80, and the immunocompromised will receive invitations to vaccinate first, starting in September.
For frontline staff in hospitals and other care facilities, vaccination on request will be possible from this summer onwards.
In Belgium, the average number of new infections per day is 5518, a 44 percent increase in one week, according to figures published on Tuesday by the Belgian public health institute Sciensano.
Faced with a resurgence of new contaminations, with the BA5 variant representing nearly 80 percent of cases, Frank Vandenbroucke advised: "If you have not already done so, make an appointment for the first booster. Get tested if you have symptoms. Apply the barrier gestures to vulnerable people and hide in enclosed spaces if you are vulnerable yourself. Ventilate your indoor spaces."