Preliminary results from another study with 120 participants under 55 years of age showed that delaying the second dose by up to 45 weeks increases the resulting immune response and that a third dose given at least six months later produces a strong immune response.
The alert said that there were four new reports of serious rare clotting events, including some complicated by low platelet counts, in adults under 65 after receiving the AstraZeneca vaccine.
Quebec also extended eligibility to residents 45 and older.