COVID-19 vaccination and the risk of swellings in patients with hereditary angioedema

To date, it is unknown whether short-term prophylaxis before COVID-19 vaccination should be considered, because these vaccines may cause side effects including fatigue, fever, and pain even more frequently than other vaccines.5-7 Furthermore, the new mRNA vaccines may additionally increase the risk of angioedema attacks, because RNA is a potent activator of the contact system.8 We performed a prospective cohort study to assess the angioedema attack rate following COVID-19 vaccination in patients with HAE. Furthermore, the nonrandomized design of our study and the small sample sizes of some vaccine groups do not allow reliable subgroup analyses on patient characteristics or on vaccine types. [...]the signal that attacks occurred mostly after mRNA vaccination requires confirmation from larger cohorts. Characteristic Total mRNA vaccines Vector vaccines No. of patients 63 48 15 No. of administered vaccines 111 87 24 Age (y), mean ± SD 48 ± 15 49 ± 16 46 ± 14 Sex: female, n (%) 42 (67) 31 (65) 11 (73) Long-term prophylaxis, n (%) 45 (71) 39 (81) 6 (40) C1-INH IV 12 (19) 11 (23) 1 (7) Danazol 22 (35) 16 (33) 6 (40) Lanadelumab 1 (2) 1 (2) 0 (0) Tranexamic acid 3 (5) 3 (6) 0 (0) Experimental 8 (13) 8 (17) 0 (0) Short-term prophylaxis, n (%) 4 (6) 4 (8) 0 (0) Well-controlled disease (AECT score ≥ 10), n (%) 42 (67) 31 (65) 11 (73) Previous COVID-19, n (%) 16 (25) 12 (25) 1 (27) Confirmed diagnosis 11 (18) 11 (23) 0 (0) Suspected diagnosis∗ 5 (8) 1 (2) 4 (27) HAE attack, n (% of sum of administered vaccines) 11 (10) 10 (11) 1 (4) Table I Characteristics of COVID-19–vaccinated patients with HAE Patient Age (y) Sex Disease control (AECT score) Long-term prophylaxis Short-term prophylaxis Previous COVID-19 Vaccine Location of attack Maximal attack severity On- demand treatment used Interval between vaccination and attack Attack after first dose Attack after second dose Alternative eliciting factor 1 89 Female Poor: 4 C1-INH IV and danazol NA No Pfizer/BioNtech Abdominal and facial Mild C1-INH IV 24-48 h Yes No Cystitis 2 52 Female Poor: 9 Tranexamic acid NA No Moderna Abdominal Mild Tranexamic acid 48 h Yes No NA 4 47 Female Well: 15 Experimental NA Yes Pfizer/BioNtech Peripheral Mild C1-INH IV 48 h Second