A study of the health data of more than 11 million people living in the Canadian province of Ontario, covering the period from 15 January 2020 to 31 August 2021, has shown :
- an increased risk of contracting Covid-19 and of developing a severe form of the disease (hospitalisation, death) for the 4,411 adults with autoimmune myasthenia compared with the general population (n = 22,055), as well as patients with rheumatoid arthritis (n = 22,055);
- a reduction of more than half in the risk of contracting the infection after a first dose of vaccine, a greater effect than in the general population;
- a minimal risk of exacerbation of the disease requiring hospitalisation (< 6/ 3,461) after the first dose of vaccine, and zero after the second dose.
These results support the health authorities’ decision to make myasthenia patients a priority population for access to Covid-19 vaccines and early treatments (antivirals, monoclonal antibodies).
